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33444 (2)31 OZ 11111111E, CITY OF LA QUINTA CEQA Environmental Checklist and Assessment TENTATIVE TRACT MAP NO. 33444 Prepared ;By City of La Quinta Community Development Department 78 -495 Calle Tampico La Quinta, CA 92253 Project Location South of Quarry Ranch subdivision and being a portion of the E1 /2 of the S1 /2 of Section 29, T.6S., R.7E, SBBM. APN: 766-020-004,'005,006, 0079 0089 0099 010, & 011. Applicant Coral Mountain Trails, LLC 74 -001 Reserve Drive Indian Wells, CA 92210 August 25, 2005 CITY OF LA QUINTA CEQA Environmental Checklist and Assessment TENTATIVE TRACT MAP NO. 33444 Prepared By City of La Quinta Community Development Department 78 -495 Calle Tampico La Quinta, CA 92253 Project Location South of Quarry Ranch subdivision and being a portion of the E1 /2 of the S1 /2 of Section 29, T.6S., R.7E, SBBM. APN: 766 - 020 -004, 005, 006, 007; 0089 0099 0109 & 011. Applicant Coral Mountain Trails, LLC 74 -001 Reserve Drive Indian Wells, CA 92210 August 25, 2005 TN /City of La Quinta TTM 33444 EA/8.25.05 Table of Contents CEQA Initial Study Project Description Aesthetics Agricultural Resources Air Quality Biological Resources Cultural Resources Geology and Soils Hazards and Hazardous Materials Hydrology and Water Quality Land Use and Planning Mineral Resources Noise Population and Housing Public Services Recreation Transportation and Traffic Utilities and Service Systems Mandatory Findings Earlier Analysis Initial Study Exhibits Appendices /Special Studies General Biological Resources Assessment/AMEC Earth & Environmental Cultural Resources Survey/The Keith Companies Geotechnical Investigation/Sladden Engineering Slope Stability/ Geotechnical Investigation /Sladden Engineering Hydrology Assessment/Pacific Advanced Civil Engineering Focused Traffic Analysis /Urban Crossroads 1 1 4 5 6 10 14 15 17 19 22 24 25 26 27 28 29 31 33 34 36 TN /City of La Quinta / Page 1 TTM 33444 EA/8.25.05 CITY OF LA QUINTA Environmental Checklist Form 1. Project title: Tentative Tract Map No. 33444 2. Lead agency name and address: City of La Quinta 78-495 Calle Tampico La Quinta, CA 92253 3. Contact person and phone number: Fred Baker 760 - 777 -7125 4. Project location: South of Quarry Ranch subdivision and being a portion of the EI /2 of the S1 /2 of Section 29, T.6S., R.7E, SBBM. APN: 766-020-004,005, 006, 007, 008, 009, 010, & 011. 5. Project sponsor's name and address: Coral Mountain Trails, LLC 74-001 Reserve Drive Indian Wells, CA 92210 6. General Plan Designation: (LDR) Low Density Res. 7. Zoning: (RL) Low Density Residential 8. Description of project: (Describe the whole action involved, including but not limited to later phases of the project, and any secondary, support, or off -site features necessary for its implementation. Attach additional sheets if necessary.) The proposed Tentative Tract Map No. 33444 encompasses approximately 317.61± acres, of which approximately 78.78 acres is proposed for development of residential lots and associated lettered lots representing common open space and recreation areas. The tract map will allow the development of almost all residences allowed under the Green Specific Plan, which it implements. Of the 266 dwelling units allowed in the TTM residential area under the Specific Plan, 219 units are proposed and represent a 17% reduction in density. The proposed subdivision map also adjusts existing lot lines created by approved and recorded Parcel Map No. 28617. Total open space lands outside the residential portion of the project totals 225.54± acres, versus the 231.2 acres set forth in the Green Specific plan. The residential portion of the subdivision is located in the eastern most portion of the holding. The subdivision also accommodates and will take direct access from the future Jefferson Street alignment already dedicated to the City. A network of internal paths and trails are also planned throughout and along much of the perimeter of the residential development site. Emergency /secondary access is to be provided via a crash gate access to the Quarry Ranch subdivision located immediately north of the TTM 33444 development site, in accordance with the City Fire Marshall requirements. At the recommendation of the California Department of Fish and Game, the applicant has also filed a California Fish and Game Code Section 1602 Streambed Alteration Agreement, which is also assessed in this Initial Study. Excluded from the subject subdivision map is a 12.5± acre parcel (Parcel 3) created by Parcel Map No. 28617, which is approved for up to 10 residential lots per the Green Specific Plan Amendment No. 1. This parcel is expected to take access from within the existing Quarry. development. Previously approved alternative access to this parcel (Lot B of PM 28617) would be eliminated by the subject TTM 33.444 and incorporated as part of the residential subdivision and as common open space. -1- TN /City of La Quinta / Page 2 TTM 33444 EA/8.25.05 9. Surrounding land uses and setting: Briefly describe the project's surroundings: North: Quarry Ranch subdivision and golf South: Unincorporated/BLM lands - vacant desert West: Vacant desert lands designated as open space and hillside overlay East: Vacant desert lands under public ownership; designated golf course open space 10. Other public agencies whose approval is or may be required (e.g., permits, financing approval, or participation agreement.) Coachella Valley Water District, USBR (Encroachment Permit), CDFG (1602 SAA) ENVIRONMENTAL FACTORS F The environmental factors checked one impact that is a "Potentially Sig Aesthetics X Biological Resources Hazards & Haz. Mat.s LJ Mineral Resources Public Services Utilities / Service Systems OTEN below i nifican ■ TIALLY AFFECTED: vould be potentially affected by this project, involving at least t Impact" as indicated by the checklist on the following pages. Agriculture Resources X Air Quality Cultural Resources X Geology /Soils Hydrology/Water Qual. Land Use / Planning Noise Population / Housing Recreation X Transportation/Traffic Mandatory Findings of Significance I' DETERMINATION: (To be completed by the Lead Agency) On the basis of this initial evaluation: I find that the proposed project COULD NOT have a significant effect on the environment, and a NEGATIVE DECLARATION will be prepared. I find that although the proposed project could have a significant effect on the environment, there X will not be a significant effect in this case because revisions in the project have been made by or agreed to by the project proponent. A MITIGATED NEGATIVE DECLARATION will be prepared. I find that the proposed project MAY have a significant effect on the environment, and an ENVIRONMENTAL IMPACT REPORT is required. I find that the proposed project MAY have a "potentially significant impact" or "potentially significant unless mitigated" impact.on -the environment, but at least one effect 1) has been adequately analyzed in an earlier document pursuant to applicable legal standards, and 2) has been addressed by mitigation measures based on the earlier analysis as described on attached sheets. An ENVIRONMENTAL IMPACT REPORT is required, but it must analyze only the effects that remain to be addressed. I find that although the proposed project could have a significant effect on the environment, because all potentially significant effects (a) have been analyzed adequately in an earlier EIR or NEGATIVE DECLARATION pursuant to applicable standards, and (b) have been avoided or mitigated pursuant to that earlier EIR or NEGATIVE DECLARATION, including revisions or mitigation measures that are imposed upon the proposed project, nothing further is required. 8 -,-L �- -©5 e (Fred Baker, al Planner) Date -2- TN /City of La Quinta / Page 3 TTM 33444 EA/8.25.05 EVALUATION OF ENVIRONMENTAL IMPACTS: 1) A brief explanation is required for all answers except "No Impact" answers that are adequately supported by the, information sources a lead agency cites in the parentheses following each question. A "No Impact" answer is adequately supported if the referenced information sources show that the impact simply does not apply to projects like the one involved (e.g., the project falls outside a fault rupture zone). A "No Impact" answer should be explained where it is based on project - specific factors as well as general standards (e.g., the project will not expose sensitive receptors to pollutants, based on a project- specific screening analysis). 2) All answers must take account of the whole action involved, including off -site as well as on -site, cumulative as well as project - level, indirect as well as direct, and construction as well as operational impacts. 3) Once the lead agency has determined that a particular physical impact may occur, then the checklist answers must indicate whether the impact is potentially significant, less than significant with mitigation, or less than significant. "Potentially Significant Impact" is appropriate if there is substantial evidence that an effect may be significant. If there are one or more "Potentially Significant Impact" entries when the determination is made, an EIR is required. 4) "Negative Declaration: Less Than Significant With Mitigation Incorporated" applies where the incorporation of mitigation measures has reduced an effect from "Potentially Significant Impact" to a "Less Than Significant Impact." The lead agency must describe the mitigation measures, and briefly explain how they reduce the effect to a less than significant level (mitigation measures from Section XVII, "Earlier Analyses," may be cross - referenced). 5) Earlier analyses may be used where, pursuant to the tiering, program EIR, or other CEQA process, an effect has been adequately analyzed in an earlier EIR or negative declaration. Section 15063(c)(3)(D). In this case, a brief discussion should identify the following: a) Earlier Analysis Used. Identify and state where they are available for review. b) Impacts Adequately Addressed. Identify which effects from the above checklist were within the scope of and adequately analyzed in an earlier document pursuant to applicable legal. standards, and state whether such effects were addressed by mitigation measures based on the earlier analysis. C) Mitigation Measures. For effects that are "Less than Significant with Mitigation Measures Incorporated," describe the mitigation measures, which were incorporated or refined from the earlier document and the extent to which they address site - specific conditions for the project. 6) Lead agencies are encouraged to incorporate into the checklist references to information sources for potential impacts (e.g., general plans, zoning ordinances). Reference to a previously prepared or outside document should, where appropriate, include a reference to the page or pages where the statement is substantiated. 7) Supporting Information Sources: A source list should be attached, and other sources used or individuals contacted should be cited in the discussion. 8) This is only a suggested form, and lead agencies are free to use different formats; however, lead agencies should normally address the questions from this checklist that are relevant to a project's environmental effects in whatever format is selected. 9) The explanation of each issue should identify: a) the significance criteria or threshold, if any, used to evaluate each question; and b) the mitigation measure identified, if any, to reduce the impact to less than significance -3- TN /City of La Quinta / Page 4 TTM 33444 EA/8.25.05 ' Sources: Site surveys; Aerial topography; BLM Property ownership maps; Green SP and associated FIR and Addendum, Proposed TTM 33444 ' Findings of Fact I. a) -d) The proposed project is not located on a General Plan Image Corridor. The subject property, particularly the eastern development site as described in the Green Specific Plan and incorporated into TTM 33444, has been impacted by limited pedestrian and jeep trails, dumping of domestic and construction ' trash, and disturbance from off -site development encroachment into the north- central portion of the site. The residential portion of TTM 33444 lies between the isolated Coral Rock (aka Coral Mt.) formation and the continuous foothills that make up most of the balance of the subject property to the west. ' The residential development site lies within the partial viewshed of The Quarry and Quarry Ranch developments, and is bounded on the south and east by public lands (BLM and USBR, respectively). However, the residential site is surrounded on three sides by elevated terrain and is. isolated from most ' views. The proposed subdivision generally follows the natural terrain and utilizes slope areas within the subdivision to provide development pads, which will complement the existing landforms. The applicant proposes complementary architecture and palette of materials that will further blend the ' development with the surrounding viewshed. Although these provisions are a limited part of the development plan being analysed in this EA, building siting, and building and landscape architecture will also be subject to the design guidelines set forth in the Green Specific Plan. ' Access to the residential site will be via Jefferson Street, a General Plan roadway, which is projected to have limited traffic volumes at project and area -wide buildout. The ultimate construction of Jefferson Street and the single family homes on the site will result in a slight/less than significant increase in light generation, ' primarily from car headlights and landscape lighting. The City regulates development lighting levels, and buildout impacts will not be significant. Mitigation Measures ' Architectural Review: The applicant shall provide and the City shall review proposed building and landscape architecture for TTM 33444 and assure that building and other design, materials and landscape palettes reasonable complement the surrounding viewshed. Building and landscape architecture and ' associated materials and color palettes shall substantially conform to the design guidelines set forth in the Green Specific Plan, as amended. -4- Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact I. AESTHETICS -- Would the project: a) Have a substantial adverse effect on a X scenic vista? b) Substantially damage scenic resources, X including, but not limited to, trees, rock outcroppings, and historic buildings within a state scenic highway? c) Substantially degrade the existing visual X character or quality of the site and its surroundings? d) Create a new source of substantial light X or glare, which would adversely affect day or nighttime views in the area? ' Sources: Site surveys; Aerial topography; BLM Property ownership maps; Green SP and associated FIR and Addendum, Proposed TTM 33444 ' Findings of Fact I. a) -d) The proposed project is not located on a General Plan Image Corridor. The subject property, particularly the eastern development site as described in the Green Specific Plan and incorporated into TTM 33444, has been impacted by limited pedestrian and jeep trails, dumping of domestic and construction ' trash, and disturbance from off -site development encroachment into the north- central portion of the site. The residential portion of TTM 33444 lies between the isolated Coral Rock (aka Coral Mt.) formation and the continuous foothills that make up most of the balance of the subject property to the west. ' The residential development site lies within the partial viewshed of The Quarry and Quarry Ranch developments, and is bounded on the south and east by public lands (BLM and USBR, respectively). However, the residential site is surrounded on three sides by elevated terrain and is. isolated from most ' views. The proposed subdivision generally follows the natural terrain and utilizes slope areas within the subdivision to provide development pads, which will complement the existing landforms. The applicant proposes complementary architecture and palette of materials that will further blend the ' development with the surrounding viewshed. Although these provisions are a limited part of the development plan being analysed in this EA, building siting, and building and landscape architecture will also be subject to the design guidelines set forth in the Green Specific Plan. ' Access to the residential site will be via Jefferson Street, a General Plan roadway, which is projected to have limited traffic volumes at project and area -wide buildout. The ultimate construction of Jefferson Street and the single family homes on the site will result in a slight/less than significant increase in light generation, ' primarily from car headlights and landscape lighting. The City regulates development lighting levels, and buildout impacts will not be significant. Mitigation Measures ' Architectural Review: The applicant shall provide and the City shall review proposed building and landscape architecture for TTM 33444 and assure that building and other design, materials and landscape palettes reasonable complement the surrounding viewshed. Building and landscape architecture and ' associated materials and color palettes shall substantially conform to the design guidelines set forth in the Green Specific Plan, as amended. -4- TN /City of La Quinta / Page 5 ' TTM 33444 EA/8.25.05 Lighting: Common area, pedestrian and other project lighting shall utilize the lowest levels of illumination practicable. No upward lighting of mountain slopes shall be permitted. Landscape lighting shall be shielded i' to direct and limit areas of illumination. Lighting plans shall be provided with project building and landscape plans, and very reasonable effort shall be made to protect night skies. Hillside Conservation Ordinances: The project engineer has provided a slope and design analysis of the project, which demonstrates that the proposed subdivision, including development lots and roads, can be accomplished in a manner that will not violate the City's hillside conservation districts and ordinances (City Hillside Conservation Overlay District (9.110.070) and Conservation Regulations (9.140.040)). ' Mitigation Monitoring and Reporting 1. The City architectural review process shall provide this function, reviewing and approving building and landscape architecture, as well as required lighting plans. Said plans shall be approved prior to ' issuance of building permits. 2. The Community Development Department and City Engineer shall review the tentative map and ' grading plans to further assure conformance with the provisions of the City Hillside Conservation Overlay District (9.110.070) and Conservation Regulations (9.140.040). Conformance shall be assured prior to recordation of the final map Sources: La Quinta General Plan, Riverside County General Plan, California Farmland Mapping and Monitoring Program. Findings of Fact II. a)-c) The proposed project is not currently in agriculture, nor are there Williamson Act contracts on the subject property. Development of the site will not impact agricultural resources. No mitigation measures associated with Green EIR (SCH#94112047) or associated addendum. Mitigation Measures None required Mitigation Monitoring and Reporting None required. -5- Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact II. AGRICULTURE RESOURCES: Would the ro'ect: a) Convert Prime Farmland, Unique X Farmland, or Farmland of Statewide Importance (Farmland), as shown on the maps prepared pursuant to the Farmland Mapping and Monitoring Program of the California Resources Agency, to non- agricultural use? b) Conflict with existing zoning for X agricultural use, or a Williamson Act contract? c) Involve other changes in the existing X environment which, due to their location or nature, could result in conversion of Farmland, to non - agricultural use? Sources: La Quinta General Plan, Riverside County General Plan, California Farmland Mapping and Monitoring Program. Findings of Fact II. a)-c) The proposed project is not currently in agriculture, nor are there Williamson Act contracts on the subject property. Development of the site will not impact agricultural resources. No mitigation measures associated with Green EIR (SCH#94112047) or associated addendum. Mitigation Measures None required Mitigation Monitoring and Reporting None required. -5- TN /City of La Quinta / Page 6 TTM 33444 EA/8.25.05 Sources: La Quinta General Plan and EIR; SCAQMD EIR Handbook, CV SIP 2002 for PM10; Urban Cross -roads Green SP Focused Traffic Analysis Findings of fact III. a), b) & c) The two primary pollutants of concern in the Coachella Valley are PM10 and ozone. The Coachella Valley has a history of exceeding regulatory ozone standards, although the number of days and months the Federal one -hour standard has been exceeded has dropped steadily over the past decade. The Coachella Valley is classified as a "severe -17" ozone non - attainment area under the Federal Clean Air Act This classification means that the region must come into compliance with Federal ozone standards by November 15, 2007, which is 17 years from the date the Clean Air Act was enacted. SCAQMD, in conjunction with local jurisdictions, prepared the 2002 Coachella Valley PM10 State Implementation Plan, which includes PM10 control program enhancements and requests an extension of the region's PM10 attainment date. In the near -term, potential impacts to air quality from the proposed development may result from site grading and associated construction activities. The Coachella Valley is in a sever non - attainment area for PM10 and is subject to the 2002 SIP and local dust control guidelines. The proposed tract map will result in the disturbance of approximately 78.78 acres for residential lots, streets and drainage facilities. A total of 219 residences are proposed, along with a 3,500± square foot recreation building, which could generate up to 880. trips per day'. Based on the extent of site disturbance and post - development traffic generation with an average trip length of 6 miles, the following emissions can be expected to be generated from the project site. The 1995 City EA for the Jefferson Street alignment study addressed air quality impacts. These will again be addressed in detail in the. new Jefferson Street EA. "Focused Analysis for the Green Specific Plan Residential Development" prepared by Urban Crossroads, March 23, 2005. A trip generation rate of 4.0 average daily trips (ADT) per unit was applied based upon the residential product being comprised of retiree and vacation/2' home residents. This compared to the trip rate of about 9.5 ADT assumed in the original EIR. -6- Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact III. AIR QUALITY: Would the project: a) Conflict with or obstruct X implementation of the applicable air quality plan? b) Violate any air quality standard or con- X tribute substantially to an existing or pro - jected air quality violation? c) Result in a cumulatively considerable X net increase of any criteria pollutant for which the project region is non - attainment under an applicable federal or state ambient air quality standard (including re- leasing emissions, which exceed quantita- tive thresholds for ozone precursors)? d) Expose sensitive receptors to X substantial pollutant concentrations? e) Create objectionable odors affecting a X substantial number of people? Sources: La Quinta General Plan and EIR; SCAQMD EIR Handbook, CV SIP 2002 for PM10; Urban Cross -roads Green SP Focused Traffic Analysis Findings of fact III. a), b) & c) The two primary pollutants of concern in the Coachella Valley are PM10 and ozone. The Coachella Valley has a history of exceeding regulatory ozone standards, although the number of days and months the Federal one -hour standard has been exceeded has dropped steadily over the past decade. The Coachella Valley is classified as a "severe -17" ozone non - attainment area under the Federal Clean Air Act This classification means that the region must come into compliance with Federal ozone standards by November 15, 2007, which is 17 years from the date the Clean Air Act was enacted. SCAQMD, in conjunction with local jurisdictions, prepared the 2002 Coachella Valley PM10 State Implementation Plan, which includes PM10 control program enhancements and requests an extension of the region's PM10 attainment date. In the near -term, potential impacts to air quality from the proposed development may result from site grading and associated construction activities. The Coachella Valley is in a sever non - attainment area for PM10 and is subject to the 2002 SIP and local dust control guidelines. The proposed tract map will result in the disturbance of approximately 78.78 acres for residential lots, streets and drainage facilities. A total of 219 residences are proposed, along with a 3,500± square foot recreation building, which could generate up to 880. trips per day'. Based on the extent of site disturbance and post - development traffic generation with an average trip length of 6 miles, the following emissions can be expected to be generated from the project site. The 1995 City EA for the Jefferson Street alignment study addressed air quality impacts. These will again be addressed in detail in the. new Jefferson Street EA. "Focused Analysis for the Green Specific Plan Residential Development" prepared by Urban Crossroads, March 23, 2005. A trip generation rate of 4.0 average daily trips (ADT) per unit was applied based upon the residential product being comprised of retiree and vacation/2' home residents. This compared to the trip rate of about 9.5 ADT assumed in the original EIR. -6- TN /City of La Quinta / Page 7 TTM 33444 EA/8.25.05 Calculations of Fugitive Dust Potential Unmitigated Condition Total Area to be Total Potential Excavated/Disturbed Factor Dust Generation ' 80t acres 26.4 lbs. /day /acre 2,1121bs. /day Sources: Table A9 -9, "CEQA Air Quality Handbook," prepared by South Coast Air Quality Management District, April 1993;TTM 33444 Estimated Grading Equipment Emissions (pounds per day) t# # Equipment Pieces hrs /day CO ROC NOx Sox PM, 0 Trucks - Off- Highway 11 8 158.400 16.720 366.960 39.600 22.880 ' Tracked Loader 1 9 1.809 0.855 7.470 0.684 0.531 Tracked Tractor 1 10 3.500 1.200 12.600 1.400 1.120 Scraper 1 8 10.000 2.160 30.720 3.680 3.280 Wheeled Dozer 1 8 - - - 2.800 1.320 Motor Grader 1 8 1.208 0.312 5.704 0.688 0.488 ' Total: 174.917 21.24711 423.454 48.852 29.615 SCAQMD Thresholds of Significance 550.00 75.00 100.00 150.00 150.0( Source: South Coast Air Quality Management District, " Air Quality Handbook," Table A- 9 -8 -A. Construction Workers Moving Exhaust Emission Projections (pounds per day) Ave. Trip Total ' Total No. Vehicle Trips/Day Length (miles) miles /day 40 x 25 1,000 ' Pollutant ROG CO NOx Sox PM10 Pounds per day 1.77 16.56 1.80 0.01 0.11 ' Based on California Air Resources Board Highest EMFAC 2002 (version 2.2) Emissions Factors for On -Road Vehicles. Based upon Year 2004 emission factors. All the emission factors account for the emissions from start, running and idling exhaust. In addition, the ROG emission factors take into account diurnal, hot, soak, running, and resting emissions, and PM10 emission factor takes into account the tire and brake wear. ere TN /City of La Quinta / Page 8 TTM 33444 EA/8.25.05 Moving Exhaust Emission Projections at Project Buildout (pounds per day) , Ave. Trip Total Total No. Vehicle Trips/Day Length (miles) miles /day 880 x 6 = 5,280 Pollutant ROG CO NOX Sox PM, o Emission Factor 0.001383 0.01282 0.001361 0.000009 0.000115 Pounds at 50 mph 7.302 67.68 7.18 0.047- 0.6072 SCAQMD Threshold (lbs. /day) 75 550 100 150 150 Assumes 880 ADT based on 220 units of resort/retirement single family housing. Based on California Air Resources Board's EMFAC7G Emissions Model. Assumes Year 2007 summertime running conditions at 75 °F, light duty autos, catalytic. As indicated by the above analysis, grading activities associated with the residential subdivision have the potential to generate levels of fugitive dust and NOx in excess of the SCAQMD daily emission threshold. It should be noted that these impacts are short-term and will occur over a limited period of time and then will end. As shown above, post - grading construction activities are projected to result in negligible emission of monitored pollutants. Project traffic has the greatest potential to impact regional air quality. As shown in the moving emissions table for project buildout, long -term impacts will be well below all SCAQMD thresholds. In the long -term, the proposed tract map will contribute 58% less pollutants than projected in the Green Specific Plan EIR, with a substantial decrease in total dwelling units and trips generated. As noted above, the City and Coachella Valley area severe non - attainment area for PM10 (particulates of 10 microns or less). The Valley's 2002 PM10 Plan adopted much stricter measures for the control of dust to be implemented during the site grading and development phase. These measures will be integrated into conditions of approval for the proposed project. These include the following control measures. III. d) & e) The project will consist of single family homes and will not result in objectionable odors, nor will it expose residents to concentrations of pollutants. Mitigation Measures A variety of mitigation measures are available to and will be required by the City as a part of the grading permit, which must include a detailed dust control plan conforming to the City dust control ordinance. In addition, the following Best Control Measures (BCMs) are described below and shall be applied as deemed appropriate by the City Building Department. CONTROL MEASURE TITLE & CONTROL METHOD BCM -1 Further Control of Emissions from Construction Activities: Watering, chemical stabilization, wind fencing, revegetation, track -out control BCM -2 Disturbed Vacant Lands: Chemical stabilization, wind fencing, access restriction, revegetation BCM -3 Unpaved Roads and Unpaved Parking Lots: Paving, chemical stabilization, access restriction, revegetation BCM -4 Paved Road Dust: Minimal track -out, stabilization of unpaved road shoulders, clean streets maintenance The proposed project will generate dust during construction. Under high winds and uncontrolled conditions, grading could result in the generation of up to 2,112 pounds per day, for a limited period. The bulk of the grading will occur during the first few weeks of site development. The grading contractor will be required to submit a PM10 Management Plan prior to initiation of grading. The grading plan shall -8- TN /City of La Quints / Page 9 TTM 33444 EA/8.25.05 provide for the most efficient management of cut and fill activities and net export practicable. In addition, the potential impacts associated with PM10 can be mitigated by the measures below. 1. Construction equipment shall be properly maintained and serviced to minimize exhaust emissions. 2. Existing power sources should be utilized where feasible via temporary power poles to avoid on -site power generation. 3. Construction personnel shall be informed of ride sharing opportunities. 4. Imported fill and exported excess cut shall be adequately watered prior to transport, covered during transport, and watered prior to unloading on the project site. 5. Any portion of the site to be graded shall be pre- watered to a depth of three feet prior to the onset of grading activities. 6. Watering of the site or other soil stabilization method shall be employed on an on -going basis after the initiation of any grading activity on the site. Portions of the site that are actively being graded shall be watered regularly to ensure that a crust is formed on the ground surface, and shall be watered at the end of each work day. 7. Any area which will remain undeveloped for a period of more than 30 days shall be stabilized using either chemical stabilizers or a desert wildflower mix hydroseed on the affected portion of the site. 8. Landscaped areas shall be installed as soon as possible to reduce the potential for wind erosion. 9. SCAQMD Rule 403 shall be adhered to, insuring the clean -up of construction- related dirt on approach routes to the site. 10. All grading activities shall be suspended during first and second stage ozone episodes or when winds exceed 25 miles per hour. 11. The project proponent shall notify the City and SCAQMD of the start and end of grading activities in conformance and within the time frames established in the 2002 PM10 Management Plan. Applicable Previous Mitigation Measures The mitigation measures set forth above are comparable to and update those set forth in the Green EIR (SCH#94112047) and associated addendum. Additional mitigation measures set forth in previous approvals and to be applied to TTM No. 33444 include the following: 1. Construction access roads shall be paved as soon as is practicable following Engineering/Public Works department approval pf infrastructure plans and issuance of grading permits. Said roads shall be cleaned after each workday. The maximum vehicle speed limit on unpaved roads should be 15 mph. (EIR No. 7) 2. Architectural coatings and materials shall adhere to SCAQMD Rule 1113 or prevailing rule regarding volatile organic compounds. (EIR No. 10) 3. During the plan check review, the Engineering/Public Works and Building & Safety Departments shall consider the appropriateness of including bicycle lanes on Jefferson Street. (EIR No. 19) 4. Building design and construction shall conform to the state energy guidelines set forth in Title 24 of the California Administrative Code and other applicable codes and regulations. (EIR No. 21) 5. Prior to the issuance of building permits, consideration should be given to the use of solar water heaters and solar pool heaters. (EIR No. 23) -9- TN /City of La Quinta / Page 10 ' TTM 33444 EA/8.25.05 6. The project landscape plan shall optimize the potential for enhanced shading of sidewalks, parking areas and building walls to reduce solar gain. (EIR No. 25) ' Mitigation Monitoring and Reporting Prior to the issuance of grading permits, the City Building Department shall require, review and approve a detailed dust management plan consistent with the project grading plan. The dust control plan or equivalent ' documentation shall also address issues of construction vehicle staging and maintenance. Implementation of these mitigation measures will ensure that impacts associated with PM10 are mitigated to a less than significant level. -10- Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact IV. BIOLOGICAL RESOURCES -- Would the ro'ect: a) Have a substantial adverse effect, either X directly or through habitat modifications, on any species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service? b) Have a substantial adverse effect on any X riparian habitat or other sensitive natural community identified in local or regional plans, policies, regulations or by the California Department of Fish and Game or US Fish and Wildlife Service? c) Have a substantial adverse effect on X federally protected wetlands as defined by Section 404 of the Clean Water Act (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other means? d) Interfere substantially with the movement X of any native resident or migratory fish or. wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites? e) Conflict with any local policies or X ordinances protecting biological resources, such as a tree preservation policy or ordinance? f) Conflict with the provisions of an X adopted Habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan? -10- TN /City of La Quinta / Page 11 TTM 33444 EA/8.25.05 Sources: La Quinta General Plan and EIR, Green SP/TTM 33444 Biological Resources Assessment, ' AMEC Earth & Environmental, 2005; "General Biological Assessment Quarry Ranch," VHBC, Inc., June 2002; Coachella Valley Draft MSHCP & EIR/S ' Findings of Fact IV. a)- A biological resource analysis was prepared for the proposed project as part of the review of Tentative Tract Map 334442. The subject property is comprised of Sonoran creosote scrub and declining desert dry wash woodland (DDWW). The western two thirds of the 317.661 acre planning area is ' comprised of approximately 200 acres of creosote scrub located on slopes and piedmont formations; an intact and viable 12.29± acre desert dry wash in this portion. of the site extends north -south and drains to the north into the Quarry golf course off site. The northern most portion of this drainage has been impacted ' by adjacent off -site grading activities, which have encroached into the on -site portion of this drainage. The western area of TTM 33444 also borders the 12.5± acre parcel, portions of which are also comprised of DDWW, but which is predominantly creosote scrub; this parcel is not a part of the subject TTM 33444. ' The proposed residential subdivision area in the eastern portion of the subject property includes approximately 65 acres of DDWW habitat (actual acreage is approximately 56.72± acres based upon refined area calculations) and about 25 acres of creosote scrub habitat (adjusted number is approximately ' 22 acres). This site has also been impacted by hiking and off- highway vehicles (OHV) trails, as well as limited dumping of domestic trash and construction waste. ' The DDWW habitat in this area is characterized by the consulting biologist and CDFG staff as "declining (drought- stressed) ". As stated in the biology report prepared for TTM 33444, CDFG staff have indicated that this area of DDWW is not viable long -term habitat, and is in decline due to its isolation from essential upstream flows by the Devils Canyon diversion levees. The upstream levees have permanently isolated the ' subject property from storm flows from Devil's Canyon, which previously reached the site. To address DDWW issues, the CDFG has consulted with the applicant and has recommended that the project proponent file a Section 1602 Streambed Alteration Agreement (SSA) application applicable to the residential portion of this project and, which along with TTM 33444, is also the subject of this environmental assessment. Drainages associated with the SAA are small, limited in extent and located only on site. ' Sensitive Species: No sensitive wildlife or plant species were observed on the subject property during the most recent surveys. Sensitive plants with the potential to occur on site are limited to those with no state or federal designations. No sensitive plants proposed for protection under the Draft Coachella Valley MSHCP are expected to occur on the subject property. The DDWW is a "natural community" covered by the Draft MSHCP and the intact and viable 12.29± acres in the western portion of the subject property will remain undisturbed and protected in perpetuity. ' Sensitive wildlife species that have some potential occur on or near the subject property are limited to the following, which also indicates their probability of occurrence: Northern Red - diamond Rattlesnake (low probability), Prairie Falcon (moderate), Burrowing Owl (low), LeConte's Thrasher (low to moderate), ' Crissal Thrasher (moderate), Loggerhead Shrike (Occurs), Peninsular Bighorn Sheep (moderate), and Palm Springs Round - tailed Ground Squirrel (moderate). The site is not within the boundaries of the mitigation fee area of the Fringe -toed Lizard Habitat Conservation Plan. ' The assessment found that although the project occurs in the potential habitat area for several species of concern, the habitat on the project site has been degraded by off -road vehicle use and illegal dumping, and these species are not expected to occur on the site. A portion of the proposed project site has been graded as part of the construction on Tract 30651 (Quarry Ranch) since the preparation of the biological resource ' report, and is not expected to be habitat for any sensitive species at this time. ' 2 "General Biological Resources Assessment of the Green Specific Plan and tentative Tract Map No. 33444 ", Kajtaniak, David, Moorhatch, N., AMEC Earth & Environmental, Inc. March 30, 2005. -11- TN /City of La Quinta / Page 12 ' TTM 33444 EA/8.25.05 Draft Coachella Valley MSHCP: The Draft CV MSHCP is currently being reviewed following comments received from the general public, governmental agencies and other groups of interest; its adoption in ' advance of completion of review of TTM 33444 is not anticipated. Most of the mountainous western two- thirds of the subject property is located within the boundaries of proposed Conservation Areas (CAs) for the Coachella Valley Draft MSHCP, with the exception carved out for the aforementioned 12.5± acre ' residential site located adjacent to The Quarry and established in the Green Specific Plan. The Draft MSHCP CA boundary does include a limited portion'of the western margin of the proposed residential subdivision. Based upon consultation with CVAG and the US Fish and Wildlife Service ( USFWS), it is agreed that the toe of slope in this area was not drawn properly. The project proponent has met with CVAG, ' which has agreed that a map adjustment is justified conforming to the approximate toe of slope in this area (see attached exhibits and CV MSHCP). Based upon consultations with CVAG, CDFG and the USFWS, no conflicts with the Draft CVMSHCP are anticipated (see Exhibit C). Critical Habitat for Peninsular Bighorn Shee.: All of the western two -thirds and limited portions of the western and southern margins of the proposed residential subdivision is located within "critical habitat for Peninsular bighorn sheep (PBS) as delineated by the US Fish and Wildlife Service. All of five lots and I' portions of another five lots would occur within PBS critical habitat. The US Fish and Wildlife Service ( USFWS) has indicated that the boundaries of critical habitat are somewhat approximate due to the scale of the mapping effort. Based upon discussions with USFWS staff, impacts to sheep habitat may be mitigated ' through the dedication of the balance of the subject property (239± acres), which will be placed in permanent conservation. Based upon informal consultation with USFWS no additional mitigation has been requested. ' Mitigation Measures The Green Specific Plan provides significant mitigation for the development of the subject and 12.5± acre not -a -part site, which comprise the Green SP planning area. As a result of the Specific Plan and ' development mitigation, approximately 239 acres of the 331± Specific Plan site will be placed in permanent conservation, equating to a more than 2:1 on -site mitigation ratio. Nonetheless, specific mitigation measures should be applied to the approval of TTM 33444 to assure adequate mitigation. These include the following: A. Peninsular Bighorn Shee 1. In the event PBS are found to be attracted to the residential site, a three- person committee shall be formed, consisting of a representative of the Homeowners' Association (HOA), a representative of the California Department of Fish and Game (CDFG), and the Community Development Director. The purpose of the committee shall be to assess the need for a fence to keep Peninsular bighorn sheep from entering the project site. The committee shall monitor sheep activity through various means, including interviews with residents and visitors, and any available scientific data available and/or funded by the HOA. If bighorn sheep are seen on the project site, the committee shall require that the HOA, at its expense, construct an 8 foot fence along the property line between the project and the hillside. Gaps in the fence should be 11 centimeters or less. At the request of CDFG, temporary fencing may be required between the time that sheep are seen on the site and the time that permanent fencing is required. The committee shall exist for a period of 10 years, unless bighorn sheep are documented to no longer inhabit the Santa Rosa Mountains. At the end of 10 years, if any one member of the committee deems it necessary for the committee shall continue, until such time as it is dissolved by a unanimous vote of all its members. B. Desert Dry Wash Woodland The project grading plan shall be refined to limit disturbance to on -site DDWW to the greatest extent practicable. This shall be accomplished by careful staking and enforcing the limits of grading, establishing staging areas and routes of travel in already disturbed or first disturbed areas. Special attention shall be paid to preserving natural DDWW vegetation at and near the toe of slopes wherever possible. -12- TN /City of La Quinta / Page 13 TTM 33444 EA/8.25.05 2. To the extent practicable, on -site palo verde trees viable for use in project landscaping shall be boxed and maintained for later use within the project landscape plan. 3. The development of the residential subdivision shall include the provision of natural and re- naturalized perimeter and internal drainages enhanced with DDWW vegetation, in substantial conformance with the California Fish and Game Code Section 1602 Streambed Alteration Agreement being entered into between the project proponent and CDFG. 4. The project plant palette shall utilize native DDWW vegetation (palo verde, ironwood, smoketree, etc.) to the greatest extent practicable. Other native and drought - tolerant materials shall also be used. No invasive plant materials shall be permitted. A landscape palette consistent with these provisions shall be submitted to the project biologist and City for approval. C. Migratory Birds In order to comply with the federal Migratory Treaty Bird Act3 (MBTA), any vegetation or tree removal between February 1 and August 15`h shall require a qualified biologist to conduct at least one nesting bird survey, and more if deemed necessary by the consulting biologist, ending no less than three days prior to grading. In the event active nests are found, exclusionary fencing shall be placed 200 feet around the nest. D. Burrowing Owl Burrowing owls are know to occur within the project vicinity (Dike 4 south of Avenue 62), therefore, there is a low potential for this species to move onto the site in the future and prior to construction activities. Therefore, a qualified biologist shall conduct a clearance survey for burrowing owl immediately prior to commencement of ground- disturbing activities. Occupied burrows within development areas where development is proposed between February 1 and August 31 shall not be disturbed and shall be provided a 250 -foot buffer from development activities. In the event breeding pairs are found occupying burrows on site, off -site habitat shall be permanently protected by the applicant at the rate of 6.5 acres per breeding pair shall be protected through a conservation easement or other appropriate means, with the approval of CDFG (per CDFG Burrowing Owl directive letter of October 19 1995). Outside the breeding season and based upon consultation with CDFG, passive re- location of burrowing owls outside the breeding season may be accomplished through the installation of one -way doors in burrows. Mitigation Monitoring and Report The final subdivision map, final grading and drainage plans and landscape plans /palettes shall be reviewed by the City and project biologist for substantial conformance with the above cited mitigation measures. The applicant shall contribute funds sufficient to cover costs associated with this review. Said plans shall be approved prior to recordation of the final map. 2. Prior to the initiation of grading, the limits of grading shall be staked in the field and verified by the grading contractor. Large trees to be transplanted or boxed shall be identified and protected until moved. The applicant shall cover costs of the project biologists associated with complying with this measure. 3. Immediately prior to the commencement of grading or other site disturbance, the project biologist shall conduct MBTA - compliance surveys and report the results to the City and applicant. Any necessary protection shall be put in place prior to the initiation in the areas of potential impact. 4. Prior to the commencement of grading or other site disturbance, the project .biologist shall conduct clearance surveys for burrowing owls and report the results to the City and applicant. Any necessary protection shall be put in place prior to the initiation in the areas of potential impact. The MBTA (16 U.S.C. §§ 703 -712, July 3, 1918, as amended 1936, 1960, 1968, 1969, 1974, 1978, 1986 and 1989). -13- TN /City of La Quinta / Page 14 TTM 33444 EA/8.25.05 Prior to the issuance of grading permits, the applicant shall provide the City with a fully executed copy of a Streambed Alteration Agreement for the TT M 33444 project, unless it is determined that the project does not require such a permit. Applicable Previous Mitigation Measures The mitigation measures set forth above are comparable to and update those set forth in the Green EIR (SCH#94112047) and associated addendum. Additional mitigation measures set forth in previous approvals and to be applied to TTM No. 33444 include the following: 1. To the greatest extent practicable, the applicant shall ensure that individual barrel cactus, ocotillo, mesquites, acacias, palo verde and other native trees and plants shall be salvaged from the areas to be graded, placed in an on -site nursery prior to the issuance of grading permits, and integrated into project landscaping prior to the issuance of occupancy permits. (EIR No. 2) 2. The project CC &Rs shall include provisions which prohibit free roaming pets, including but not limited to dogs and cats, which shall be kept on a leash when off the individual lot on which the pet resides. (EIR No. 3) Sources: Travertine and Green Specific Plans, Final EIR and associated Cultural Resources Survey and Report prepared by Paul G. Chace, Ph.D., The Keith Companies. July 1994; La Quinta General Plan and EIR. Findings of Fact V. a)_ J The subject property occurs within an area influenced by the periodic inundation of the Coachella Valley's Salton Sink by the Colorado River, providing important resources for native peoples. A wide range of archaeological resources have been identified in the project vicinity, especially along the ancient shoreline of Lake Cahuilla. It is likely that the Green Specific plan site was visited and utilized for gathering and hunting by local peoples in prehistoric times. However, surveys indicate that the site was never intensely utilized and no archaeological sites nor historical landmarks are evident today, although evidence of past use may have been obliterated by erosion. One off -site archaeological site was detected (isolated bedrock milling station). The site was recorded (RIV -5324) and filed with the State's California Archaeological Inventory per P.R.C. 21083.2. Consultation with the Torres - Martinez Tribe resulting in no reporting of archeological or historical landmarks. -14- Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact V. CULTURAL RESOURCES -- Would the project: a) Cause a substantial adverse change in X. the significance of a historical resource as defined in '15064.5? b) Cause a substantial adverse change in X the significance of an archaeological resource pursuant to '15064.5? c) Directly or indirectly destroy a unique X paleontological resource or site or unique geologic feature? d) Disturb any human remains, including X those interred outside of formal cemeteries? Sources: Travertine and Green Specific Plans, Final EIR and associated Cultural Resources Survey and Report prepared by Paul G. Chace, Ph.D., The Keith Companies. July 1994; La Quinta General Plan and EIR. Findings of Fact V. a)_ J The subject property occurs within an area influenced by the periodic inundation of the Coachella Valley's Salton Sink by the Colorado River, providing important resources for native peoples. A wide range of archaeological resources have been identified in the project vicinity, especially along the ancient shoreline of Lake Cahuilla. It is likely that the Green Specific plan site was visited and utilized for gathering and hunting by local peoples in prehistoric times. However, surveys indicate that the site was never intensely utilized and no archaeological sites nor historical landmarks are evident today, although evidence of past use may have been obliterated by erosion. One off -site archaeological site was detected (isolated bedrock milling station). The site was recorded (RIV -5324) and filed with the State's California Archaeological Inventory per P.R.C. 21083.2. Consultation with the Torres - Martinez Tribe resulting in no reporting of archeological or historical landmarks. -14- TN /City of La Quinta / Page 15 TTM 33444 EA/8.25.05 The Green Specific Plan EIR concluded that neither archaeological nor historical resources were found on the subject property, and that no further specific planning considerations were warranted. Given the number of recorded archaeological sites in the vicinity, the planning area should be considered "sensitive" and as having the potential for such resources to be uncovered during site grading. The site lies above the high water (approximately 42 feet) mark for the numerous stands of ancient Lake Cahuilla and does not harbor bi -valves or other paleontological resources associated with the lake. Mitigation Measures Based upon earlier project - specific reports and the Specific Plan EIR, the following mitigation is required: 1. , A trained archaeological monitor shall be present on and off site during all grubbing and earth ' moving activities, and shall be empowered by the grading and/or general contractor to halt or redirect grading activity when necessary to protect potential archaeological resources. Mitigation Monitoring and Reporting The monitor shall be required to submit to the Community Development Department, for review and approval, a written report on all activities on the site prior to occupancy of the first building on the site. -15- Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact VI: GEOLOGY AND SOILS -- Would the project: a) Expose people or structures to potential X substantial adverse effects, including the risk of loss, injury, or death involving: i) Rupture of a known earthquake fault, as X delineated on the most recent Alquist- Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault ii) Strong seismic ground shaking? X iii) Seismic - related ground failure, X including liquefaction iv) Landslides? X b) Result in substantial soil erosion or the X loss of topsoil? d) Be located on expansive soil, as defined X in Table 18 -1 -B of the Uniform Building Code (1994), creating substantial risks to life or property e) Have soils incapable of adequately X supporting the use of septic tanks or alternative waste water disposal systems where sewers are not available for the disposal of waste water? -15- TN /City of La Quinta / Page 16 TTM 33444 EA/8.25.05 Sources: Travertine and Green Specific Plans EIR, July 1994; La Quinta General Plan and EIR; Geotechnical Investigation/Green property, Sladden Engineering, January 2005; Geotechnical Investigation Report/Slope Stability, Sladden Engineering, May 18, 2005; US Soils Survey for Coachella Valley, 1979. Findings of Fact Soils: A geotechnical analysis was completed for the project site as part of the review of Tentative Tract Map 33444°. On -site soils are comprised of the Carsitas - Myoma - Carrizo soil association and are characterized by nearly level to steep, somewhat excessively drained or excessively drained sands, fine sands, gravelly sands, cobbly sands, and stony sands on alluvial fans and valley fill. Each of these conditions can be found on the subject 317.66± acre property. Portions of the site are also identified as "rocky outcrop -Lithic Torripsamments association, characterized as strongly sloping to very steep with well- drained sandy soils. The residential portion of TTM 33444 is underlain primarily by Carsitas gravely sand. The development area, which is located along the margins of rocky outcrop and valley fill areas, are especially vulnerable to seismically- induced settlement. The soils within the residential subdivision area have a generally "very low" expansion capacity. Ground water is expected to occur at a depth of 100 -feet or greater, therefore the site has a low susceptibility to liquefaction. Soils are suitable for the proposed use with proper site preparation. Seismicity: The project property is located approximately 9 miles southwest of the San Andreas Fault and is within a Zone III groundshaking zone. The property is not located within an Alquist Priolo Fault Hazard Study Zone and no active faulting is expected to occur on site. The property, as with the rest of the City, will be subject to significant ground movement in the event of a major earthquake, with potential ground acceleration ranging from 0.26 to 0.31g during a major nearby quake. Structures on the site will be required to meet the City's and the State's standards for construction, which include Uniform Building Code requirements for seismic zones. These requirement will ensure that impacts from ground shaking are reduced to a less than significant level. Soils Erosion: The site is not located in a blowsand hazard area, and will therefore not be subject to significant soil erosion from wind. The site is subject to limited flooding erosion, however, most of this potential is located outside the proposed residential subdivision. The developer will be required to secure approval of drainage facilities from the City, Coachella Valley Water District and the US Bureau of Reclamation for flood control improvements needed to protect the subject and surrounding properties the site. The developer's plans include stable channels and sedimentation basins, which will also serve to control of soil erosion. Please also see hydrology discussion below. Slopes and Hillside Conservation: Portions of the proposed residential subdivision are located adjacent or encroaching into areas with slope in excess of 20 %, some of which also show signs of instability and sloughing. Other areas of the proposed subdivision are located adjacent to rocky outcroppings some of which are highly fractured and may include perched rock subject to dislocation in a strong seismic event. A slope stability analysis5 was conducted to assess this hazard and concluded that "some surface boulders ands cobbles may be susceptible to downslope movement resulting from erosion or seismic events ". The slope stability analysis has determined that the proposed design of the residential subdivision, including the construction of drainage swales and conservation buffers along the base of the hillsides, "should adequately mitigate rockfall or rolling boulder hazards." The supplemental slope analyses on proposed engineered slopes "suggest that the proposed engineered slopes to be constructed at a 2:1 (horizontal to vertical) slope angle should be stable." Approximately four small isolated hills, which are separated from nearby rocky outcroppings by shallow ' alluvial fill, are located within the bounds of the project development area. Three of the four outcroppings are essentially preserved by their delineation as protected areas. The fourth is located within the neck and cul -de -sac of Lot F and will be removed to provide for this road improvement. The protection of one hillside /outcropping area located on the east side of Jefferson Street is protected by a minor adjustment of the Jefferson Street right -of -way to the west. ' 4 "Geotechnical Investigation of a Residential Subdivision -Green Property", Sladden Engineering, January 2005. 5 Supplemental Geotechnical Analysis prepared by Sladden Engineering, May 18, 2005. -16- 1 TN /City of La Quinta / Page 17 TTM 33444 EA/8.25.05 Mitigation Measures Mitigation measures were adopted for the Green Specific Plan, which provided general prescriptions addressing soils and erosion, seismic /slope stability, and liquefaction, and are herein incorporated by reference and as set forth below. The final map shall conform to and reflect the recommendations of the slope stability investigation prepared for TTM No. 33444. The City Engineer shall assure that required provisions are incorporated in project grading and other development plans. 2. The seismic provisions included in the Uniform Building Code for Seismic Zone 4 shall be considered the minimum design criteria for the residential portions of the TTM 33444 planning area. 3. The Final Map shall conform to the approved slope analysis prepared for this project and shall conform to Sections 9.110.070 and 9.140.040 of the City Municipal Code. 4. The Final Map shall assure the protection of surrounding hillside and the isolated rock outcroppings located in the southern and southwest portion of the subject subdivision, as depicted on the tentative tract map. Applicable Previous Mitigation Measures The mitigation measures set forth above are comparable to and update those set forth in the Green EIR (SCH#94112047) and associated addendum. Additional mitigation measures set forth in previous approvals and to be applied to TTM No. 33444 include the following: 1. The loss of soils through wind or water erosion shall be minimized to the greatest extent practicable through conservation of native vegetation, use of permeable ground covers and materials, careful regulation of grading practices, and the application of soil stabilizers. (EIR No.s 1 & 2) 2. Appropriate geotechnical monitoring of grading, trenching, ripping, blasting and other site disturbing activities shall be conducted and the need for design modifications resulting from unanticipated site conditions shall be reviewed and approved by the City Engineer prior to their undertaking. (EIR No. 8) Mitigation Monitoring and Reporting 1. A final geotechnical report and appropriate subdivision design details addressing slope stability and other additional issues identified by the City Engineer shall be approved by the City Engineer prior to the recordation of the final map or issuance of grading plans, whichever occurs first. If necessary, the subdivision map shall, through changes in lot design, setbacks or other means, incorporate the recommendations set forth in the final geotechnical report. 2 Monitoring of site grading or blasting, trenching and comparable development activities shall be monitored by a qualified geological engineer as required in the final geotechnical report for TTM 33444. -17- Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact VII. HAZARDS AND HAZARDOUS MATERIALS - -Would the project: a) Create a significant hazard to the public X or the environment through the routine transport, use, or disposal of hazardous materials? -17- TN /City of La Quinta / Page 18 TTM 33444 EA/8.25.05 b) Create a significant hazard to the public X or the environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment? c) Emit hazardous emissions or handle X hazardous or acutely hazardous materials, substances, or waste within one - quarter mile of an existing or proposed school? d) Be located on a site which is included X on a list of hazardous materials sites compiled pursuant to Government Code Section 65962.5 and, as a result, would it create a significant hazard to the public or the environment? e) For a project located within an airport X land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project result in a safety hazard for people residing or working in the area? f) For a project within the vicinity of a X private airstrip, would the project result in a safety hazard for people residing or working in the project area? g) Impair implementation of or physically X interfere with an adopted emergency response or evacuation plan? h) Expose people or structures to a X significant risk of loss, injury or death involving wildland fires, including where wildlands are adjacent to urbanized areas or where residences are intermixed with wildlands? (General Plan land use map) Sources: Travertine and Green Specific Plans EIR, July 1994; TTM 33444 application; La Quinta General Plan and EIR; Riverside County General Plan, 2003. Findings of Fact VII. a) -h) The construction of residential units on the proposed project site will not result in significant impacts associated with hazardous materials. Neither is the project expected to impair the implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan. Provision is made for emergency secondary access for the subject subdivision, which will also facilitate the extension of the future Jefferson Street realignment to the south. The City implements the standards of the Household Hazardous Waste programs through its waste provider. These regulations and standards ensure that impacts to surrounding areas, or within the project itself, are less than significant. The site and surrounding mountains are characterized by low- density vegetation and fuel loads; the site is in an area subject to a "low" wildland fires hazard (Riverside County General Plan, Wildfire Susceptibility map, Fig. S -11. 2003). -18- . 1 TN /City of La Quinta / Page 19 TTM 33444 EA/8.25.05 Mitigation Measures No mitigation measures required. ' Mitigation Monitoring and Reporting No specific monitoring or reporting required. on; La Quinta General Plan and EIR; Coral Mountain Hydrology Analysis /Plan, Pacific Advanced Civil Engineering, April -19- Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact VIII. HYDROLOGY AND WATER QUALITY -- Would the project: a) Violate any water quality standards or X waste discharge requirements? b) Substantially deplete groundwater supplies or interfere substantially with X groundwater recharge such that there would be a net deficit in aquifer volume or a lowering of the local groundwater table level (e.g., the production rate of pre - existing nearby wells would drop to a level which would not support existing land uses or planned uses for which permits have been anted)? c) Substantially alter the existing drainage pattern of the site or area, including through X the alteration of the course of a stream or river, in a manner resulting in substantial erosion or siltation on- or off -site? d) Substantially alter the existing drainage X pattern of the site or area, including through the alteration of the course of a stream or river, or substantially increase the rate or amount of surface runoff in a manner that would result in flooding on- or off -site? e) Create or contribute runoff water which X would exceed the capacity of existing or planned stormwater drainage systems or provide substantial additional sources of polluted runoff`? f) Place housing within a 100 -year flood X hazard area as mapped on a federal Flood Hazard Boundary or Flood Insurance Rate Map or other flood hazard delineation map? g) Place within a 100 -year flood hazard area X structures, which would impede or redirect flood flows? Travertine d G if Sources: rave ne an reen Specific is Plans EIR, July 1994; TTM 33444 applicati on; La Quinta General Plan and EIR; Coral Mountain Hydrology Analysis /Plan, Pacific Advanced Civil Engineering, April -19- TN /City of La Quinta / Page 20 TTM 33444 EA/8.25.05 2005 /Revised August 3, 2005; Hydrology & Drainage Concept Study for Quarry Ranch, Tettemer and Assoc., July 2002. Findings of Fact VIII. a) — d)) Water Resources The proposed development will encompass approximately 78.78 acres, of which approximately 53 acres will consist of residential lots. Applying the Coachella Valley Water District's (CVWD) net (post -return flow) domestic water demand ratio of 3.96 acre -feet per acre of low density residential per year, the proposed subdivision will generate a potential demand for up to 210 acre -feet per year. The development guidelines for the project include the extensive use of native desert and other drought- tolerant vegetation, which could significantly reduce the project's overall demand for water. The project and other land uses in the subbasin serving this area have been analysed in the CVWD Water Management Plan, which helps to assure that the proposed and comparable development will not be a significant contributor to the depletion of groundwater supplies. The Coachella Valley Water District provides domestic water to the subject property. The 219 homes will be required to implement the City's standards for water conserving plumbing fixtures and on -site retention, which both aid in reducing the potential impacts to groundwater. The proposed project will also meet the requirements of the City's water - conserving landscaping ordinance. These standards will reduce potential impacts to a less than significant level. The project will not interfere with groundwater recharge. The project will not violate any water quality standards or waste discharge requirements, being required to connect to a community waste collection and treatment system. Flooding and Hydrology The proposed project will be responsible for the drainage of on and off -site flows tributary to the Bureau of Reclamation Dike No. 2. Siltation and debris were identified as issues of concern in this area, due to its proximity to the Coral Reef Mountains. The proposed project will tie into the improvements for Tentative Tract Map 30651, which include an earthen ditch with flood wall at the south boundary of the adjacent (Quarry Ranch) tract. The City and CV WD required the preparation of a hydraulics, hydrology and drainage study6 for Tentative Tract Map 33444, to address flood control issues throughout the site, which has been used for this assessment. The watershed was divided into three subareas and are included in or related to the TTM 33444 project and were evaluated in the most recent PACE hydrology analysis. The watershed in which the residential portion of the project is located is limited to 0.44 square miles and is defined by the Devil's Canyon/Guadalupe diversion levee to the south, the top of elevated on -site terrain to the west and the ridgeline of Coral Mountain on the east. The subject property drains to the north with on -site drainage currently intercepted by the aforementioned diversion along and within the ownership of Quarry Ranch. This drainage is then discharged at the northeast corner of the subject property and into the stormwater impound area created by the Bureau of Reclamation (USBR) Dike No. 2. TTM 33444 is part of a larger 2,390± acre drainage area that generates a combined SPF volume of approximately 951 acre -feet, approximately 464 acre -feet of which is routed to and captured by the Dike 4 impound. Dike 4 has a small outlet to the Lake Cahuilla terminal lake impound area and has no subsequent outlet. The Dike 2 impound was analysed in 1993 by The Keith Companies in 1993 for The Quarry project, again in 2002 by Tettemer for the Quarry Ranch development and once again by PACE for the subject development. The Dike 2 levee is approximately 5,000 feet long and 20 -feet high with a resulting retention basin capacity of 700± acre -feet. The Quarry development has incorporated 500 acre -feet of on -site retention, which captures all of the approximately 430 acre -feet of SPF storm runoff. In conjunction with existing on -site retention of 500 acre -feet located within The Quarry, the Dike 2 impound appears to have ample capacity to safely store watershed runoff from a 100 -year and Standard Project Flood (SPF) event. �1 6 "Coral Canyon Environmental Assessment Hydrology ", Mark E. Krebs, P.E., Pacific Advanced Civil Engineering, Inc. April 2005, Revised August 3, 2005. -20- TN /City of La Quinta / Page 21 TTM 33444 EA/8.25.05 As noted above, the southern portion of the Dike 2 drainage area is defined by the Devil Canyon (Guadalupe) Training Dike, which protects the eastern portion of Section 29 and the residential development site from storm flows from the 12.5± square mile Devil Canyon watershed. Prior to the dike's construction, Devil Canyon flows may have occasionally found their way through this area. Preliminary analysis of the Devil Canyon training dike indicates that it effectively precludes Devil Canyon discharge from reaching the subject property. Studies to certify the Devils Canyon training dike, including geotechnical, hydraulic capacity and slopes stability analyses, are underway and will be included with a Conditional Letter of Map Amendment (CLOMR) application to be filed with the Federal Emergency Preparedness Agency (FEMA). The Keith Companies' 2002 Quarry Report Drainage Analysis provided preliminary Training Dike evaluation and determined that the facility is competent and satisfactorily conveys the standard project flood (SPF) Devil Canyon watershed flows without over - topping or eroding the Training Dike, thus protecting the TTM 33444 project site from the Devil Canyon flows. Proposed Drainage Improvements: Drainage facilities for TTM 33444 include the integration of the existing Quarry Ranch diversion channel located immediately north of the subject property. This existing facility will be improved to provide a 15 -foot channel bottom with a design flow depth of 3 -feet (see Section XS2 in PACE hydrology report). Upstream improvements include a combination of roads, pipes or culvert, and dedicated surface channels that will double as enhanced open space. The largest channel will provide bottom width of approximately 20 -feet, and will include a soft bottom as well as strategically placed concrete and rock revetment to prevent erosion. Smaller channels are designed to occur at the foot of slopes and convey limited runoff around residences and into larger drainages. The design also includes four on- site debris and detention basins. Final design of channels and detention basins will need to balance functionality with other project goals, including habitat enhancement and accessibility as open space. VIII. f & g) The site is not located in a flood zone as designated by FEMA and as such is considered to be in an area potentially susceptible to an uncharacterized flooding hazard. As a condition of approval, the applicant should be required to secure recognition of the Devil Canyon Training Dike and a Conditional Letter of Map Revision (CLOMR) from FEMA. Mitigation Measures Prior to the issuance of grading permits, the developer shall prepare and submit a final drainage analysis, as well as detailed geotechnical and storage volume analyses, of Dike 2 to CVWD for review and approval. Said plans shall be consistent with the habitat enhancement requirements of the Coral Canyon 1602 Streambed Alteration Agreement and the provision of accessible open space within on- site drainage facilities. 2. Prior to the issuance of grading permits, the developer shall prepare and submit a final drainage analysis, as well as detailed geotechnical and storage volume analyses, of the Devil Canyon Training Dike to CVWD for review and approval. 3. In the event the City or CVWD accepts and approves the Devil Canyon Training Dike, prior to the issuance of the first occupancy permit the developer shall secure certification of the levee and a Conditional Letter of Map Revision (CLOMR) from the Federal Emergency Management Agency (FEMA). Unless and until the subject dike is accepted and /or certified, residents of the subdivision shall be required to secure flood hazard insurance from FEMA. 4. Prior to recordation of the. Final Map or issuance of grading permits, whichever comes first, and in conjunction with City input and review, CVWD and /or USBR will review and approve off -site drainage facilities as they pertain to impacts to the Dike 2 impound and levee to facilitate project access and to complete area -wide drainage facilities. "Coral Canyon Environmental Assessment Hydrology ", Mark E. Krebs, P.E., Pacific Advanced Civil Engineering, Inc. April 2005, Revised August 3, 2005. -21- � I � I � I � I � I TN /City of La Quinta / Page 22 TTM 33444 EA/8.25.05 5. The landscape palette for the development, including that to which residents shall be limited, shall incorporate native and other drought - tolerant plant materials to the greatest extent practicable. No invasive plants, as identified by the City and/or the Coachella Valley Mountains Conservancy, shall be permitted and residents shall be provided a landscape materials guide with the sale of each home. Applicable Previous Mitigation Measures The mitigation measures set forth above are comparable to and update those set forth in the Green EIR (SCH#94112047) and associated addendum. Additional mitigation measures set forth in previous approvals and to be applied to TTM No. 33444 include the following: � I � I � I � I � I All public and private street rights -of -way shall be designed so as to avoid nuisance water ponding and the production of insects. The Engineering /Public Works Department shall review and approve all future public and private street rights -of -way prior to Final Map approval. (EIR No. 4) Notes on construction plans shall incorporate all Best Management Practices adopted by the Engineering /Public Works Department, prior to issuance of grading permits. (EIR No. 6) Mitigation Monitoring and Reporting Final on -site drainage facilities plans shall be reviewed and approved by the City Engineer and the CVWD prior to the recordation of the final map or the issuance of grading permits. The City Engineer shall regularly monitor grading and drainage construction activities and assure that on -site improvements are construction in conformance with approved plans. 2. Prior to the issuance of the first occupancy permit, the applicant shall provide documentation in the form of a letter or conditional letter of map revision from FEMA demonstrating that the residential subdivision occurs outside a 100 -year flood zone. 3. Prior to the approval of the Final Map or the issuance of grading permits, whichever occurs first, the applicant shall provide proof of approval from CVWD (and as necessary USBR) to encroach into and conduct grading and other activities facilitating the implementation of the project drainage plan, as well as the construction of Jefferson Street across CVWD and USBR lands and easements. I 4. Prior to the issuance of grading permits, the applicant shall submit detailed landscaping plans and palettes to and shall secure approval from the City Community Development Department. -22- Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact IX. LAND USE AND PLANNING - Would the project: a) Physically divide an established X .community? b) Conflict with any applicable land use X plan, policy, or regulation of an agency with jurisdiction over the project (including, but not limited to the general plan, specific plan, local coastal program, or zoning ordinance) adopted for the purpose of avoiding or mitigating an environmental effect? -22- TN /City of La Quinta / Page 23 TTM 33444 EA/8.25.05 c) Conflict with any applicable habitat X conservation plan or natural community conservation plan? Sources: Green Specific Plan and EIR; La Quints General Plan, 2002; TTM 33444; Site Surveys. Findings of fact IX. a -c The proposed subdivision will not divide an existing community but rather may facilitate the interconnectivity of existing and future planned development in the vicinity through the extension of Jefferson Street. The proposed tract map is consistent with the General Plan designation of LDR (Low Density Residential and Zoning (Low Density Residential). Earlier versions of the proposed track did not conform to the City hillside conservation ordinances. However, the current version of the subdivision map has eliminated or adequately modified these areas of conflict and the subdivision does now appear to conform to the subject ordinances. Stranded outcroppings are also protected by the minor realignment of Jefferson Street and the delineation and protection of the isolated outcroppings within residential lots. A small outcropping is impacted by the extension of the Lot F cul -de -sac and is determined to be less than significant. The development of housing on the subject property represents a continuation of comparable existing and planned development, with The Quarry and Quarry Ranch contiguous to the site, and the approved Travertine project located a short distance to the south and connected by the future General Plan road Jefferson Street. Green Specific Plan As noted, TTM 33444 implements certain development provisions of the Green Specific Plan, as amended. The tract does not address or otherwise effect the 12.5 acre residential parcel (Parcel 3 of PM 28617) located contiguous to The Quarry and with direct access. to that project's internal road system. The proposed tract map would convert Lot `B" of PM 28617 (Liberty Lane) to a common open space lot (Lot "BBB" TTM 33444), and also convert the eastern segment of this road lot for drainage management and open space. The proposed tract map does not affect the development potential of any portion of the site but does lessen the extent and intensity of site development on the property with the conversion of Liberty Lane to open space. The current Green Specific Plan provides for the development of up to 267 single - family homes on the eastern residential development site. The proposed project of 219 lots is a 17.6% reduction in density in this area. The Specific Plan provides for up to 227 lots of min. 8,000 s.f. and 40 lots of min. 10,000 s.f. TTM 33444 provides 74 lots of 8,000 to 10,000 s.f. and 145 lots of 10,000 s.f. and larger. Overall, the subdivision facilitates the goals and objectives of the Specific Plan by providing lower density, more estate lots and enhanced open space. Total open space lands outside the residential portion of the project totals 225.54± acres. Within TTM 33444, 20.82± acres of open space is provided and includes landscape areas and enhanced and accessible drainages areas. In addition, a 0.85 acre recreation area with community facilities; pool and spa, and health club are provided in the subdivision. Therefore, open space provided by TTM 33444 both within and outside the residential subdivision provides a total of 247.21 acres of natural and enhanced open space, or a 6.9% increase over that set forth in the Specific Plan. The Green Specific Plan makes provision for development in Open Space areas of the plan in strict conformance with the City's hillside conservation ordinances. Relevant to this issue is the dedication of drainage and open space easements within the residential development area and not counted in the 225.54 acres of other open space. The subdivision substantially conforms to the development standards and regulations set forth in the Specific Plan for "Estate Lots /Min. 10,000 s.f.) and "Cove Lots" (min. 8,000 s.f.). To assure conformance with the Green Specific Plan, residences on each lot shall provide a minimum livable space of 2,200 s.f. The site is not within the boundaries of the Coachella Valley Fringe -toed Lizard Habitat Conservation Plan fee area. Western portions of the proposed residential development are located within the proposed boundaries of the Santa Rosa and San Jacinto Mountains Conservation Area (SRSJM CA) as currently delineated in the Coachella Valley Multiple Species Habitat Conservation Plan ( MSHCP). Consultation ' between the applicant and the MSHCP proponent has indicated that a boundary adjustment to better reflect -23- TN /City of La Quinta / Page 24 TTM 33444 EA/8.25.05 actual conditions and topography shall be considered, which would bring the proposed subdivision into conformance with the future adopted MSHCP (please also see biology discussion above). Mitigation Measures 1. All residences shall provide a minimum of 2,200 s.f. of livable space in accordance with the Specific Plan. 2. Isolated rock outcroppings delineated on Tentative Tract Map 33444 and part of lots 150, 152, 153, 154, 170, 171 and 172 shall be shall be delineated as non - disturbance areas on the Final Map and grading plans. Mitigation Monitoring and Reporting Prior to the issuance of residential building permits, the Community Development Department shall review the building plans for project residences and assure the provision of a minimal livable space of 2,200 square feet. 2. Prior to recordation of the Final Map and issuance of grading permits, the Community Development Department and the Building and Safety Department shall review the Final Map and grading plans to assure that the isolated rock outcroppings shown on Tentative Tract Map 33444 and part of lots 150, 152, 153, 154, 170, 171 and 172 are delineated as non - disturbance areas. Sources: Green Specific Plan and EIR; La Quinta General Plan, 2002; TTM 33444; Site Surveys. Findings of Fact Aggregate resources in the Coachella Valley were evaluated by the California Department of Conservation, Division of Mines and Geology (DMG), now known as the California Geological Survey, (CGS) in a 1988 report entitled, "Aggryate Land Classification: Aggregate Materials in the Palm Springs Production - Consumption Region" . The proposed project site is .within the MRZ -3 Zone, which includes "Areas containing mineral deposits, the significance of which cannot be evaluated from available data. MRZ -3 includes lands composed of Cabazon Fanglomerate, Ocotillo Conglomerate, Painted Hills Formation, Palm Springs Formation, Mecca Formation, and metamorphic rocks of the San Jacinto Mountains and the San Gorgonio Complex. The subject property is located in proximity to the County quarry that was retired and converted to The Quarry golf course community. The site may harbor viable sand and gravel resources. 8 "Mineral Land Classification: Aggregate Materials in the Palm Springs Production- Consumption Region.," prepared by the California Department of Conservation Division of Mines and Geology, 1988. -24- Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact X. MINERAL RESOURCES -- Would the project: a) Result in the loss of availability of a X known mineral resource that would be of value to the region and the residents of the state? b) Result in the loss of availability of a X locally- important mineral resource recovery site delineated on a local general plan, specific plan-or other land use plan? Sources: Green Specific Plan and EIR; La Quinta General Plan, 2002; TTM 33444; Site Surveys. Findings of Fact Aggregate resources in the Coachella Valley were evaluated by the California Department of Conservation, Division of Mines and Geology (DMG), now known as the California Geological Survey, (CGS) in a 1988 report entitled, "Aggryate Land Classification: Aggregate Materials in the Palm Springs Production - Consumption Region" . The proposed project site is .within the MRZ -3 Zone, which includes "Areas containing mineral deposits, the significance of which cannot be evaluated from available data. MRZ -3 includes lands composed of Cabazon Fanglomerate, Ocotillo Conglomerate, Painted Hills Formation, Palm Springs Formation, Mecca Formation, and metamorphic rocks of the San Jacinto Mountains and the San Gorgonio Complex. The subject property is located in proximity to the County quarry that was retired and converted to The Quarry golf course community. The site may harbor viable sand and gravel resources. 8 "Mineral Land Classification: Aggregate Materials in the Palm Springs Production- Consumption Region.," prepared by the California Department of Conservation Division of Mines and Geology, 1988. -24- TN /City of La Quinta / Page 25 ' TTM 33444 EA/8.25.05 I Current permitted sand and gravel reserves in the Valley are estimated at 236.8 million tons (based on Riverside County and BLM permit files) on both public and private land. Approximately 10% of the total is ' located on public land managed by the BLM, with the remainder on private land. The 236.8 million tons of permitted reserves is a significant increase over the 1985 permitted reserve figure of 67 million tons; and is due to recent permit approvals of a large, new mine on the Fargo Canyon alluvial fan near Indio, significant expansion of an existing mine in the Indio Hills also near Indio, and permitting of a number of smaller ' operations in Thousand Palms and west Berdoo Canyon. Total aggregate production during 2001 in the Coachella Valley was approximately 2 million tons, of which approximately 661,000 tons were mined on BLM land. Based upon the depth of permitted reserves, the loss of possible access to on -site mineral resources is less than significant. Mitigation Measures ' None required. Mitigation Monitoring and Reporting None required. "_4 Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact M. NOISE Would the project result in: a) Exposure of persons to or generation of X noise levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies? b) Exposure of persons to or generation X of excessive groundborne vibration or groundboine noise levels? c) A substantial permanent increase in X ambient noise levels in the project vicinity above levels existing without the project? d) A substantial temporary or periodic X increase in ambient noise levels in the project vicinity above levels existing without the project? e) For a project located within an airport X land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive noise levels? f) For a project within the vicinity of a X private airstrip, would the project expose people residing or working in the project area to excessive noise levels? "_4 TN /City of La Quinta / Page 26 TTM 33444 EA/8.25.05 Sources: La Quinta General Plan and EIR; Green Specific plan and EIR; Urban Crossroads Traffic Analysis, 2005. Findings of fact The project site is not located in an area of the City subject to high traffic noise levels. The project site is not within the vicinity of an airport or airstrip. Impacts associated with noise on or near the project site are not expected to be significant. The location of single - family homes on the site will not generate significant noise levels. The impacts associated with long -term noise are not expected to be significant. The construction of the project will generate noise from site grading, possible blasting, and from other construction equipment and activities. Existing homes occur to the north of the site and will be buffered to a substantially degree by an existing block wall and internal street in the Quarry Ranch development. Homes are considered sensitive receptors to noise, and the construction at the site could have a negative , if limited, impact on nearby residences. Mitigation Measures In order to reduce these potential impacts, the following mitigation measures shall be implemented: 1. All internal combustion equipment operating on the subject property shall be fitted with properly operating mufflers and air intake silencers. 2. All stationary construction equipment (e.g. generators and compressors) shall be located as far away from existing homes and other sensitive receptors as possible. 3. Construction activities shall be limited to the hours prescribed in the La Quinta Municipal Code. Applicable Previous Mitigation Measures ' The mitigation measures set forth above are comparable to and update those set forth in the Green EIR (SCH #94112047) and associated addendum. Additional mitigation measures set forth in previous approvals and to be applied to TTM No. 33444 include the following: ' 1. Construction activities on -site should take place only during the days and hours specified by City Ordinance to reduce noise impacts during more sensitive time periods. (EIR No. 1) ' 2. With the issuance of grading and building permits, stockpiling and vehicle staging areas shall be located as far as practicable from homes and other noise sensitive receptors during construction activities. (EIR No. 4) ' 3. Building setbacks, pad elevations, landscape berms and/or masonry walls shall be integrated into the project's design to reduce the effects of traffic noise along Jefferson Street to assure compliance with the City Noise Ordinance. (EIR No.s 6 & 7) ' Mitigation Monitoring and Reporting The City shall review the project grading plans and assure that stationary noise sources, as well as ' equipment maintenance and staging areas sources are located sufficiently away from existing residences. City inspectors, as well as the grading and general contractors, shall regularly monitor construction operations and associated noise generation near residences. MI. POPULATION AND HOUSING = Would the project: Potentially Less Than Less Than Significant Significant w/ Significant Impact Mitigation I Impact No Impact TN /City of La Quinta / Page 27 TTM 33444 EA/8.25.05 a) Induce substantial population growth in Potentially Less Than X No an area, either directly (for example, by Significant Significant w/ Significant Impact proposing new homes and businesses) or Impact Mitigation Impact indirectly (for example, through extension of roads or other infrastructure)? b) Displace substantial numbers of X existing housing, necessitating the construction of replacement housing elsewhere? c) Displace substantial numbers of people, X necessitating the construction of replacement housing elsewhere? Sources: La Quinta General Plan and EIR; Green Specific plan and EIR; TTM 33444. Findings of Fact The proposed project is consistent with the General Plan land use designation and zoning designation for the property, and is in an area designated for low and density residential land uses. The project will not significantly induce growth or displace an existing community. Mitigation Measures None required. Mitigation Monitoring and Reporting None required. Sources: La Quinta General Plan and EIR; Green Specific Plan and EIR; TTM 33444. -27- Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact XIII. PUBLIC SERVICES a) Would the project result in substantial adverse physical impacts associated with the provision of new or physically altered .governmental facilities, need for new or .physically altered governmental facilities, the construction of which could cause significant environmental impacts, in order to maintain acceptable service ratios, response times or other performance objectives for any of the public services: Fire protection? X Police protection? X Schools? X Parks? X Other public facilities? X Sources: La Quinta General Plan and EIR; Green Specific Plan and EIR; TTM 33444. -27- TN /City of La Quinta / Page 28 TTM 33444 EA18.25.05 Findings of Fact Buildout of the site will have a less than significant impact on public services. The proposed project will be served by the County Sheriff and Fire Department, under City contract. Buildout of the proposed project will generate property tax and the City will capture substantial sales tax from the relatively high discretionary expenditures, which will offset the costs of added police and fire services, as well as the costs of general government. The project will be required to pay the mandated school fees in place at the time of issuance of building permits, although student generation is expected to be lower than that of a non- resort/retirement housing. The project will be located within a private gated community with common recreational and common open space amenities, which may offset demand for other recreational facilities in the City. The project proponent shall comply with the City's Quimby Fee Ordinance (Chapter 13.48 Park Dedications). Gated access and on -site security is also expected to reduce demand for police services. Mitigation Measures None required. Mitigation Monitoring and Reporting None required. Sources: La Quinta General Plan and EIR; Green Specific Plan and EIR; TTM 33444. Findings of Fact Buildout of the site will have a limited impact on City or County recreational facilities. The proposed project's residents will have access to but are expected to generate a low demand for City parks and open space areas. The new residents may result in an increased use of local trails, although the level of increase is not expected to be significant. The residential development will provide large lots (most over 10,000 s.f. of sufficient size for a private pool and private open space. Common recreation facilities and landscaped open space areas and trails are also incorporated into the Plan. The project proponent shall comply with the City's Quimby Fee Ordinance (Chapter 13.48 Park Dedications). Mitigation Measures None required. -28- Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact XIV. RECREATION -- a) Would the project increase the use of X existing neighborhood and regional parks or other recreational facilities such that substantial physical deterioration of the facility would occur or be accelerated? b) Does the project include recreational X facilities or require the construction or expansion of recreational facilities, which might have an adverse physical effect on the environment? Sources: La Quinta General Plan and EIR; Green Specific Plan and EIR; TTM 33444. Findings of Fact Buildout of the site will have a limited impact on City or County recreational facilities. The proposed project's residents will have access to but are expected to generate a low demand for City parks and open space areas. The new residents may result in an increased use of local trails, although the level of increase is not expected to be significant. The residential development will provide large lots (most over 10,000 s.f. of sufficient size for a private pool and private open space. Common recreation facilities and landscaped open space areas and trails are also incorporated into the Plan. The project proponent shall comply with the City's Quimby Fee Ordinance (Chapter 13.48 Park Dedications). Mitigation Measures None required. -28- TN /City of La Quinta / Page 29 TTM 33444 EA/8.25.05 Applicable Previous Mitigation Measures The mitigation measures set forth above are comparable to and update those set forth in the Green EIR (SCH#94112047) and associated addendum. Additional mitigation measures set forth in previous approvals and to be applied to TTM No. 33444 include the following: Prior to Final Map approval, the applicant shall dedicate a multi - purpose trail easement within the Jefferson Street alignment for preservation of the Boo Hoff Trail. (EIR No.s 3 & 4) Mitigation Monitoring and Reporting None required. Sources: La Quinta General Plan and EIR; Green Specific Plan EIR and Associated Traffic Report (Endo Eng. 1994); TTM 33444; Traffic Analysis Update for Green Specific Plan (Urban Crossroads, 2005); Jefferson Street Alignment Mitigated Negative Declaration, 1995. -29- Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact XV. TRANSPORTATION/TRAFFIC -- Would the project: a) Cause an increase in traffic, which is X substantial in relation to the existing traffic load and capacity of the street system (i.e., result in a substantial increase in either the number of vehicle trips, the volume to capacity ratio on roads, or congestion at intersections)? b) Exceed, either individually or X cumulatively, a level of service standard established by the county congestion management agency for designated roads or highways? c) Result in a change in air traffic patterns, X including either an increase in traffic levels or a change in location that results in substantial safety risks? d) Substantially increase hazards due to a X design feature (e.g., sharp curves or dangerous intersections) or incompatible uses (e.g., farm equipment)? e) Result in inadequate emergency access? X f) Result in inadequate parking capacity? X g) Conflict with adopted policies, plans, or X programs supporting alternative transport- ation (e.g., bus turnouts, bicycle racks)? Sources: La Quinta General Plan and EIR; Green Specific Plan EIR and Associated Traffic Report (Endo Eng. 1994); TTM 33444; Traffic Analysis Update for Green Specific Plan (Urban Crossroads, 2005); Jefferson Street Alignment Mitigated Negative Declaration, 1995. -29- TN /City of La Quinta / Page 30 TTM 33444 EA/8.25.05 Findings of Fact The Green Specific plan provided for the development of up to 267 single family dwellings on the subject residential site and up to 10 lots on the not -a -part 12.5 acre parcel adjacent to The Quarry. The original traffic analysis for the Green SP assumed standard residential uses and applied a conservative trip generation rate. Based upon the reduced number of lots, an adjusted trip generation rate that better accounts for retiree and vacation home use at the site and consistent with the City General Plan, the project will generate 880 average daily trips (ADT) at buildout. This is compared to the 2,640 ADT projected in the 1994 Endo traffic study. Therefore, the proposed TTM 33444 represents a significant reduction in projected traffic impacts. The tract map also serves to facilitate the eventual extension of the new Jefferson Street General Plan alignment southward and into the Travertine project. The alignment of Jefferson Street was approved by the City in 1995 and for which a separate parcel was created via Parcel Map No. 28617 on the subject property. The applicant does not propose to reduce the Jefferson Street right -of -way but has proposed the construction of a single lane in each direction, which has been determined adequate to meet project and background traffic demand. Approvals for the extension of Jefferson Street across lands owned by the US Bureau of Reclamation ' (USBR) and managed by CVWD must be secured before the approved Jefferson Street realignment can be extended south from Avenue 58 to northeast corner of the Quarry Ranch property, which has provided right -of -way for the roads continuation to the TTM NO. 33444 boundary. The applicant and the City are ' currently coordinating with CVWD and the USBR to secure these approvals. The proposed project is consistent with or less intense than the land use densities analysed in the Green Specific Plan/EIR and the General Plan and its EIR. Traffic levels in the area of the proposed project are expected to be low and operating conditions at acceptable levels at buildout of the project and General Plan. The subdivision does not include unsafe curves or other features that could pose a meaningful traffic hazard. Impacts associated with the buildout of the project site are expected to be less than significant. Mitigation Measures None required. ' Applicable Previous Mitigation Measures The mitigation measures set forth above are comparable to and update those set forth in the Green EIR (SCH#94112047) and associated addendum. Additional mitigation measures set forth in previous ' approvals and to be applied to TTM No. 33444 include the following: 1. Prior to recordation of the Final Map, the City Building and Safety Department and ' Engineering/Public Works Department shall ensure that clear unobstructed sight distances have been provided at all intersections proposed on -site. (EIR No. 2) 2. Prior to issuance of building permits, the applicant shall coordinate with Sunline Transit Authority regarding, where applicable, the appropriate placement of support facilities for the public transportation system. (EIR No. 7) ' 3. Prior to the issuance of building permits, the applicant shall contribute on a fair share basis to the cost of area -wide improvements by participating in the City of La Quinta Infrastructure Fee program, which includes traffic signalization. (EIR No. 8) Mitigation Monitoring and Reporting None required. -30- TN /City of La Quinta / Page 31 TTM 33444 EA/8.25.05 Sources: La Quinta General Plan and EIR; Green Specific Plan EIR and Associated Traffic Report; TTM 33444. ■ Findings of Fact Domestic water and sanitary sewer services are provided to the site by CVWD, which has facilities in the ' project vicinity and can serve the site. The developer will be required to provide off -site wells in accordance with CV WD requirements and at locations to be approved by CV WD. The developer may be required to also participate in the construction of elevated storage reservoir, the location of which has not yet been determined. CVWD is expected to serve as the CEQA Lead Agency for this future reservoir as a separate project. Other utilities, including electrical power, natural gas, telephone and cable are available at or in the vicinity of the project site. The service providers will provide specific directives for extending services to the site and will collect connection and usage fees to balance for the cost of providing services. The ' construction of the proposed project is expected to have less than significant impacts on utility service providers and infrastructure. -31- Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact XVI. UTILITIES AND SERVICE SYSTEMS Would the project: a) Exceed wastewater treatment X requirements of the applicable Regional Water Quality Control Board? b) Require or result in the construction of X new water or wastewater treatment facilities or expansion of existing facilities, the construction of which could cause significant environmental effects? C) Require or result in the construction of X new storm water drainage facilities or expansion of existing facilities, the construction of which could cause significant environmental effects? d) Have sufficient water supplies available X to serve the project from existing entitlements and resources, or are new or expanded entitlements needed? e) Result in a determination by the X wastewater treatment provider that serves or may serve the project that it has adequate capacity to serve the project's projected demand in addition to the provider's existing commitments? f) Be served by a landfill with sufficient X permitted capacity to accommodate the project's solid waste disposal needs? g) Comply with federal, state, & local X solid waste statutes and regulations? Sources: La Quinta General Plan and EIR; Green Specific Plan EIR and Associated Traffic Report; TTM 33444. ■ Findings of Fact Domestic water and sanitary sewer services are provided to the site by CVWD, which has facilities in the ' project vicinity and can serve the site. The developer will be required to provide off -site wells in accordance with CV WD requirements and at locations to be approved by CV WD. The developer may be required to also participate in the construction of elevated storage reservoir, the location of which has not yet been determined. CVWD is expected to serve as the CEQA Lead Agency for this future reservoir as a separate project. Other utilities, including electrical power, natural gas, telephone and cable are available at or in the vicinity of the project site. The service providers will provide specific directives for extending services to the site and will collect connection and usage fees to balance for the cost of providing services. The ' construction of the proposed project is expected to have less than significant impacts on utility service providers and infrastructure. -31- i TN /City of La Quinta / Page 32 TTM 33444 EA/8.25.05 1 Mitigation Measures None required. 'T pplicable Previous Mitigation Measures he mitigation measures set forth above are comparable to and update those set forth in the Green EIR (SCH#94112047) and associated addendum. Additional mitigation measures set forth in previous approvals and to be applied to TTM No. 33444 include the following: 1. Prior to construction the developer shall contact the Fire Department for verification of current fire protection development requirements. All new construction shall comply with the existing Uniform Fire Code requirements and all applicable statutes, codes, ordinances, or standards of the Fire Department. (EIR No. 3) ' 2. All buildings over 5,000 square feet, excluding single - family residences, shall be equipped with automatic fire sprinkler systems. The Fire Department and Building and Safety Department shall review and approve all bui8ldings during building plan review. (EIR No. 4) 3. Prior to issuance of building permits, the developer will provide proof of funding of the required fire mitigation fee to the City of La Quinta Finance Department and the Riverside County Fire Department (EIR No. 6) ' 4. Prior to the issuance of building permits, the developer or subsequent home builder shall provide proof of funding to the Coachella Valley Unified School District in accordance with the applicable legislative authorized school impact fee. (EIR No. 7) 5. Necessary expansion of on -site and off -site electric lines and substations shall be identified by the applicant during the processing of the tentative tract map. The developer or future homebuilder shall consult with the Imperial Irrigation District (IID) to ensure adequate new facilities are provided with construction of each phase of the project. The developer or future homebuilder shall show proof of communications with IID to the Building and Safety department prior to Final Map approval. (EIR No. 8) ' 6. If electric service is extended to the site, the developer will be required to pay all extension costs from the existing lines. A funding mechanism shall be established for the reimbursement to the developer for the extension of costs as future connections are tied into Specific Plan electric lines. This funding ' mechanism shall be established with the City's Finance Department during the tentative tract map approval process. (EIR No. 9) . 7. Necessary expansion of on -site and off -site natural gas distribution lines shall be identified by the applicant during the processing of the tentative tract map. The developer or future homebuilder shall consult with the Southern California Gas Company (SCG) to ensure adequate new facilities are provided with construction of each phase of the project. The developer or future homebuilder shall show proof of communications with SCG to the Building and Safety Department prior to Final Map approval. (EIR No. 10) 8. If natural gas service is extended to the site; the developer will be required to pay all extension costs from the existing lines. A funding mechanism shall be established for the reimbursement to the developer for the extension of costs as future connections are tied into Specific Plan gas lines. This funding mechanism shall be established with the City's Finance Department during the tentative tract map approval process. (EIR No. 11) 9. Necessary expansion of on -site and off -site telephone and cable lines shall be identified by the applicant during the processing of the tentative tract map. The developer or future homebuilder shall consult with the Verizon and Time Warner to ensure adequate new facilities are provided with construction of each phase of the project. The developer or future homebuilder shall show proof of communications with said providers to the Building and Safety department prior to Final Map approval. (EIR No.s 12 & 14) -32- TN /City of La Quinta / Page 33 T"TM 33444 EA/8.25.05 10. If telephone and cable service is extended to the site, the developer will be required to pay all extension costs from the existing lines. A funding mechanism shall be established for the reimbursement to the developer for the extension of costs as future connections are tied into Specific Plan telephone and cable lines. This funding mechanism shall be established with the City's Finance Department during the tentative tract map approval process. (EIR No.s 12 & 14) ' 11. Developers shall provide separate well- marked on -site recycling bins for plastic, glass, and newspaper to increase participation in recycling programs, including those associated with the implementation of AB 939. The developer shall coordinate with the Recycling Coordinator of the Community ' Development Department prior to the issuance of building permits ensuring compliance with AB 939. (EIR No. s 15 & 16) Mitigation Monitoring and Reporting None required. Sources: La Quinta General Plan and EIR; Green Specific Plan EIR and Associated Traffic Report (Endo Eng. 1994); TTM 33444; -33- Potentially Less Than Less Than No Significant Significant w/ Significant Impact Impact Mitigation Impact XVII. MANDATORY FINDINGS OF SIGNIFICANCE -- a) Does the project have the potential to X degrade the quality of the environment, substantially reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below self - sustaining levels, threaten to eliminate a plant or animal community, reduce the number or restrict the range of a rare or endangered plant or animal or eliminate important examples of the major periods of California history or prehistory? b) Does the project have the potential to achieve short-term, to the disadvantage of X long -term environmental goals? b) Does the project have impacts that are X individually limited, but cumulatively considerable? ( "Cumulatively consider- able" means that the incremental effects of a project are considerable when viewed in connection with the effects of past projects, the effects of other current projects, and the effects of probable future projects)? c) Does the project have environmental X effects, which will cause substantial adverse effects on human beings, either directly or indirectly? Sources: La Quinta General Plan and EIR; Green Specific Plan EIR and Associated Traffic Report (Endo Eng. 1994); TTM 33444; -33- TN /City of La Quinta / Page 34 t TTM 33444 EA/8.25.05 Findings of Fact XVII. a): The project has a limited potential to degrade the quality of the environment by minimally ' reducing wildlife habitat for sensitive species, including the Peninsular bighorn sheep. The project will not cause a fish or wildlife population to drop below self - sustaining levels, nor will it threaten to eliminate a plant or animal community, reduce the number or restrict the range of a rare or endangered plant or animal ' or eliminate important examples of the major periods of California history or prehistory. Mitigation measures are included in this document to avoid and minimize impacts to a less than significant level. XVII. b): The proposed project supports the long -term goals of the General Plan by providing a variety of ' housing opportunities for City residents. Concurrent with development of the subject subdivision, substantial areas will be placed in permanent open space and conservation. Long -term environmental goals are not expected to be significantly compromised by approval ad development of TTM 33444. ' XVII. c): The construction of 219 residential lots within an approved Specific Plan area will result in a 17% lowering of densities on this site compared to Specific Plan approves, will not have considerable cumulative impacts and is consistent with the General Plan designation and the Specific plan on the property. XVII. d) The proposed project has the potential to adversely affect human beings, due to regional air ' quality impacts and exposure of people and property to potentially significant ground shaking. Since the Coachella Valley is in a non - attainment area for PM10, and the site will generate PM10, which can cause negative health effects, the air quality discussion, above, includes a number of mitigation measures to reduce ' the potential impacts on air quality. Mitigation Measures None required. Mitigation Monitoring and Reporting None required. XVIII. EARLIER ANALYSES. ' Earlier analyses may be used where, pursuant to the tiering, program EIR, or other CEQA process, one or more effects have been adequately analyzed in an earlier EIR or negative declaration. Section 15063(c)(3)(D). In this case a discussion should identify the following on attached sheets: ' a) Earlier analyses used. Identify earlier analyses and state where they are available for review. The following documents have served as the basis of the analysis conducted in this Initial Study and are ' available for review at the La Quinta City Hall, Community Development Department, located at 78-495 Calle Tampico, La Quinta, CA. Contact person is Mr. Fred Baker, Principal Planner, who can be reached at &760)777-7125. ' Travertine and Green Specific Plan and EIR La Quinta General Plan and EIR Coachella Valley Draft MSHCP Environmental Assessment No. 2002 -452 for Quarry Ranch SP No. 98 -032 & TTM No. 30651 ' Environmental Assessment No. 2002 -454 for Quarry Ranch Amendment to SP No. 98 -032 b) Impacts adequately addressed. Identify which effects from the above checklist were within the scope ' of and adequately analyzed in an earlier document pursuant to applicable legal standards, and state whether such effects were addressed by mitigation measures based on the earlier analysis. ' Not applicable. -34 t TN /City of La Quinta / Page 35 TTM 33444 EA/8.25.05 c) Mitigation measures. For effects that are "Less than Significant with Mitigation Incorporated," describe the mitigation measures, which were incorporated or refined from the earlier document and the extent to which they address site - specific conditions for the project. See above categorical discussions and mitigation measures. -35- �o �00 wW o UM M L) C"' h�l i IL M I ■ Project Boundary N 1 Miles E Source: Coachella Valle, Y Association of Governments -1 OMEMEW" 01A TERRA NOVA & Research, Inc. M1 Exhibit MMMMOM TTM No. 33444 La Quinta, California -� 6 Exhibit TERRA NOVA ® TTM No. 33444 Ap La Quinta, California project Vicinity Planning & Research, Inc. Aerial View TN /City of La Quinta TTM 33444 EA/8.24.05 Technical Reports General Biological Resources Assessment of the Green Specific Plan Site and Tentative Tract Map No. 33444 La Quinta, California Prepared by AMEC Earth & Environment, Inc. 3120 Chicago Avenue, Suite 110 Riverside, CA 92507 March 30, 2005 General Biological Resources Assessment of the Green Specific Plan Site and Tentative Tract Map No. 33444 La Quinta, California Prepared for: Terra Nova Planning and Research, Inc 400 S. Farrell Drive, Suite B -205 Palm Springs, CA 92262 (760) 320 -9040 Prepared by: AMEC Earth & Environmental, Inc. 3120 Chicago Avenue, Suite 110 Riverside, CA 92507 (951) 369 -8060 AMEC Job # 3- 2252 -0023 David Kajtaniak &.Nathan Moorhatch Biologists david.kajtaniakc@amec.com nathan. moorhatchOamec.com 'Survey conducted on: October 15 &;.l 8, 2004 Report'Date: March 30;.2005: ' Terra Nova Planning and Research, Inc Green Specific Plan/TTM 33444 ' General Biological Resources Assessment March 2005 I ' SUMMARY ' AMEC was contracted by Terra Nova Planning & Research, Inc. to perform a general biological survey and habitat assessment on a 331 ± acre site comprising the southern half of Section 29, Township 6 South, Range 7 East, as shown on the U.S.G.S. 7.5 minute Martinez Mountain, ' California Quadrangle. The Green Specific Plan site is located south of Avenue 58 in the City of La Quinta, Riverside County, California. The site is surrounded by undeveloped land on the south, west, and east sides. Only the northern edge of the property is bordered by residential ' development and a golf course (The Quarry). This report addresses the entire 331 ± acre Specific Plan Area, and focuses on the ninety acres in the eastern half of the property proposed for residential development within the approved Specific Plan, (TTM 33444). A literature review was conducted to identify. sensitive biological resources known from the ' vicinity of the project site. This included a consultation with the California Department of Fish and Game's computerized data base, the California Native Plant Society's Rare and Endangered Plants of California, and a review of records contained in the website for the ' Coachella Valley Multiple Species Habitat Conservation Plan. Pertinent documents from the AMEC library and files were also consulted. In addition, previous biological assessments for this site or adjacent development projects were consulted for this report. ' As noted above, although AMEC biologists assessed the habitat present over the majority of the 331± acre property, a special emphasis was placed on the eastern 90- acres. This area is planned for residential development, with 220 houses; Specific Plan approval allows for up to ' 277 homes. The majority of the 90 -acre subdivision site contained a declining Desert Dry Wash Woodland plant community (72 percent, approximately 65 acres) with pockets of Sonoran creosote bush scrub (28 percent, approximately 25 acres). Portions of the site have been ' disturbed by human activities (some trash dumping and off road vehicle use). Most of this remaining Desert Dry Wash Woodland (DDWW) appears to be cut off from surface flows by the upstream Guadelupe Levee, which directs flows from the Devil Canyon drainage into the USBR ' Dike No. 4 impound area to the southeast. An indicator of the general biological quality of the majority of the site is the high species ' diversity .present, with 99 species of plants and animals observed during the field surveys. No :'special. status wildlife or plant species were observed on the Green Specific Plan property during,.the two -day site survey. Direeted,;surveys:were conducted for two wildlife. species. The TTM 33444 development area :;wassurveyed. utilizing .30- foot,wide:transects suitable -for detection of Desert Tortoise (.Gopherus -agas*h) "sign per U. S. Fish and Wildlife Service survey protocols. No desert tortoises:or their ' sign were observed 'during the survey. A habitat assessment for Burrowing Owl (Athene :cunicularia) . was also conducted. Although no Burrowing Owls or their sign was detected, ' suitable habitat for this species is present. Portions of the proposed subdivision and much of the remainder of the property are potential habitat for the federally threatened Peninsular bighorn sheep (Ovis canadensis). This species ' could be impacted by factors associated with housing developments such as noise, lights, domestic animals, and recreational activities (hiking). Approximately two - thirds of the entire Terra Nova Planning and Research, Inc Green Specific Plan/TTM 33444 General Biological Resources Assessment March 2005 331 ± acre site is within bighorn sheep critical habitat, including possibly twelve to seventeen proposed houses in the southern area of the proposed TTM 33444 development (See Map 2). The southwest portion of the project site is within the proposed Multiple Species Habitat Conservation Plan conservation area (See Map 1). Currently, as many as seventeen planned houses would be built within the Conservation Area. "CERTIFICATION: I hereby certify that the statements furnished in the attached exhibits present .data and information required for this biological evaluation, and that the facts, statements, and information presented are true and correct to the best of my knowledge and belief." Dave Kajtaniak Biologist ' Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 ' General Biological Resources Assessment March 2005 TABLE OF CONTENTS PAGE 1.0 INTRODUCTION ............................................................................... ..............................1 2.0 METHODS ........................................................................................ ..............................1 ' 3.0 RESULTS ......................................................................................... ..............................2 3.1 Soils ....................................................................................... ..............................2 3.2 Vegetation .............................................................................. ..............................3 3.3 Wildlife LIST OF MAPS Map 1. Biological Resources .................................................................. .............................13 Map 2. Bighorn Critical Habitat ............................................................... .............................14 LIST OF TABLES Table 1. Sensitive Plants occurring or potentially occurring on the Green Specific Plan Site.............................................................................................. ..............................6 Table 2. Sensitive Amphibians and Reptiles occurring or potentially occurring on the GreenSpecific Plan Site .............................................................. ..............................7 _Table 3. Sensitive Fish occurring or potentially occurring on the Green Specific Plan Site.............................................................................................. ..............................7 Table 4. Sensitive Birds occurring or potentially occurring on the Green Specific Plan Site.. .... ....................................................................... ............................... .7 Table .5. Sensitive Mammals occurring or potentially occurring on the Green Specific Plan' Site ...................................................................................... ..............................8 Table'6. Sensitive Insects occurring or potentially occurring on the Green Specific PlanSite .....:.....................................................................:.......... ..............................8 Table 7. Sensitive Habitats occurring or potentially occurring on the Green Specific PlanSite .........:............................................................................ ..............................9 KEYTO TABLES 1 THROUGH 7 ................................................................ .............................10 Page 4.0 DISCUSSION ................................................................................... ................:............11 ' 4.1 Mitigating Impacts to Desert Dry Wash Woodland ................ .............................12 4.2 Mitigating Impacts to Migratory Birds .................................... .............................13 ' 4.3 Mitigating Impacts to Peninsular Bighorn Sheep 4.4 Mitigating Impacts to Watercources ...................................... .............................13 4.5 Detailed Information Sensitive Species on selected .............. .............................14 5.0 LITERATURE CITED AND REFERENCES ..................................... .............................15 LIST OF MAPS Map 1. Biological Resources .................................................................. .............................13 Map 2. Bighorn Critical Habitat ............................................................... .............................14 LIST OF TABLES Table 1. Sensitive Plants occurring or potentially occurring on the Green Specific Plan Site.............................................................................................. ..............................6 Table 2. Sensitive Amphibians and Reptiles occurring or potentially occurring on the GreenSpecific Plan Site .............................................................. ..............................7 _Table 3. Sensitive Fish occurring or potentially occurring on the Green Specific Plan Site.............................................................................................. ..............................7 Table 4. Sensitive Birds occurring or potentially occurring on the Green Specific Plan Site.. .... ....................................................................... ............................... .7 Table .5. Sensitive Mammals occurring or potentially occurring on the Green Specific Plan' Site ...................................................................................... ..............................8 Table'6. Sensitive Insects occurring or potentially occurring on the Green Specific PlanSite .....:.....................................................................:.......... ..............................8 Table 7. Sensitive Habitats occurring or potentially occurring on the Green Specific PlanSite .........:............................................................................ ..............................9 KEYTO TABLES 1 THROUGH 7 ................................................................ .............................10 Page ' Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment 1 March 2005 LIST OF APPENDICES Appendix 1. Plant and Vertebrate Species List for the Green Specific Plan Site ' Appendix 2. Site Photographs Page ii Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment March 2005 1.0 INTRODUCTION This report presents the results of a general biological survey and habitat assessment conducted by AMEC Earth and Environmental (AMEC) on the 331± acre Green Specific Plan property located immediately south of The Quarry at La Quinta golf course and the Quarry Ranch subdivision in the City of La Quinta, Riverside County, California. AMEC was contracted by Terra Nova Planning & Research, Inc. to perform this study. The 331 ± acre site is comprised of the south half of Section 29, Township 6 South, Range 7 East, as shown on the U.S.G.S. 7.5 minute Martinez Mountain California Quadrangle (see Map 1). Ninety acres in the eastern half of the property are proposed for residential development, as shown on TTM 33444. The majority of the 90 -acre development site contained a declining (drought- stressed) Desert Dry Wash Woodland plant community (72 percent, approximately 65 acres) with pockets of Sonoran creosote bush scrub (28 percent, approximately 25 acres). Most of the Desert Dry Wash Woodland (DDWW) appears to have been cut off from upstream surface flow by the Guadelupe Levee located upslope and offsite. This property is undeveloped desert, but portions of the site have been disturbed by human activities (some trash dumping, and off road vehicle use via a four -wheel drive road through the middle of the site). The site is surrounded by undeveloped land on the south, west, and east sides, some of which is managed by the Bureau of Land Management. The eastern edge of the property is bordered by a rocky outcropping ( "Coral Mountain "). The western side 'of the TTM 33444 dedicated area is also bordered by rocky hills that are the foothills of the Santa Rosa Mountains. Only the northern edge of the property is bordered by residential development and a golf course (The Quarry and Quarry Ranch). Multiple water channels are present throughout the unit. Some of these channels display evidence of transporting heavy seasonal flows of water. 2.0 METHODS This assessment consisted of a literature review, a field survey to perform a general inventory of plants and animals, a focused desert tortoise survey (Gopherus agassizi), and a determination of habitat suitability for sensitive species of flora and fauna (particularly Burrowing Owl [Athene cunicularia]). AMEC staff also consulted with local representatives of the California Department of Fish and Game (CDFG) personnel on some biological issues. The literature review was conducted to identify sensitive biological resources known from the vicinity of the project site. This included consultation with the CDFG computerized database sand. a:review�of the.California Native Plant Society's (CNPS) Rare.and Endangered Plants of Califorrna .(Tibor, 2001). Previous biological...assessments submitted, by other consulting companies.•for this site or adjacent 'development projects. were'. incorporated into this report. These ;include studies performed in 1994 for the Green property and for the Travertine property (Thomas Olsen Associates 1994a, 1994b). Pertinent documents from the AMEC library and files were also consulted, as was The Soil Survey of Riverside County, California, Coachella Valley Area (Knecht 1980). An important information source was the draft of the Coachella Valley Multiple Species Habitat Conservation Plan (CVMSHCP, CVAG 2004). Page 1 ' Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 ' General Biological Resources Assessment March 2005 Nathan Moorhatch, Dave Kajtaniak, and John Green of AMEC conducted the field surveys on October 15 and 18, 2004. The surveys were performed during the early morning through early afternoon hours. The temperature ranged from the mid 60's to low 90's OF with cloud cover that varied from 40% to 75% and winds of 0 to -5 miles per hour. The survey was performed to ' generate as complete a biological inventory as possible, although special attention was given to searching for presence of desert tortoise sign and a habitat assessment for burrowing owl. The biologists surveyed the proposed development area and additional outlying areas included in the 331± acre property, utilizing 30 -foot wide transects suitable for detection of Desert Tortoise (Gopherus agassizii) sign per U. S. Fish and Wildlife survey protocols. Only the most steep and rugged areas were omitted from the survey. A total of - -150 acres was surveyed by these ' transects. The assessment of the potential for occurrence of many of the sensitive plants and wildlife was based on geographic range, habitat associations, and soil types. Focused surveys for sensitive plants were not conducted, since the majority of sensitive plant species recorded from the area are not detectable at this time of they year. All plants encountered on the parcel were identified ' and some specimens were taken to Andrew. Sanders of the University of California Riverside Herbarium for additional verification /identification. All plant and vertebrate species observed were recorded in field notes. Unobserved wildlife ' species were identified through indirect sign (e.g. scat, tracks, nests, burrows). A list of all plant and wildlife species observed or detected on the site is included at the end of the report. ' Scientific nomenclature for this report is from the following standard reference sources: plant communities, Holland (1986); flora, Hickman (1993) and Munz (1974); reptiles, Stebbins (2003); birds, American Ornithologists Union (1998); and mammals, Laudenslayer and Grenfell (1983). 3.0 RESULTS 3.1 'Soils The Soil Survey of Riverside County, California, Coachella Valley Area (Knecht 1980) was reviewed to determine the soil associations and soil types occurring on the project site. The ' overall soil association is the Carsitas - Myoma - Carrizo association, which consists of nearly level .to moderately steep, somewhat excessively drained or excessively drained sands, fine sands, ' gravelly. sands, cobbly sands and stoney sands on alluvial fans and valley fill. The primary mapping unit occurring on the site is Carsitas gravelly sand. There is also a small percentage of the Myoma fine sand unit in the wash along the northeastern boundary and southwestern ' section of the eastern unit. The Rock outcrop unit is present on rocky hillsides on the property edges. The following are descriptions of these units: • Carsitas gravelly sand (CdC), 0 to 9 percent slope. This nearly level to moderately ' sloping soil is on alluvial fans along the east, north, and. west edges of the Coachella Valley. Classified as moderately to.strongly. alkaline. Page 2 Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 ' General Biological Resources Assessment March 2005 • Myoma fine sand (MaB), 0 to 5 percent slope. This nearly level to gently sloping soil is on alluvial fans where they merge with the finer textured flood plain and basin soils. Also classified as moderately to strongly alkaline. • Rock outcrop (RO). This rolling to very steep land types is in mountainous areas. ' From 75 to 100 percent of the surface is covered with outcrop of granite, gneiss, mica schist, and sandstone. 3.2 Vegetation The plant communities present on the proposed development site are characterized by Holland (1986) as Desert Dry Wash Woodland (DDWW) and Sonoran Creosote Bush Scrub vegetation. Upon consultation between AMEC biologists and CDFG personnel concerning the condition of the DDWW present on the site; the CDFG representative stated that the DDWW in the subject development area should not be characterized as viable long -term habitat, but one in decline due to its isolation from essential upstream flows by flood diversion levees (Eddie Konno, pers.comm.). This declining Desert Dry Wash Woodland was the dominant plant community, covering -72% ( -65 acres) of the 90 -acre residential development site. The structure of this natural community varies from an open to dense, microphyllous thorn scrub woodland. Representative DDWW species observed on the site included: blue palo verde (Cercidium floridum ssp. floridum), honey mesquite (Prosopis glandulosa), catclaw (Acacia greggii), smoke tree (Psorothamnus spinosus), sweetbush (Bebbia juncea), and desert lavender (Hyptis emoryi). Sonoran Creosote Bush Scrub vegetation comprised -28% ( -25 acres) of the 90 -acre residential development site. Some of the plant species representative of this habitat type that were observed on the site included: creosote bush (Larrea tridentata), burrobush (Ambrosia dumosa), brittlebush (Encelia farinose), and ocotillo (Fouquieria splendens ssp. splendens). Sonoran Creosote Bush Scrub was present on the southern half of the 90 -acre development area, (along the base of the east and west hills, with one other small patch in the north central portion of this area); and was also sparsely distributed over the rocky slopes that constitute the majority of the remainder of the 331 ± acre site. Sixty plant species were identified during the survey. This number does not reflect the total number of plant species likely to occur on the site. Some spring annuals were undetectable due to the seasonal timing (early fall) of the field visit. This survey was an inventory of the perennial plants, late- germinating annual species, and dried remains of spring and summer annuals still present on the property. 3.3 Wildlife ' v6rtebrate�wildlife detected. on the Green Specific Plan site during the survey totaled thirty -nine species. {4 .reptiles, 32.birds, and 3--mammals). The inventory was limited by the short survey period; seasonal timing of the. field survey, and by the nocturnal and fossorial habits of many ' animals. The four reptile species observed during the survey included: side- blotched lizard (Uta ' stansburiana), zebra- tailed lizard (Callisaurus draconoides), Great Basin whiptail (Aspidoscelis tigris tigris), and desert iguana (Dipsosaurus dorsalis). Other common reptiles likely inhabit the rocky areas of the site, but were not observed during the surveys. Page 3 ' Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 ' General Biological Resources Assessment March 2005 Birds detected during the surveys include a mix of species common to undeveloped and ' developed areas of the Coachella Valley as well as some migrating birds. Some of the birds observed included red - tailed hawk (Buteo jamaicensis), American kestrel (Falco sparverius), common raven (Corvus corax), greater roadrunner (Geococcyx californianus), mourning dove (Zenaida macroura), house finch (Carpodacus. mexicanus), northern mockingbird (Mimus polyglottos), verdin (Auriparus f/aviceps), Anna's hummingbird (Calypte anna), yellow - rumped warbler (Dendroica coronata), black- throated gray warbler (Dendroica nigrescens), and black- ' tailed gnatcatcher (Polioptila melanura). Three mammal species: white - tailed antelope squirrel (Ammospermophilus leucurus), black - tailed jackrabbit (Lepus californicus), and coyote (Canis latrans) were observed or detected. ' Several species of nocturnal rodents are expected at this site, and many small mammal burrows were observed during the survey. Sensitive Species ' Plant or animal taxa may be considered "sensitive" due to declining populations, vulnerability to habitat change or loss, or because of restricted distributions. Certain sensitive species have been listed as Threatened or Endangered by the United States Fish and Wildlife Service (USFWS) or by the California Department of Fish and Game (CDFG), and are protected by the federal and state Endangered Species Acts and the California Native Plant Protection Act. ' Other species have been identified as sensitive by the USFWS, the CDFG, or by private conservation organizations, including the CNPS, but have not been formally listed as Threatened or Endangered. Such species can still be considered significant under the California Environmental Quality Act (CEQA). In addition, the draft CVMSHCP designates selected species in its conservation goals and attempts to protect core habitat areas for these species. ' The literature review, and AMEC biologists' knowledge of the site vicinity, indicated that as many as 24 sensitive plants, animals and habitat types potentially occur in the vicinity of the property. For a summary of sensitive species known to occur, or potentially occur in the vicinity of the property, see Tables 1 to 7. Most of the sensitive plants listed in Table 1 are associated with Sonoran or Mojavean desert scrub and /or desert wash habitats. The Green Specific Plan site does contain Sonoran desert scrub habitats as well as desert wash habitat preferred by Ayenia ( Ayenia compacta), glandular ditaxis (Ditaxis clariana) and California ditaxis (Ditaxis serrata var. californica). The site . cohtains some.: suitable habitat for the Deep Canyon snapdragon (Antirrhinum cyanthiferum) with -ro'cky areas located on the property and /or surrounding area. The remainder of the plants listed in Table 1 are not expected on the project site. Table 2 lists the species of sensitive amphibians and reptiles that have been recorded from the greater project vicinity (Martinez Mountain California Quadrangle). Of the five species listed in Table 2, only the Northern Red Diamond Rattlesnake (Crotalus ruber ruber) has a low probability of occurring on the site. The remaining four species of amphibians and reptiles are not expected to occur on or adjacent. to the site. Coachella Valley fringe -toed lizard (Uma inornata) and flat - tailed horned lizard (Phrynosoma mcallb) prefer fine, loose, windblown sand, Page 4 ' Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 ' General Biological Resources Assessment March 2005 interspersed with hardpan and widely spaced desert shrubs; and this specific habitat is not ' present on the project site. The project site also does not contain suitable habitat for the desert slender salamander (Batrachoseps major aridus). The 90 -acre (TTM 33444) development area was surveyed utilizing 30 -foot wide transects suitable for detection of Desert Tortoise (Gopherus ' agassizit) sign per U. S. Fish and Wildlife Service survey protocols. No desert tortoises or their sign were observed during the survey. ' Table 3 lists one species of fish that is associated with desert ponds, springs, marshes and streams. The desert pupfish (Cyprinodon macularius) is not present on the site due to the absence of suitable habitat. 1 � I � I � I � I � I � I Page 5 Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment March 2005 Table 1. Sensitive Plants occurring or potentially occurring on the Green Specific Plan. Page 6 w . 8 JA Antirrhinum cyathiferum F: No designation Sonoran Desert Feb -April Low Deep Canyon C: No designation Scrub, rocky sites snapdragon CNPS: List 2 R -E -D: 3 -1 -1 CV MSHCP: No Astragalus tricarinatus F: Endangered Joshua tree Feb -May Absent Triple- ribbed milk -vetch C: None woodland, Sonoran (site too low in CNPS: List 1 B desert scrub, hot elevation, no R -E -D: 3 -2 -3 rocky slopes in plants observed) CV MSHCP: Yes canyons Ayenia compacta F: None Mojave desert scrub, Mar -Apr Moderate Ayenia C: None Sonoran desert (preferred habitat CNPS: List 2 scrub, sandy and present on site) R -E -D: 2 -1 -1 gravelly washes, dry CV MSHCP: No desert canyons Bursera microphylla F: None Sonoran desert scrub Jun -July Absent Elephant Tree C: None (rocky) CNPS: List 2 R- E- D:3 -1 -1 CV MSHCP: No , Ditaxis clariana F: No designation Mojavean desert Oct -Mar Moderate Glandular ditaxis C: No designation scrub, Sonoran (habitat present CNPS: List 2 desert scrub, dry on site, but not R -E -D: 3 -2 -1 washes and rocky observed) CV MSHCP: No hillslo es Ditaxis serrata var. F: No designation Sonoran desert Mar -Dec Moderate californica C: No designation scrub, sandy washes (not observed, but California ditaxis CNPS: List 3 and alluvial fans of preferred habitat R -E -D: ? -2 -3 the foothills and on site) CV MSHCP: No desert slopes Heuchera hirsutissima F: No designation Subalpine coniferous May -Jul Absent Shaggy - haired alumroot C: No designation forest, Upper (habitat not CNPS: List 1 B montane coniferous present on site) R -E -D: 3 -1 -3 forests/ rocky CV MSHCP: No Nemacaulis denudata var. F: No designation Coastal dunes, desert March -May Absent gracilis _ C: No designation dunes, Sonoran (site lacks sand Slendermooly -heads CNPS: List 2 desert scrub dune habitat) R -E-D:i 2 =2 -1 CV`1MSHCP: No Stemodia durantifolia F: No designation Sonoran desert Jan -Dec Absent -Low Purple stemodia C: No designation scrub, wet sandy (not observed) CNPS: List 2 soils, drying river R- E- D:3 -3 -1 beds CV MSHCP: No Page 6 Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 GeneralBiological Resources Assessment March 2005 Thelypteris puberula var. F: No designation sonorensis C: No designation Sonoran maiden fern CNPS: List 2 R- E- D:2 -2 -1 CV MSHCP: No Meadows and seeps, Jan -Sep Absent streams (no habitat present on site) Table 2. Sensitive Amphibians and Reptiles occurring or potentially occurring on the ' " 'Green Specific Plan. z Table, 3. Sensitive Fish occurring or potentially occurring on the Green Specific Plan. i tec fi� � ENEMA Desert Tortoise Fed: THR Arid sandy or gravelly locales, Absent (Gopherus agassizi) Calif.: THR cacti, and thorn scrub. Also (no sign detected on a• CV MSHCP: Yes found in washes and canyon 90 -acre parcel during bottoms. focused survey) Flat- tailed horned lizard Desert washes and desert flats, Absent -Low (Phrynosoma mcalli) F: None fine sand for burrowing (marginal habitat, C: Special Concern species has been CV MSHCP: Yes extirpated from most of Coachella Valle Coachella Valley fringe- F: Threatened Sand dunes with fine, loose, Absent toed lizard C: Endangered windblown sand for burrowing (Fine, windblown, (Uma inornata) ' CV MSHCP: Yes loose sand is absent from site Desert slender F: Threatened Palm oasis, desert wash and salamander C: Endangered desert scrub Absent (Batrachoseps major CV MSHCP: No (No suitable habitat) aridus Northern Red - diamond F: No designation Scrub habitats, grasslands, Low Rattlesnake C: Special Concern woodlands, rock outcrops (not common in Crotalus ruber rube6 CV MSHCP: No desert z Table, 3. Sensitive Fish occurring or potentially occurring on the Green Specific Plan. i S° Table 4- Sensitive Birds occurring or potentially occurring on the Green Specific Plan. � ENEMA ..Hi,i`� 2s°'iTz�. ' s �ON � B211" (Ckpnnodon maculadus) e. o- -• • - • water sources) S° Table 4- Sensitive Birds occurring or potentially occurring on the Green Specific Plan. Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment March 2005 Prairie Falcon F: None (Nesting) inhabits dry, open Moderate (Falco mexicanus) C: Special Concern terrain; breeding sites located in (area located within (Ovis Canadensis nelsoni (Nesting) cliffs critical habitat) dps) CV MSHCP: No sandy washes dune habitat Burrowing, Owl F: None Coastal and desert scrub, Low (Athene cunicularia) C: Special Concern agriculture, urban and suburban (Not observed, but (Spermophilus CV MSHCP: Yes open space could move onto site Le Conte's thrasher F: None Desert resident, open desert Low to Moderate (Toxostoma /econtei) C: Special Concern wash, desert scrub, alkali desert (variety of habitat CV MSHCP: Yes scrub and desert succulent present on site) scrub Crissal thrasher F: None Desert riparian and desert wash Moderate (Toxostoma crissa/e) C: None habitats, nests in dense veg. (reported on site in CV MSHCP: Yes along streams /washes 1994 Loggerhead Shrike Fed: ND Occupies a wide variety of open Occurs Lanus ludovicianus Calif: CSC habitats within California, usually (nesting) with exposed perches from CV MSHCP: No which to scan for prey. Vermilion flycatcher F: None (Nesting) desert riparian adj to Absent (Pyrocephalus rubinus) C: Special Concern, irrigated fields, ditches, pastures (no suitable habitat) CV MSHCP: No Table 5. Sensitive Mammals occurring or potentially occurring on the Green Specific Plan. Peninsular bighorn F: Endangered Open desert slopes below Moderate sheep C: Threatened 4,OOOft, steep walled canyons (area located within (Ovis Canadensis nelsoni CV MSHCP: Yes and ridges bisected by rocky or critical habitat) dps) CV MSHCP: Yes sandy washes dune habitat Palms Springs round- F: Candidate Desert succulent scrub, desert, Moderate tailed ground squirrel C: Special Concern wash, desert scrub, alkali scrub (detected near site (Spermophilus CV MSHCP: Yes and levees on previous surveys) tereticaudus chorus Table'6. Sensitive Insects occurring or potentially occurring on the Green Specific Plan. Page &. —F�Ca "Sand dune ridges in vicinity of 0: Pto Coachella g�antbsand ` F None ' Absent ': treader cricket C: None Coachella Valley (site lacks sand IVlacrobaenetes val um ) CV MSHCP: Yes dune habitat Page &. Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment March 2005 Table 7. Sensitive Natural Communities occurring or potentially occurring on the Green Specific Plan. =• • • None • CV IVISHCP: Yes Page 9 Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment March 2005 Key to Tables: Definitions of status designations and occurrence probabilities. Federal designations: (federal Endangered Species Act,. US Fish and Wildlife Service): END: Federally listed, Endangered. THR: Federally listed, Threatened. ND: Not designated. State designations: (California Endangered Species Act, California Dept. of Fish and Game) END: State listed, Endangered. THR: State listed, Threatened. RARE: State listed as Rare (Listed "Rare" animals have been re- designated as Threatened, but Rare plants have retained the Rare designation.) CSC: California Special Concern Species. ND: Not designated. MSHCP designations: (draft Coachella Valley Multiple Species Habitat Conservation Plan) Y: Listed in the MSHCP. N: Not listed in the MSHCP. California Native Plant Society (CLAPS) designations: (Non - regulatory, compilation by a non - profit organization which tracks rare plants) List 1 B: Plants rare and endangered in California and throughout their range. List 2: Plants rare, threatened or endangered in California but more common elsewhere. List 3: Plants for which more information is needed. List 4: Plants of limited distribution; a "watch list." CNPS R -E -D Code: Rarity 1: Rare, but found in sufficient numbers and distributed widely enough that the potential for extinction or extirpation is low at this time. 2: Occurrence confined to several populations or one extended population. 3: Occurrence limited to one or a few highly restricted populations, or present in such small numbers that it is seldom reported. Endangerment 1: Not endangered. 2: Endangered in a portion of its range. 3: Endangered throughout its range. .Distribution 1: More or less widespread outside California. 2: Rare outside California. 3: Endemic to California (i.e., does not occur outside California). Definitions of occurrence probability: Occurs: Observed on the site by AMEC personnel, or recorded on -site by other qualified biologists. High: Observed in similar habitat in region by qualified biologists, or habitat on the site is a type often utilized by the species and the site is within the known range of the species. Moderate: Reported sightings in surrounding region, or site is within the known range of the species and habitat on the site is a type occasionally used by the species. Low: Site is within .the known range of the species but habitat on the site is rarely used. by the.species. Absent. A focused study failed to detect,the. species, or, no suitable habitat is present Page 10 Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment March 2005 One sensitive bird species was observed on the site. A Loggerhead shrike (Lanus ludovicianus) was observed on the site during the course of the surveys. This species may use the area for both foraging and nesting, since suitable nesting trees are present. Loggerhead Shrikes are considered a CSC by.the CDFG. Most of the sensitive bird species discussed in Table 4 are associated with riparian woodland or desert wash habitats. Those species preferring the desert wash habitat including the Le Conte's thrasher (Toxostoma ) have a low to moderate probability of using the site. The crissal thrasher (Toxostoma crissale) prefers dense vegetation in thickets or along washes. Although optimal habitat does not occur on the site, Thomas Olsen Associates reported sighting two crissal thrashers on this site in 1994. The vermilion flycatcher (Pyrocephalus rubinus) is most commonly encountered near water and is unlikely to utilize this area. The property provides moderate potential foraging habitat for the prairie falcon (Falco mexicanus), a raptor species that may also utilize the rocky portions of the site for breeding sites. All of the above- mentioned birds are considered "Species of Special Concern" (CSC) by the CDFG, but are not listed as threatened or endangered. Table 5 summarizes two sensitive mammal species that vary in their potential for occurrence on the site. Peninsular bighorn sheep (PBS) (Ovis canadensis) has a moderate potential to occur on the rocky hillsides present on the western portion of the site. The western portion of the site and a small area of the proposed development area is located within designated PBS critical habitat. There are few recent sightings from this area, however. The Palms Springs round - tailed ground squirrel (Spermophilus tereticaudus chlorus) was not observed on site, but it has been detected on previous surveys in the near vicinity. Due to the short duration of the site visit, additional surveys would be required to determine if these squirrels, which are somewhat adapted to disturbed conditions, inhabit the site. The one sensitive insect species listed in Table 6, the Coachella giant sand treader cricket ' (Macrobaenetes va/gum), is not expected to inhabit the site. The sand dune ridge habitat associated with this cricket is not present on the property. The California Natural Diversity Data Base reported one sensitive natural community in the ' vicinity: Desert Fan Palm Oasis Woodland. This community is not present on or adjacent to the Green Specific Plan site, and the site is devoid of any fan palms (Washingtonia filfera) and lacks evidence of any permanent water source. ' 4.0 DISCUSSION No sensitive wildlife or plant species were observed on the Green Specific Plan property during ' the.two -day survey. This survey was seasonally limited, and did not include focused surveys for sensitive plants or small mammal trapping. Despite this, a total of 99 plant and wildlife species were -observed. The majority of the 90 =acre TTM 33444 site is classified as declining: Desert ' Dry Wash Woodland vegetation with pockets of Sonoran Creosote Bush scattered throughout the eastern portions of the site. The majority of the rest of the 331 ± acre site consists of rocky slopes that are also vegetated with sparse Sonoran Creosote Bush Scrub, although additional ' DDWW is also present on the northwestern portion of the project site in an area that is not slated for development. As stated previously, AMEC biologists consulted CDFG personnel concerning the condition of the DDWW present on the site, and the CDFG representative stated 1. Page 11 ' Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment March 2005 that the DDWW in the 90 -acre TTM 33444 development area should not be characterized as ' viable long -term habitat, but one in decline due to its isolation from essential upstream flows by flood diversion levees (Eddie Konno, pers.comm.). ' Heavy disturbance has occurred in the northwestern wash areas, as well as the wash located one ridge to the east, from stream maintenance activities. On -site heavy equipment operators encroaching from the off -site property to the north claimed clearing of the streambed was ' necessary to prevent flood damage to the golf course property. The site was reviewed for compliance with the draft CVMSHCP. The proposed development is partially located within the modeled habitat and range for the Peninsular bighorn sheep. It also ' encroaches to a limited extent within the proposed Santa Rosa and San Jacinto Mountains Conservation Area (Map 1) as set forth in the Coachella Valley Draft MSHCP. The project proponent has met with the MSHCP proponent (Coachella Valley Association of Governments, ' CVAG) and a minor MSHCP map revision more consistent with site topography is being considered, which would eliminate this encroachment. ' Portions of the Dry Desert Wash Woodland, along with the Sonoran Creosote Bush habitat, remain as viable biological resources and the majority of the 331 ± acre site is located within "critical habitat" for Peninsular bighorn sheep (Map 2). Bighorn sheep that may occasionally ' utilize the adjacent hillsides would most likely be impacted by factors associated with housing developments such as noise, lights, domestic animals, and recreational activities (hiking). Only the northern boundary of the property has been developed with the remaining area relatively ' undisturbed. The site also provides habitat for a number of common species. The proposed residential development (TTM 33444) could result in removing all existing biological resources on the 90 acres and potentially disrupt natural ephemeral watercourses. However, the ' proposed development plan has been modeled to preserve and /or restore these watercourses located along the base of the mountains, and the mitigation measures discussed below would further help minimize some of these impacts. ' 4.1 Mitigating Impacts to Desert Dry Wash Woodland All proposed development sites and any new access roads should be clearly marked prior to ' grading to limit damage to adjacent habitat. Grading should be limited to construction areas. Vegetation removal should be limited to actual construction sites, and overall should be as minimal as possible. When possible, the larger trees should be left standing or transplanted for landscaping. Existing roads should be utilized to minimize damage to native habitat. Staging ' areas for vehicles and construction equipment should be limited to existing disturbed areas such as dirt roads and pads. CDFG personnel have also recommended planting blue palo verde and ' other. appropriate DDWW .vegetation in perimeter drainages to be located adjacent to the toes of slope, on ahe:: east 'and..west side. of the site. This is consistent with the proposed development plan for TT33444 provided by the project applicant, which outlines preservation and /or ' restoration of the natural drainages and associated DDWW. CDFG also encouraged the incorporation of this type of DDWW treatment throughout the other project drainages to the greatest extent practicable. The project biologist shall approve the project landscape. palette, ' which will include components of the DDWW plant community. IPage 12 Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment March 2005 4.2 Mitigating Impacts to Migratory Birds The Riverside County guidelines regarding Migratory Bird Treaty Act compliance states: `To comply with the Federal Migratory Bird Treaty Act, any vegetation or tree removal, or grading occurring between February 1 to August 15 shall require a qualified biologist to conduct at least one nesting bird survey, and more if deemed necessary by the consulting biologist, ending no less than 3 days prior to grading. All trees on the project site, whether or not they will be removed, shall be surveyed for nesting birds. The results shall be reported to the Planning Department. If there are no nests present, this condition will be cleared. If nests are found, exclusionary fencing should be placed 200 feet around the tree for non - raptors and 500 feet for raptors, until the birds have permanently left the nest." Conducting construction activities outside the breeding season (August 16 through January 31) can avoid having to implement these measures. 4.3 Mitigating Impacts to Peninsular Bighorn Sheep Portions of the TTM 33444 development site and much of the remainder of the property are potential habitat for the federally threatened Peninsular bighorn sheep (Ovis canadensis). This species could be indirectly impacted by disturbance from construction noise, ground vibrations, artificial lighting, and presence of workers. Approximately two - thirds of the entire 331 ± acre site is within bighorn sheep critical habitat, including approximately twelve to seventeen proposed houses in the southwestern portion of the 90 -acre TTM 33444 development site (Map 2). The project proponent does not plan any development on the rocky hillsides and slopes that make up the majority of the western two thirds of the entire 331 ± acre project site. The draft CVSHCP suggests the following mitigation measures for reducing impacts to bighorn sheep. Construction of Covered Activities located within Peninsular bighorn sheep habitat should be conducted outside the January 1 to June 30 lambing season if it is determined that a lambing area is located within one mile of the project site or otherwise authorized through a Minor Amendment to the Plan with concurrence from the Wildlife Agencies. According to the Santa Rosa Mountains Wildlife Habitat Management Plan (Department of Interior,' BLM, Riverside District, Indio Resource Area and DFG, 1974) TTM 33444 development site is not within a mile of lambing locations. For new projects'in Conservation Areas, no toxic or invasive plant species may be used for landscaping. Other mitigation measures include: locating facilities at the lowest feasible elevation on the construction site; measures acceptable to the Wildlife Agencies will be taken to control disease vectors and fencing of facilities to prevent .exposure of bighorn sheep to hazardous site conditions. The project applicant may be requested to secure up to two (2) acres of offsite habitat for every acre of development within designated PBS Critical Habitat. This compensation ratio has been employed for other projects within PBS Critical Habitat. 4.4 Mitigating Impacts to Watercourses The CDFG has proposed that the applicant should file an application for a Section 1602 Streambed Alteration Agreement (SAA) and incorporate the same into his CEQA document for analysis. The design considerations described above will be referenced in the SAA and indicate adequate mitigation and basis for the agreement. Page 13 Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment March 2005 4.5 Mitigating Impacts to the Burrowing Owl The burrowing owl (Athene cunicularia) is a CDFG CSC. Although no burrowing owls were observed on the site during the surveys, there is a low potential that this species could move onto the site prior to construction activities. A qualified biologist should conduct a clearance survey for burrowing owls immediately prior to commencement of ground- breaking activities to ensure that no owls will be harmed. If an occupied burrow is found in an area that is to be developed, and development activities are to take place during the breeding season (defined as February 1 through August 31), then no disturbance should occur within 250 feet of the occupied burrow (or within 160 feet during the nonbreeding period). Avoidance also requires that a minimum of 6.5 acres of foraging habitat be permanently preserved contiguous with occupied burrow sites for each pair of breeding burrowing owls (with or without dependent young) or single unpaired resident bird. The configuration of the protected habitat should be approved by CDFG (CDFG 1995). Upon consultation with CDFG, approval may also be granted for passive relocation of burrowing owls outside the breeding season through installation of one -way doors. Page 14 Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment March 2005 5.0 LITERATURE CITED AND REFERENCES Abrams, L. 1923, 1944, 1941. Illustrated Flora of the Pacific States, vol. I - III. Stanford Univ. Press, Stanford, CA. ' Abrams, L. and R.S. Ferris. 1960. Illustrated Flora of the Pacific States, vol. IV. Stanford Univ. Press, Stanford, CA. American Ornithologists' Union. 1998. Check -list of North American Birds, 7th ed. Am. Ornithol. Union, Washington, D.C. Baldwin, B. G., S. Boyd, B. J. Ertter, R. W. Patterson, T. J. Rosatti, and D. H. Wilkin. 2002. The ' Jepson desert manual: Vascular plants of southeastern California. Univ. Calif. Press, Berkeley, CA. California Department of Fish and Game. 1995. Staff Report on Burrowing Owl Mitigation. California Department of Fish and Game. 2004. Martinez Mountain Quadrangle printout, California Natural Diversity Data Base, Rarefind database. Compton Associates. 1994. Biological assessment: Green & Meyer Property, La Quinta, Riverside County, California. Compton Associates, Hemet, CA. Coachella Valley Association of Governments, 2004. Draft Coachella Valley Multiple Species Habitat Conservation Plan. Available on website at www.cvag.org Horchar,V.M. 2002. General Biological Assessment Quarry Ranch. VHBC, Incorporated, Riverside, CA. Hickman, J.C., ed. 1993. The Jepson Manual: Higher Plants of California. Univ. Calif. Press, Berkeley, CA Holland, R.F. 1986. Preliminary descriptions of the terrestrial natural communities of California. Calif. Fish Game, Sacramento, CA Ingles, L.G. 1965. Mammals of the Pacific States. Stanford University Press, Stanford, CA. Knecht, A.A. 1980. Soil Survey of Riverside County, California, Coachella Valley. Soil Conserv. Serv., Washington, D.C. Munz, P.A. 1974. A Flora of Southern California. Univ. Calif. Press, Berkeley, CA National Geographic Society. 1999. Field Guide to Birds of North America (Third Edition). National Geographic Society, Washington D.C. Stebbins, R.C. 2003. A Field Guide to Western Reptiles and Amphibians. Houghton Mifflin Company, Boston, MA. Thomas Olsen Associates. 1994. Biological Assessment. Green & Meyer Property, La Quinta, California. Thomas Olsen Associates Inc., Hemet, CA. Thomas Olsen Associates. 1994. Biological Assessment: Travertine Site, La Quinta, California. Thomas Olsen Associates Inc., Hemet, CA. Tibor, D. 2001. Inventory of Rare and Endangered Plants of California, Special Publication #1, Sixth Edition. 387 pgs. California Native Plant Society, Sacramento, CA. Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment March 2005 U.S. Department of Interior, Bureau of Land Management, Riverside District Office, Indio Resource Area, and California Department of Fish and Game. 1974. Santa Rosa Mountains Habitat Management Plan. Page 16 Map 1. Green Specific Plan TTIVI 33444- Biological Resources 90-Acre Development Area Project site Area within PBS Critical Habitat PBS Critical Habitat Surveyed Mitigation Area: Total area = 12.29 acres Yap Source: USGS 7.5' Martinez MotAwh LA. A, (Desert Dry Wash Woodland) Map 2. Green Specific Plan: Bighorn Critical Habitat Desert Dry Wash Woodland ;� _ � Project Boundary 0 2000 FEET Creosote Bush Scrub ® Conservation Area 4 lap Source: USGS 7.5' Martinez Mountain Quad. ame , ". ' Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment March 2005 Appendix 1 Vascular Plants Observed on the Green Specific Plan Project Site, La Ouinta, California October 15, 2004 Page 19 ANGIOSPERMAE DICOT FLOWERING PLANTS DICOTYLEDONEAE Acanthaceae Acanthus Family Justicia californica Chuparosa ' Amaranthaceae Amaranth Family Amaranthus fimbriatus fringed amaranth ' Asclepiadaceae Milkweed Family Sarcostemma cynanchoides ssp. hartwegii Climbing milkweed ' Asteraceae Sunflower Family Adenophyllum porophylloides San Felipe dyssodia Ambrosia dumosa Burrobush Bebbia juncea Sweetbush ' Encelia farinosa Brittlebush Geraea canescens Desert sunflower ' Hymenoclea salsola Palafoxia arida Cheesebush Spanish needles Pectis papposa chinch -weed Perltyle emoryi Rock daisy Peucephyllum schottii Pygmy -cedar Pleurocoronis pluriseta Arrow -leaf Psathyrotes ramosissima Turtleback Stephanomeria pauciflora Wire - lettuce Boraginaceae Borage Family ' Cryptantha angustifolia narrow - leaved cryptantha Cryptantha sp. Cryptantha Tiquilia plicata Plicate coldenia ' Brassicaceae Mustard Family *.Brassica tournefortii Sahara mustard ' *.Descurainia pinnata western tansy mustard . Cactaceae Cactus Family :Ferocactus cylindraceus California barrel cactus I' Opuntia echinocarpa Golden cholla Opuntia ramosissima Diamond cholla Page 19 ' Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 ' General Biological Resources Assessment March 2005 Chenopodiaceae Goosefoot Family Atriplex polycarpa Allscale *Chenopodium album Iamb's quarters Cucuribitaceae Gourd Family Brandegea bigelovii Brandegea Euphorbiaceae Spurge Family Chamaesyce albomarginata rattlesnake weed Chamaesyce polycarpa Desert sand mat Ditaxis neomexicana Common ditaxis Fabaceae Pea Family Acacia greggii Catclaw Caesalpinia virgata Small- leaved Hoffmanseggia Cercidium f/oridum ssp. floridum Blue palo verde Dalea mollis Silk Dalea Psorothamnus schottii Schott's indigo bush Psorothamnus spinosus Smoke tree Page 20 ' Fouquieriaceae Ocotillo Family Fouquieria splendens ssp. splendens Ocotillo Hydrophyllaceae Waterleaf Family ' Phacelia distans wild heliotrope ' Krameriaceae Krameria grayi Rhatany Family White Rhatany Lamiaceae Mint Family ' Hyptis emoryi Desert- lavender Loasaceae Loasa Family ' Mentzelia albicaulis Small- flowered blazing star Petalonyx thurberi Sandpaper plant ' Malvaceae Mallow Family Hibiscus denudatus Desert hibiscus Nyctaginaceae Four O' Clock Family ' Allionia..incarnata Windmills Abronia villosa sand verbena ' Mirabilis bigelovu Wishbone bush . Onagraceae Evening Primrose Family Camissonia boothii Booth evening primrose Camissonia claviformis Brown -eyed primrose Page 20 Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment March 2005 Plantaginaceae Plantago ovata Polemoniaceae Langloisia setosissima ssp. setosissima Polygonaceae Chorizanthe brevicornu Chorizanthe rigida Eriogonum inflatum Eriogonum sp. Solanaceae Datura discolor Nicotiana obtusifolia Physalis crassifolia Viscaceae Phoradendron californicum Zygophyllaceae Larrea tridentata * Tribulus terrestris MONOCOTYLEDONEAE Poaceae *Schismus barbatus * - denotes a nonnative species Plantain Family Woolly plantain Phlox Family Bristly langloisia Buckwheat Family Brittle spineflower Spiny -herb Desert trumpet Buckwheat sp. Nightshade Family Desert Thornapple Desert tobacco Thick - leaved ground -cherry Mistletoe Family Desert mistletoe Caltrop Family Creosote bush Puncture vine MONOCOT FLOWERING PLANTS Grass Family Mediterranean schismus Vertebrates Observed or Detected on the Green Specific Plan Project Site, La Ouinta, California REPTILES Iguanids Desert Iguana Horned:Lizards and-allies Zebra - tailed Lizard Side - blotched lizard October 15, 2004 REPTILIA Iguanidae Dipsosaurus dorsalis Phrynosomatidae Callisaurus draconoides Uta stansburiana Page 21 Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment March 2005 Whiptails and relatives Great Basin whiptail BIRDS Pelicans American White Pelican (flyover) Bitterns and Herons Great Egret Swans, Ducks, and Geese Mallard Kites; Eagles, Hawks, and allies Red - shouldered Hawk Red - tailed Hawk Caracaras and Falcons American Kestrel Plovers and Lapwings ' Killdeer Pigeons and Doves Mourning Dove Inca Dove Cuckoos, Roadrunners, and allies Greater Roadrunner Hummingbirds ' Anna's Hummingbird Costa's Hummingbird Woodpeckers ' Ladder- backed Woodpecker Northern Flicker Tyrant Flycatchers Black phoebe ' Say's Phoebe Shrikes Loggerhead Shrike Jays, Magpies, and Crows Common Raven Teiidae Aspidocelis tigris tigris AVES Pelecanidae Pelecanus erythrorhynchos Ardeidae Ardea alba Anatidae Anas platyrhynchos Accipitridae Buteo lineatus Buteo jamaicensis Falconidae Falco sparverius Charadriidae Charadrius vociferus Columbidae Zenaida macroura Columbina inca Cuculidae Geococcyx californianus Trochilidae Calypte anna Calypte costae Picidae Picoides scalaris Colaptes auratus Tyrannidae .Sayornis nigricans Sayornis saya Laniidae Lanius ludovicianus Corvidae Corvus corax Page 22 ' Terra Nova Planning and Research, Inc Green Specific Plan TTM 33444 General Biological Resources Assessment ' March 2005 Penduline Tits and Verdin Remizidae Verdin Auriparus flaviceps Wrens Troglodytidae Rock Wren Salpinctes obsoletus Bewick's Wren Thryomanes bewickii ' Old World Warblers and Gna tcatchers Sylviidae Black- tailed Gnatcatcher Polioptila melanura Mockingbirds, Thrashers, and allies Mimidae Northern Mockingbird Mimus polyglottos ' Wood - warblers Parulidae Orange- crowned Warbler Vermivora celata Yellow- rumped Warbler Dendroica coronata ' Black- throated Gray Warbler Dendroica nigrescens Emberizines Emberizidae Sage Sparrow Amphispiza belli White- crowned Sparrow Zonotrichia leucophrys Icteridae Blackbirds and allies ' Brewer's blackbird Euphagus cyanocephalus Great - tailed grackle Quiscalus mexicanus ' Fringilline and Cardueline Finches Fringillidae House Finch Carpodacus mexicanus Lesser Goldfinch Carduelis psaltria ' MAMMALS MAMMALIA ' Rabbits and Hares Leporidae Black- tailed Jackrabbit Lepus californicus Squirrels, Chipmunks, and Marmots Sciuridae White- tailed Antelope Squirrel Ammospermophilus leucurus Foxes, Wolves, and relatives Canidae ' Coyote (scat) Canis latrans Page 23 1 1 APPENDIX 2 ' SITE PHOTOGRAPHS 1 7 Photo 1. Dry Desert Woodland Wash habitat in eastern unit. i� b .© y» \7 __ Photo 2. Drainage surveyed M between eastern and northwestern unit. F Photo 4. Stream channel along northern edge of property (Channel had been altered by bulldozing activity). Photo 5. Dry Desert Woodland Wash habitat in eastern unit. Photo 6. Sonoran Creosote Bush Scrub habitat in eastern unit. FJ r � Nathan T. Moorhatch ' Wildlife Biologist/Herpetologist 1 Professional summary ' Mr. Moorhatch has over 13 years consulting experience performing a wide variety of biological surveys throughout California, spanning from the Sacramento Valley to the International Border. He has had a life -long interest in general biology, and obtained a degree in Zoology from the California State ' Polytechnic University at Pomona under Dr. Glen Stewart in 1991. Mr. Moorhatch has conducted biological and environmental assessments at project sites in Solano, Monterey, Tulare, Fresno, Inyo, Kern, Ventura, Santa Barbara, Los Angeles, San Bernardino, Orange, Riverside, San Diego, and Imperial counties in California, as well as in Nevada.. He has conducted the following types of assessments: rare plant species surveys; plant species inventory and vegetation mapping; revegetation plan preparation and implementation; general wildlife species surveys; focused sensitive wildlife species surveys and habitat quality assessments; sensitive wildlife species monitoring and relocations; small ' mammal trapping studies; Corps Section 404 waters /wetlands delineation and jurisdictional determination; CDFG 1601 -3 stream and riparian habitat assessments and jurisdictional determinations; and preparation of biological assessment reports and sections of EIS and EIR documents for federal, state, and /or county agency CEQA and NEPA environmental review. Professional experience includes serving as a lead biologist, supervising and managing biological compliance monitoring and sensitive species survey efforts for a variety of large -scale projects. Mr. Moorhatch has been authorized by the U.S. Fish and Wildlife Service to independently perform focused surveys for the federally endangered Delhi Sands Flower - loving Fly, Quino Checkerspot Butterfly, and the federally threatened California Gnatcatcher. Mr. Moorhatch has also been authorized to assist other permitted biologists with focused surveys for the Stephens' Kangaroo Rat, San Bernardino Kangaroo Rat, Pacific Pocket Mouse, Mojave Ground Squirrel, California Red - legged Frog, Least Bell's Vireo (nest searches), and Southwestern Willow Flycatcher (nest searches and surveys). He has also received both federal and state agency authorization for specific projects to capture, handle, process, and relocate the Desert Tortoise; and to capture, handle, and release the California Red - legged Frog. Mr. Moorhatch has extensive experience conducting herpetological studies including focused surveys and - monitoring of endangered species. He has . performed surveys for a wide variety of sensitive amphibians,and reptiles including: California Tiger Salamander, Tehachapi Slender Salamander, Large - blotched Ensatina, Arroyo Toad, California Red- legged. Frog, Mountain Yellow- legged Frog, Western Spadefoot, Southwestern Pond Turtle, Desert Tortoise, Switak's Barefoot Gecko, Blunt -nosed Leopard Lizard, San Diego Horned Lizard, Coachella Valley Fringe -toed Lizard, Flat- tailed Horned Lizard, :Orange- throated Whiptail, Southern Rubber Boa, and Two - striped Garter Snake. He has a deep personal interest in general Herpetology, and has undertaken numerous forays in the field in search of .both common and rare amphibian and reptile species in California, Nevada, Arizona, Utah, Texas, Kansas, Maryland, Virginia, Florida, Hawaii, Mexico (Districto Federale, Puebla, Veracruz, Sinaloa, Nayarit, Baja California Norte), Costa Rica, and British Columbia, Canada. Resume Division — Earth and Environmental Nathan T. Moorhatch resume Nathan T. Moorhatch ' He also is an avid birder, and has assisted in conducting surveys for California Gnatcatcher, Least Bell's Vireo, Burrowing Owl, Le Conte's Thrasher, Snowy Plover, Least Tern, and various nesting raptor species in Riverside, Orange, Los Angeles, Kern, San Diego, and San Bernardino counties. Mr. I' Moorhatch has conducted Bird Air Strike Hazard (BASH) studies on the Edwards Air Force Base Main Base Flightline during 1998 and 1999, and participated in a base -wide bird survey utilizing point counts to determine distribution and abundance of bird species on EAFB. He has also conducted bird use surveys ' of several landfill sites in San Bernardino and Tulare Counties in support of BASH studies related to local airports. Mr. Moorhatch is a member of the American Birding Association and the Audubon Society. His personal interest in birds has led him on numerous field searches in California, Arizona, Utah, Texas, ' Kansas, Florida, Hawaii, Mexico (Districto Federale, Puebla, Veracruz, Sinaloa, Nayarit, Baja California Norte), Costa Rica, and British Columbia, Canada. Mr. Moorhatch has conducted focused surveys for Delhi Sands Flower - loving Fly and Quino Checkerspot Butterfly; and has a Federal Endangered Species Permit [10(a)(1)(A)] for both of these ' insects. Mr. Moorhatch has also participated in "Fourth of July Butterfly Counts" sponsored by the North American Butterfly Association. He has a personal interest in Entomology and is a member of the Friends of the University of California, Riverside, Entomological Research Museum (FERM). ' Mr. Moorhatch has assisted in trapping surveys for several sensitive small mammals including: San Bernardino Kangaroo Rat, Los Angeles Pocket Mouse, Tehachapi Pocket Mouse, and Short -nosed .' Kangaroo Rat. He has also participated in focused surveys for San Joaquin Kit Fox, San Joaquin Antelope Ground Squirrel, Mojave Ground Squirrel, and Peninsular Bighorn Sheep. In addition to his experience with sensitive wildlife species, Mr. Moorhatch has conducted numerous ' surveys for sensitive plant species throughout California. He has conducted surveys for over 35 sensitive plant species, including limestone endemics, Big Bear Valley endemics, vernal pool species, and a wide variety of sensitive species in the San Joaquin Valley, Mojave and Colorado Deserts, and. various coastal and inland valley habitats. Mr. Moorhatch has also assisted in the preparation of revegetation plans, and has conducted restoration /revegetation activities including site preparation, seeding /transplanting, and monitoring.on Edwards Air Force Base. Additionally, he conducts general ' inventories of flora and fauna; and authors biological assessments and mitigation plans. Mr. Moorhatch also has a current California Department of Fish and Game Scientific Collector's Permit. ' Professional qualifications California Department of Fish and Game Scientific Collectors Permit #801166 -04 ' - Federal Endangered Species Permit (" 10a ") for Quino Checkerspot Butterfly, #TE029414 -1 Federal Endangered Species Permit ("10a ") for Delhi Sands Flower - loving Fly, #TE029414 - 1 Federal Endangered Species Permit (" 10a ") for Coastal California Gnatcatcher, #TE785148 -7 Authorized Individual for studies regarding the Desert Tortoise (Authorized to monitor, handle, and relocate desert tortoises when necessary for specific project implementation). ' Education B.S. Zoology (cum laude), California State Polytechnic University, Pomona, 1991 ' University of California, Riverside — Extension Course Work: Ornithology — A Field Study of Birds Victor Valley Community College: Ecology of Costa Rica, 2001 ' Resume Division — Earth and Environmental Nathan T. Moorhatch resume � I Nathan T. Moorhatch Location Riverside, California ■ Seminars, Workshops, and Symposia Desert Tortoise Council Symposium, 1992 -1999 '. Desert Tortoise Council Field Techniques Workshop, 1992, 1994 Mojave Ground Squirrel "CHIEF" Workshop. 1992 ' Declining Amphibians in California I, San Diego Natural History Museum, 3/97. Declining Amphibians in California ll, San Diego Natural History Museum, 3/98. ' Workshop on Year 2000 Draft Quino Checkerspot Butterfly Survey Protocol, Carlsbad, California, 1999. Planning for Biodiversity: Bringing Research and Management Together. 2/29- 3/2/00; Pomona, California. ' Arroyo Toad Symposium (Bufo califomicus): Natural History and Management Practices. 10/05/00; Marine Corps Air Station, Camp Pendleton, California. Current Research on Herpetofauna of the Sonoran Desert ll. 4/5 -7/02; Tucson, Arizona. ' Memberships American Birding Association Friends of the University of California, Riverside, Entomological Research Museum Desert Tortoise Council National Audubon Society Southwestern Herpetologist's Society Detailed Core Skills by Project Domestic Water Development and Supply Cadiz Land Company Inc. Exploratory Drilling and Proposed Water Line Surveys and Monitoring. Conducted presence /absence surveys and monitoring for Desert Tortoise and sensitive plants during exploratory drilling and surveys for proposed water line system right -of -ways, Danby and Cadiz, Fenner Valley, San Bernardino County, California. ' Coachella Valley Water District — Coachella Canal Realignment Surveys and Monitoring. Conducted/.coordinated presence /absence, clearance surveys, and monitoring for Desert Tortoise, Burrowing .Owl, and other sensitive. biological resources prior to, and during, construction /excavation of approximately 35 miles of new canal alignment. Oil and Gas Development and Supply Kramer Junction Line 6905 Expansion Project. Acted as an assistant Lead Biologist supervising a team of 30+ biologists and biological monitors for the installation and development of a 33 -mile natural ' gas pipeline project in the Mojave Desert. Conducted general and focused (for Desert Tortoise, Burrowing Owl, and sensitive plant species) biological surveys; Desert Tortoise burrow excavation, artificial burrow construction, processing, and relocation; Burrowing Owl burrow excavation, artificial ' burrow construction, and passive relocation; mitigation monitoring; personnel awareness training, yucca Resume Division — Earth and Environmental. Nathan T. Moorhatch resume � I Nathan T. Moorhatch and cacti transplantation, and vertical mulching; San Bernardino County; Southern California Gas Company. ' All American Pipeline Project. Conducted general and focused biological surveys and mitigation monitoring for the Desert Tortoise for exploratory geotechnical drilling activities in support of the All American Pipeline Project; San Bernardino County; All American Pipeline Company. ' Four Corners Pipeline Company (ARCO). Conducted Desert Tortoise Monitoring for two oil line leak repairs at Danby and Sheephole Pass, San Bernardino County, California. Four Corners Pipeline Company (ARCO). Conducted Desert Tortoise Monitoring for anode bed ' installation, San Bernardino County, California. Renewable Energy Resources ' Whitewater Wind Energy Conversion Systems. Acted as a Lead Biologist for the development, installation, and implementation of a wind energy park located in the San Gorgonio Pass area, on the northwestern outskirts of the Coachella Valley. Conducted general and focused (for Desert Tortoise, Burrowing Owl, and sensitive plant species) biological surveys; Desert Tortoise burrow excavation, ' artificial burrow construction, processing, and relocation; Burrowing Owl burrow excavation, artificial burrow construction, and passive relocation; mitigation monitoring; personnel awareness training for the life of the project; Shell Oil Corporation; Riverside County. ' Cabazon Wind Energy Conversion Systems. Lead Biological manager for the development, installation, and implementation of a wind energy park located in the San Gorgonio Pass area. Conducted general and focused biological surveys (for Desert Tortoise, Burrowing Owl, and Coachella ' Valley Fringe -toed Lizard), mitigation monitoring, and personnel awareness training for the life of the project; Cannon Power; Riverside County. ' Electrical Power Otay Mesa Generating Plant. Conducted habitat assessments and focused surveys for the Quino Checkerspot Butterfly the proposed generation plant site and throughout the associated transmission line easements on Otay Mesa from the U.S. /Mexican border north to Chula Vista; San Diego Gas and Electric Company; San Diego County. Valley to Auld Electrical Substation and Transmission Line Upgrade Project. Conducted mitigation ' monitoring for the Valley to Auld transmission line and electrical substation upgrade project. Significant biological issues included the California Gnatcatcher, Burrowing Owl, Stephens' Kangaroo Rat, Quino Checkerspot Butterfly, Belding's Orange- throated Whiptail, San Diego Coast Horned Lizard, and Southwestern Pond Turtle; Southern California Edison Company; Riverside County. U.S. Forest Service Arroyo Toad Surveys. 'Conducted habitat assessments and focused surveys for the Arroyo Toad ' throughout drainage systems containing potentially suitable and historically occupied habitat within the San Bernardino National Forest (including San Jacinto Range). Mountain Yellow - legged Frog Surveys. Conducted habitat assessments and focused surveys for the Mountain Yellow- legged Frog throughout drainage systems in historically occupied habitat within the San Bernardino National Forest. Transportation and Infrastructure ' State Highway 138. Conducted habitat assessments and focused protocol surveys for the Arroyo Toad for the proposed realignment of SR 138 between Interstate 15 and State Highway 18; San Bernardino County; Caltrans. ' Resume Division — Earth and Environmental Nathan T. Moorhatch resume Nathan T. Moorhatch ' Interstate 215 Seismic Retrofit Project. Conducted habitat assessments and focused protocol surveys for the Arroyo Toad for the proposed Interstate 215 seismic retrofit project in the City of Riverside; Riverside County; Caltrans. ' Interstate 15 Bridge Widening Project. Conducted habitat assessments and focused protocol surveys for the Arroyo Toad for the proposed Interstate 15 Bridge Widening Project over the Mojave River in the City of Victorville; San Bernardino County; Caltrans. 1 State Highway 18 Seismic Retrofit Project. Conducted habitat assessments and focused protocol surveys for the Arroyo Toad for the proposed seismic retrofitting of SR 18 at the crossing of the Mojave ' River in the town of Apple Valley; San Bernardino County; Caltrans. State Highway 79/371 Interchange Realignment Project. Conducted habitat assessments and focused protocol surveys for the Quino Checkerspot Butterfly for the proposed SR 79/371 Interchange ' Realignment Project in the community of Aguanga; Riverside County; Caltrans. Big Bear Dam /State Highway 18 Improvement Project. Conducted habitat assessments and focused protocol surveys for the Mountain Yellow- legged Frog for the proposed improvements of SR 18 at the ' crossing of the dam at the southwest end of Big Bear Lake in the San Bernardino Mountains; San Bernardino County; Caltrans. ' Opah Ditch Mining Reclamation Project. Conducted focused protocol surveys for the Desert Tortoise for the proposed Opah Ditch Mining Reclamation Project located south of Baker; San Bernardino County; Caltrans. ' Department of Defense Edwards AFB Main Base Flightline BASH study. Conducted Bird Air Strike Hazard (BASH) studies on the EAFB Main Base Flightline during 1998 and 1999.. Responsibilities included seasonal field inventories of bird species diversity and population size, coordination and management of experimental use of falconry as method to deter bird use, and preparation of documentation summarizing the effectiveness of bird control measures. ' Edwards AFB Base -wide Bird Inventory. Base -wide surveys utilizing point counts to determine distribution and abundance of bird species on EAFB, 2000 to 2002. Edwards AFB Base -wide Amphibian and Reptile Inventory. Conducted base -wide surveys to ' determine distribution and diversity of amphibian and reptile species on EAFB, 2004. Edwards AFB Desert Tortoise Monitoring. Conducted Desert Tortoise presence /absence surveys and monitoring throughout EAFB for a variety of projects including: Historic Homestead Well destruction, ' Monitoring Well Drilling, site restoration, and Joshua Tree transplantation. Edwards Air Force Base Revegetation Efforts. Has participated in revegetation /habitat rehabilitation on over 270 acres of desert scrub.on Edwards AFB. These largely successful efforts have incorporated ' a wide- variety of seeding methodologies including imprinting and hand seeding. Efforts have also included planting of nursery stock, transplanting of numerous desert shrub species, Joshua tree transplanting, and long -term viability monitoring. ' Nellis AFB Desert Tortoise and Rare Plant Survey. Conducted presence /absence surveys for Desert Tortoise and rare plants for proposed road construction and residential expansion projects. ' Travis AFB'Vernal Pool and Rare Plant Inventory. Conducted field surveys to inventory vernal pools and rare plant species on Travis AFB. Responsibilities included identification and mapping of vernal pools and rare plants (including the federal Endangered Contra Costa Goldfields Lasthenia conjugens). ' Resume Division — Earth and Environmental Nathan T. Moorhatch resume Nathan T. Moorhatch Vandenberg AFB Missile Transport Bridge Construction Monitoring. Conducted preconstruction surveys and relocation of California Red - legged Frog (Rana aurora draytoni►) and Unarmored Threespine Stickleback (Gasterosteus aculeatus williamsoni), as well as long -term monitoring of sensitive biological resources during construction of a new missile transport bridge over the San Antonio Creek drainage, Vandenberg AFB, Santa Barbara County, California. ' March ARB: Stephen's Kangaroo Rat Monitoring. Monitored a hazardous materials exploratory effort on a former weapons storage facility. Activities were monitored to ensure no adverse impacts to the endangered Stephen's Kangaroo Rat were incurred. Camp Pendleton MCB — Bullfrog Eradication. Participated in a bullfrog eradication effort to protect endangered Arroyo Toad (Bufo californicus) populations on the base. 29 Palms MCB — Desert Tortoise Surveys. Conducted presence /absence surveys for Desert Tortoise and sensitive biological resources on selected firing range areas on 29 Palms MCB. Employment history Wildlife Biologist/Ecologist, AMEC Earth and Environmental, Inc. November 2000 - present. Conducts field inventories of fauna and flora, performs literature reviews, prepares biological assessment reports emphasizing impact analysis, mitigation measures, and mitigation monitoring. Specializes in herpetological and entomological field studies, and also conducts ornithological field studies. Authorized by U.S. Fish and Wildlife Service to conduct focused surveys for the following Endangered or Threatened species: Quino Checkerspot Butterfly and Delhi Sands Flower - loving Fly. Wildlife Biologist/Herpetologist, Ogden Environmental and Energy Services, March 2000 - November 2000. Wildlife Biologist/Herpetologist, Tierra Madre Consultants, Inc., August 1999 -March 2000. Wildlife Biologist/Herpetologist, Earth Tech, August 1997 — August 1999 Assistant - Associate Biologist, Lilburn Corporation, November 1991 - August 1997 Publications Beaman;K.R., D.Goodward, N.Moorhatch, and C.W.Brown. 2005. Geographic Distribution: Hemidactylus turcicus. Herpetological Review 36(1.),. p.79. Languages Spanish - Fair IResume Division — Earth and Environmental Nathan T. Mooriiatch resume 1 "W�M_ Dave M Kajtaniak Staff Biologist Professional Summary Mr. Kajtaniak has over six years of professional endeavors with publicly and privately owned organizations. To date, he has conducted professional biological and environmental assessment work throughout San Bernardino, Riverside, Humboldt, Del Norte, and Siskiyou counties in California, as well as counties in northwest and southeast Ohio. Mr. Kajtaniak's work has focused on the research and management of Threaten, Endangered, and Sensitive Species of fish and plants in many different eco- regions. This has incorporated broad computer and mechanical skills to perform analyses and documentation within project - related assignments. His expertise has been derived from a formal education (BS in Field Biology) and extensive domestic field experience. Professional experience includes playing a key role in the development and implementation of a state -wide, holistic approach for watershed assessments. Mr. Kajtaniak has also served as the lead biologist, supervising and managing biological compliance monitoring and sensitive species survey efforts for a variety of large -scale I' projects, as well as conducting focused surveys and monitoring of a variety of endangered, threatened, and /or otherwise sensitive species. In addition to fieldwork, Mr. Kajtaniak authors environmental and biological assessments, watershed assessments, habitat suitability evaluations for sensitive species, mitigation and revegetation plans, instream habitat improvement projects, and comprehensive field inventories of flora and fauna. Professional Qualifications Education ' College of the Redwoods, Eureka, CA Furthering education, Semester Units 11, January 2002 to April 2003 Ohio University, Athens, OH B.S. in Field Biology, November 1999 Seminars, Symposia, and Workshops Survey of Major Plant Families of Southern California: Advanced Plant Identification Workshop. Rancho Santa Ana Botanic Garden, Claremont, CA 91711. Big Bear Fireshed Workshop. August, 2004, Fawnskin, CA. Society of American Foresters: Evaluation of San Bernardino National Forest Conference. May, 2004, Lake Arrowhead, CA. 16`', 17`h, 19`h, and 21 st annual California Salmonid Restoration Federation Conference: February and March 1998,1999, 2001, & 2003, various locations in California. Memberships Friends of the Big Morongo Canyon Preserve 2004 to Present Anza Borrego Foundation 2004 to Present California Native Plant Society — Humboldt Branch 2001 -2003 Languages English Detailed Core Skills by Project Domestic Water Development and Supply Coachella Canal Lining Project. I contributed to the development and writing of the Environmental Protection Plan for the Coachella Canal lining project. Participated in revegetation efforts, including surveying and mapping Sonoran thorn woodland and seed collection. Currently serving as a biologist for the biological monitoring and preconstruction surveys for sensitive biological resources during the bypass canal construction phase. Fern Valley Water District. Surveyed Fern Valley Water District's property to mark dead and dying stands of trees. Determined property boundaries and flagged in project site area. In addition to marking tree stands, area was surveyed for possible archaeological sites. Electrical Power SCE- Bark Beetle Project. Supervised and managed a crew of up to 5 field technicians for a eight month period conducting assessments in residential areas for dead and dying trees. This. project, located in the mountain communities of the San Bernardino and San Jacinto mountains, involved recording dead and dying tree species, mapping surveyed areas, and imputing and organizing field data. U.S. Forest Service Klamath, National,., Forest, Road Surveys. Conducted road / upslope watershed sediment delivery assessments following the U.S. Forest Service protocol. Inspected roads and road infrastructure features such as: culverts, water bars, and.inboard drainages, in determining sediment delivery to fish bearing streams. � I Klamath National Forest Stream Surveys. Performed California Department of Fish t and Game in- stream structure evaluations in fish bearing tributaries of the Klamath River. These evaluations included an assessment of current stream conditions, fish habitat improvement structures, and recommendations and designs of future watershed improvement projects. County Parks and Recreation ' Toledo Metroparks Ecosystem Restoration. Performed ecological restoration of different habitats in the Oak Openings region of Northwest Ohio. Through the active restoration and management (controlled burns, eradication of non - native species, seed 1 collection) of sand dunes, prairies, oak woodlands, and oak savannahs populations of endangered flora and fauna were increased as well as overall improvement in genetic diversity. Private Timberlands Pacific Lumber's Stream Watershed Analysis. Contributed to the fisheries portion of the Elk River Watershed Analysis in Humboldt County. This project entailed: snorkel dives for presence /absence of fish species, .habitat typing all class one watercourses, determining end of anadromy, mapping fish distribution by species, and writing and editing stream reports. Transportation and Infrastructure Cedar Canyon Fire. Coordinated with timber crews of tree removal in Cedar Glen after the Cedar Glen Fire. On site supervision of tree cutting selection and marking of trees in burned residential areas. Education and Community Outreach Trinidad Elementary School. Taught science, specifically stream ecology and fisheries, based curriculums in schools from grades first through seventh, including organizing and leading a class field trip to a local fish hatchery. Community Events. Participated in numerous community events aimed at improving environmental health and promoting public awareness. These included: Klamath River clean -up, Eureka Marsh Clean -up, Humboldt Bay Wildlife tree planting, Trinidad State Park non - native plant eradication, and Eureka food drive. Employment History Staff Biologist / Ecologist, AMEC Earth & Environmental, Inc.: August 2004 — present Prepares environmental assessments (EA), biological assessments (BA), and focused .sensitive species' surveys and habitat iassessments' for �both the public and private sectors. Conducts focused presence /absence surveys for rare and endangered flora and fauna including the Coachella Valley milkvetch, least Bells' vireo, burrowing owl and desert tortoise. Serves as a biological compliance monitor for large -scale construction projects. development of timber harvest plans. Completion of these tasks included the following: ' • Mapped fisheries information (fish distribution by species on Pacific Lumber Corporation basemaps, identified possible mitigation barriers, and access points for further field research). ' • Proposed proper mitigation in accordance with state laws for "threatened" species of salmonids under the federal Endangered Species Act. • Deciphered aerial. photos to determine vegetation landscapes. ' • . Rare plant species field surveys and habitat assessments on timber harvest plans and appurtenant roads. • Wetland identification. • Determined slopes, possible methods of timber extraction, and mapped . completed surveyed areas.. Forestry Technician, ACRT, Inc.: June 2004 — July 2004 Performed environmental consultation with private landowners and homeowner's association concerning forestry management and fuels modification. This work entails the following: flagging project boundaries, mapping surveyed areas, identifying ' archeological sites, wildlife habitat, watercourses, and other pertinent landscape features, tree species identification, marking dead and dying tree stands, and organizing 'data inventory. ' Forestry Technician, Mason Bruce and Gerard, Inc.: August 2003 — April 2004 Mr. Kajtaniak led a crew of field technicians surveying bark beetle infested trees throughout the San Bernardino National Forest. Some of my work duties included: ' cruise checking crew members for quality control, organizing and integrating data, and mapping surveyed areas. Mr. Kajtaniak also coordinated with logging crews directing tree removal within residential areas and private timberlands. Fisheries Biologist, Pacific States Marine Fisheries Commission: August 2001 — April 2003 Mr. Kajtaniak was an integral part of a multi- agency collaborative team conducting watershed assessments on river systems in Northern California. He performed in -field and academic research, analytical analysis of historic and current field data and previous studies, and extensive technical writing and editing watershed assessment reports. • Developed recommendations for habitat improvement, future monitoring studies, ' land -use activities, and the overall advancement of salmonid species. Participation in frequent multi- agency meetings and conferences conducting technical analysis and development of watershed assessment reports. Collected and integrated habitat inventory data, electro- fishing data, and ' other pertinent fisheries and watershed information. Fisheries, Botanical, and Forestry Technician — Natural Resources Management Corp.: April 2000 — August 2001 Utilized multidimensional skills to perform field and office duties of these positions. Primarily I lead fisheries and botanical crews on species surveys of private timber and rangelands; completed fish habitat and plant species reports; participation in the development of timber harvest plans. Completion of these tasks included the following: ' • Mapped fisheries information (fish distribution by species on Pacific Lumber Corporation basemaps, identified possible mitigation barriers, and access points for further field research). ' • Proposed proper mitigation in accordance with state laws for "threatened" species of salmonids under the federal Endangered Species Act. • Deciphered aerial. photos to determine vegetation landscapes. ' • . Rare plant species field surveys and habitat assessments on timber harvest plans and appurtenant roads. • Wetland identification. • Determined slopes, possible methods of timber extraction, and mapped . completed surveyed areas.. IAmeriCor s Volunteer — Watershed Stewards Project: Octobe r 1 99 7 — August 1999 ' As a member of the Watershed Steward's Project I conducted research and monitoring protocols pertaining to Pacific salmon species, created and implemented restoration projects throughout northern California, and integrated educational programs in various ' classroom and community settings. Some of my many tasks performed included: • Wrote and reviewed project and site plans including required federal and state permits. ' • Supervised California Conservation Corps crews and Humboldt fisheries students on habitat restoration projects throughout years of service with AmeriCorps. Implemented watershed improvement projects such as riparian re- vegetation, stream ' bank stabilization using bio- engineering techniques, and cattle exclusion fencing. • Conducted road / upslope watershed sediment delivery assessments following the U.S. Forest Service protocol. Land Management Crew Member, Toledo Metroparks: June 1995 - September 1997 ' Performed ecological restoration of different ecosystems (prairie, oak savannah, oak woodland, and sand dunes) in the Oak Openings region to improve populations of Threatened and Endangered species and promote genetic diversity of native species ' of flora and fauna. Helped propose habitat management plans and implemented these plans through various projects. Field work included: determining range, distribution, and abundance of Threatened and Endangered species of plants, continuous inventorying and monitoring of local flora, seed collection, prescribed burns, and non - native species eradication. i Grants and Publications Fisheries Grants 1998 -1999 Received over $40,000 in grants funding California Conservation Corps fisheries restoration projects and work tools for California Department of Fish and Game's volunteer fisheries program. Cannata,S. and D.M. Kajtaniak (2003 in Draft). Redwood Creek watershed synthesis report, Assessments of anadromous salmonids and stream habitat conditions of the Redwood Creek Basin. California Resources Agency and California Environmental Protection Agency; Sacramento, California. TN /City of La Quinta TTM 33444 EA/8.24.05 Technical Reports Cultural Resources Survey for the Green Specific Plan City of La Quinta Prepared by The Keith Companies Cultural Resources Division 2955 Redhill Avenue Costa Mesa, CA 92626 July 1994 L- ' A CULTURAL RESOURCES SURVEY FOR THE GREEN SPECIFIC PLAN, CITY OF LA QUINTA Prepared for. Mr. John Green c/o Winchester Asset Management 41 -865 Boardwalk, Suite 102 Palm Desert, CA 92260 Prepared by: The Keith Companies Cultural Resources Division 2955 Red Hill Avenue Costa Mesa, CA 92626 Report Author. Paul G. Chace, Ph.D., S.O.PA. Director of Cultural Resources July 1994 USGS Martinez Mtn. 112 acres, survey RIV -5324 � I � I EXECUTIVE SUMMARY A cultural resources survey to identify and assess cultural resources on the approximately ' 112 acres of the proposed Green Specific Plan development located in the City of La Quinta was undertaken by The Keith Companies Cultural Resources Division. No cultural resources were found to exist in the project area. A review of previously filed records and landmark registries, a field reconnaissance, a request of local Native American views, and a review of the regional literature found no archaeological sites or historical landmarks associated with the property. It is proposed, therefore, that no further specific planning considerations are warranted to mitigate any direct impacts from the proposed development upon known cultural resources. During the field reconnaissance, one archaeological site was located just beyond the boundary of the proposed project. This site is an isolated bedrock milling station with no associated archaeological materials, and the location was fully documented. As a non - unique archaeological resource under State law, this minor site should require no further planning consideration. Is it proposed, therefore, that no further planning considerations to mitigate any direct or indirect impacts this nearby non - unique site are warranted. There are a goodly number of previously recorded archaeological sites within the nearby ' region, but none is within one - quarter mile. Indirect impacts from the proposed develop- ment upon cultural resources in the surrounding region are not anticipated but are possi- ble. However, nearby properties are not subject to effective protective measures in connec- t' tion with the presently proposed project. It is proposed, therefore, that no further specific planning considerations to mitigate such indirect impacts are warranted. This region is consider a sensitive area for archaeological resources. Under CEQA ' (P.R.C. 21083.2i), the City "may make provisions for archaeological sites accidentally dis- covered during construction." The City may require that an archaeological monitor be ' present during the grading operations to evaluate and coordinate the recovery of any archaeological resources uncovered. TABLE OF CONTENTS EXECUTIVE SUMMARY i CHAPTER I. INTRODUCTION 1 CHAPTER H. PROJECT LOCATION AND ENVIRONMENTAL SETTING 2 CHAPTER III. METHODS OF INVESTIGATION g CHAPTER IV. ARCHAEOLOGICAL AND HISTORICAL BACKGROUND 10 CHAPTER V. RESULTS OF THE INVESTIGATION 13 CHAPTER VI. CONCLUSIONS AND PLANNING CONSIDERATIONS 15 APPENDIX A RECORD FILE SEARCH REPORT, and BIBLIOGRAPHY OF REGIONAL ARCHAEOLOGICAL INVESTIGATIONS APPENDIX B LETTER OF INQUIRY TO NEARBY TORRES- MARTINEZ TRIBAL COUNCIL APPENDIX C RESUME OF PRINCIPAL ARCHAEOLOGIST APPENDIX D RIV -5324 ARCHAEOLOGICAL SITE RECORD FORMS (NOT FOR PUBLIC DISTRIBUTION) ii � I ' CHAPTER I INTRODUCTION This report has been prepared at the request of Mr. John Green. Under his authorization ' of May 31, 1994, The Keith Companies Cultural Resources Division undertook a cultural resources survey to locate and assess any cultural resources located on the approximately 112 acres of property being proposed as the Green Specific Plan development. This Bevel- ' opment is located in the City of La Quinta, in south central Riverside County. This report describes the cultural resources survey of the Green tract. No archaeological sites and no historical landmarks were found to exist on this property. One archaeological site, however, was located just outside the boundary of the tract. This site was mapped and fully recorded. This minor site is an isolated bedrock milling feature, similar to other milling stations in the region. This site can be considered as a non - unique archaeological resource requiring no further consideration beyond the accomplished recordation. There- fore, it is proposed that the development of the Green tract will not have a significant ' effect on any recognized cultural resources and no further specific planning measures are warranted. The City, however, may require that an archaeological monitor be present during the grading operations to recovery of any archaeological resources uncovered. This report follows the procedures for addressing cultural resources planning considera- tions required under the California Environmental Quality Act of 1970 (P.R.C. 21000 et seq.) and as amended for archaeology in 1982 (P.R.C. 21083.2), as stipulated in the State C.E.Q.A. Guidelines, Appendix K, "Archaeological Impacts." This report conforms to the procedures recommended by the Society for California Archaeology, "Recommended 'Procedures For Archaeological Impact Evaluation' (1976), and those recommended by the State of California Office of Historic Preservation, "Archaeological Resource Management Reports (ARMR): Recommended Contents and Format" (1989). This investigation also complies with the Federal guidelines (36 CFR 60 and 36 CFR 800) to conform with the National Historic Preservation Act of 1966 (P.L. 89 -665; 16 U.S.C. 470) and the National Environmental Policy Act of 1969 (P.L. 91 -190; 42 U.S.C. 4321 - 4327). This cultural resources survey program was carried out under the direction of Paul G. Chace, Ph.D., Director of The Keith Companies Cultural Resources Division (TKC). Dr. ' Chace has been certified since 1977 as a member of the Society of Professional Archaeolo- gists (S.O.P.A.). Mr. Charles Reeves, B.A., with 22 years of experience in field archaeology, joined with Dr. Chace in the field reconnaissance. Mr. Brant Brechbiel, B.A., as Project Manager of The Keith Companies Cultural Resources Division, assisted in the report production. CHAPTER II PROJECT LOCATION AND ENVIRONMENTAL SETTING ' Project Location The tract being proposed for the Green Specific Plan development is located along the ' western margin of the Coachella Valley, in south central Riverside County, within the incorporated City of La Quinta. The project area is about five miles southeast of the City of La Quinta's new civic center and approximately ten miles south of Interstate 10 High- , way, as shown in Figure 1. The area is situated southwesterly of the end of Avenue 58, where the street terminates at Lake Cahuilla County Park. The Green Specific Plan is an irregularly shaped development area composed of approxi- mately 112 acres. The general location and the specific property included within the Green Specific Plan is composed of two separate pieces. These two pieces are the only two areas of relatively flat terrain in the southern half of Section 29, Township 6 South, Range 7 East. The eastern flat piece is about 100 acres, and the western piece is about 12 acres in size. The general location and the specific property included in the Green Specific Plan are shown in Figure 2, reproduced from portions of the U.S.G.S. Martinez Mtn. and Valer- ie quad maps, edition of 1981 and 1956, photorevised to 1988 and 1972, respectively. The remainder of the southern half of Section 29 is comprised of very steep and very rugged ridge slopes. It is anticipated that these rocky ridge slopes would not be included in the planned development. These rugged areas would be excluded from the proposed devel- opment, transferred, and dedicated as natural areas to be preserved as open space. Geography The Green Specific Plan property is comprised principally of two pieces of the nearly flat alluvial fans formed along the base of the mountains on the western margin of the Coachel- la Valley. The rugged Santa Rosa Mountains flank the western side of the Coachella Valley. The bases of these steep, rocky, mountainous slopes define the boundaries of the Green Specific Plan development except on the northern side and are illustrated in Figures 3 and 4. These mountains extend to elevations greater than 6,000 feet above sea level within four miles of the project area. These mountains and ridges are composed of Meso- zoic granitic and metamorphic rocks. 2 I : - N A.;'T I �' N A �-`L I i �:� _ _i ` - MEX7172�,_ N. \ 1 I ` \\ J� uer . . prir;� - -- -' —tee=._ - _M - - .� �A •r- 1 - ,_ TREE __7225 p _W ® N U--M E N T — rl 1 _ F7 Ranch ? • Ranch •Ranch ��. �r'•7p„ - y�� _ <�-_ -- '.x`.I /, i —� -tom- - c, j- be` �t `�ffl RAESS sr� LCD\ _._, — r — _. _.__ •' r..,ti �i \ - _. 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PoESERV ION �SBZ1- „r\• -r•.4� e'!�' G.-. r _ ��� < �? -�•O- t I i I� 1'at ins Wool 4 r f TORRES A - SALTO iSEA! P�pC ` ✓ .� ,, 's' DIARY RE VATIOiv �' L. _.1 1 �• _.-�.. `; i�F _,4 - ,• / �/ J:j :� i Oasis is 9 t i _ �G -rte RIVER E�4�l -a •'^1` D1EG0 �LlUIVTY 1Yt_ \, �✓.: { ' Figure 1. The general area of the Green Specific Plan along the western margin of the Coachella Valley in south central Riverside County, as shown on a portion of the USGS Santa Ana sheet of 1979. Scale 1” = 4 miles. 1 Figure 2. The location and specific property of the Green Specific Plan development, as shown on the USGS Martinez Mtn. and Valerie quad maps. Scale 1" _ 2000'. Figures 3 and 4. General view looking north across the eastern alluvial fan of the proposed development and beyond into the Coachella Valley from the knoll near the southeastern corner of the proposed Green Specific Plan; and a view of the z' alluvial fan rimmed by the rugged slope along the east side of the tract. Along the eastern side of the project area is a steep, small ridge of Mesozoic granite rocks. ' The ridge has the same geology but now is isolated from the nearby mountains proper by surrounding depositions of sandy alluvium. The eastern flank of this rocky ridge was inundated by prehistoric Lake Cahuilla and was covered by tufa. Locally, this colorful ' ridge is referred to as "Coral Reef." Most of this ridge is lust east and outside of the project. The Coachella Valley is an immense enclosed basin, an isolated trough extending north- ' ward from the Gulf of California. In long -past geological times, this trough was isolated from the ocean waters of the gulf by the immense delta deposited at the mouth of the Colorado River. The base of this valley basin, where the Salton Sea currently exits, is at an elevation of about 250 feet below sea level. The Alluvial Fan Deposits The soil deposits within the project area are alluvial fans composed of the eroded sandy gravel and sandy loam materials washed from the nearby steep flanks of the Santa Rosa Mountains. The gently sloping fan in the eastern portion of the project area extends from an elevation of about 60 up to about 165 above sea level, and the fan in the western portion of the development has elevations of about 80 to about 190 feet above sea level. The fans drain generally to the northward and eastward into the valley basin. In a few areas the fan surfaces have been eroded with small, shallow drainages. Sheet erosion and deposits from rare episodes of flash flooding off the adjacent mountain slopes are evident. The surface soils across the fans tend to be composed of loosely consolidated sands and fine gravels which appear to be relatively stable and ancient. Neither dunes of blown sand or rocky desert pavement formations occur on the fan surfaces of the project area. If any major prehistoric archaeological settlements were present, remnants of these sites should be evident. Prehistoric Lake Cahuilla and Abori gnal Settlements For most of the last two millennia, the basin of the Coachella Valley has been inundated by prehistoric Lake Cahuilla, an immense fresh -water lake that extended about 105 miles in length through the valley basin. This valley basin lake, on the western side of the Colorado River- .delta, was filled by the river's annual flood discharge. The lake filled the valley trough to a height of 40` above mean sea level and created beach line features at this elevation along the margins of the valley. About A.D. 1,500 the lake basin dried up rather suddenly when the Colorado River altered its course to the other side of its deltic cone and its.flow discharged-directly into the Gulf of California. When Lake Cahuilla filled the valley basin, the lake resources included abundant fishes, wildfowl, marsh plants; etc. These resources supported many aboriginal villages around the lake's shoreline. Other. groups from settlements in the Santa Rosa Mountains may have comedown seasonally to occupy camp sites along the shoreline. When the lake dried up, about 400 years ago, much of the local aboriginal population dispersed. Some people remained and adjusted their life -ways to the local desert re- sources, occupying settlements in the lake basin (such as Torres and Martinez) and in the surrounding mountains. In historic times these desert people have been known as the Cahuilla Indians. R Biota I' The current vegetation over the sandy alluvial fans of the project area is a sparse desert scrub biotic community. The principal plants present are creosote bush (Larrea tridentata), ' along with white sage (Salvia apiana) and mesquite (Prosopis juliflora). A few palo verde and smoke trees exist along the drainages, and several types of cactus occur infrequently across the desert surface of the alluvial fan. Various birds inhabit and are apparent in this plant community, along with numerous small reptiles. Some evidence of jackrabbits and ' cottontails is evident, but larger mammals appear to be rare or locally absent. While not rich in resources, in prehistoric times the project area probably was harvested for seed foods (such as mesquite beans and sage) and utilized for hunting small animals, par- ticularly cottontails and birds. The majority of the local plant species were utilized in' the economies of the aboriginal Cahuilla. This fan area along the margin of the valley was likely a foraging and hunting zone for the aboriginal people in the region. Recent Land Use In recent years the Green property obviously has been used by horse riders, recreational shooters, dove hunters, picnickers, and campers, as well as being used occasionally to dump ' trash. Several horse trails exist across the property which are used by riders from nearby stables. A dirt roadway (currently blocked with a berm) leads along the eastern side of Section 29 near the base of the ridge. Along this roadway and elsewhere there are modem rings of cobbles for camp fires, recent beer bottles, bullet cartridges, shot -gun shells, scat- ' tered shatters of clay pigeon targets, and occasional piles of dumped trash. One rusted auto body is present alongside the road. There is no evidence of any substantial historical development in the project area. The small alluvial fan in the western side of the Green Specific Plan abuts a new residential tract being developed to the north. Construction equipment from the new development has traversed onto the Green property and has disrupted the sandy surface soils, particular- ly in an area at the northwestern portion of the fan. 7 Ll ' CHAPTER III METHODS OF INVESTIGATION The methods employed for this investigation included: g (1) a review of previously filed site records and reports at the State's archaeological inventory center, (2) a comprehensive field reconnaissance over the surface of the proposed development area, (3) a request for Native American views on any sites of concern associated with the project area, and (4) a review of the existing archaeological and historical literature of the region. Previously Recorded Archaeology A review of all previously recorded archaeological and historical sites in the region and archaeological reports for the area was conducted by the Regional Information Center of the State's California Archaeological Inventory, housed at the University of California, Riverside. Their institutional record search was conducted in April 1994. The review covered the Green property in Section 29, an adjacent project in Section 33, and the sur- rounding lands within a radius of one mile. A copy of their letter report is provided as Appendix A. The results of the records search indicate that no record of any previous cultural resources survey of the Green property had been filed, and that no archaeological sites or historical landmarks were known in the project area. However, thirteen other archaeological investi- gations had been conducted in a one -mile radius of the Green property, and 42 archaeolog- ical sites have been previously recorded in these nearby projects. The reports on file with the California Archaeological Inventory indicated also that a number of brief archaeological investigations had been undertaken in earlier decades that were never fully documented. The site record forms indicate that various investigators have explored the camps along the old shoreline of prehistoric Lake Cahuilla in past decades. However, apart from the brief.notes on site forms, technical reports of any find- ings were not prepared or filed. Field Reconnaissance Following the review of previously filed records, the entire project property was traversed on foot in a systematic series of.transects to locate and assess any archaeological resources present. The transects were spaced about 20 to 25 meters apart, and the zones between the transects were carefully scanned. Ground visibility was generally excellent. Throughout most of the property 90% of the ground surface was visible. The margin of fans along the base of the ridge slopes was traversed and the rocky slopes were visually inspected for rock art panels or other possible archaeological features. The field survey was conducted on June 15, 1994. A total of 13 person -hours were expended on the field reconnaissance. Native American View tA request for Native American views on any sites of concern associated with the project area was sent to the nearby Torres - Martinez Tribal Council. A copy of this letter is pro- vided as Appendix B. In a telephone call from the Tribal Office on June 20, 1994, Mr. Phillip Morreo reported that there were no special sites of concern known in the project area. There are Native American concerns about archaeological locations elsewhere in the nearby region but not near the area of the Green Specific Plan. Existiniz Regional Literature An overview of the regional archaeological and historical literature provided the back- ground information contained in the following chapter of this report. This chapter summa- rizes current archaeological knowledge and the cultural traditions represented in the re- gion, as well as u iresolved problems of information and interpretation which give signifi- cance to the heritage resources which might be encountered. No reference was found to any published archaeological sites or historical landmarks on the project property. 1 9 ' CHAPTER IV ARCHAEOLOGICAL AND HISTORICAL BACKGROUND ' An overview of the existing archaeological and historical literature for the region is pre- sented in graphic form in Figure 5. The past societies that have occupied the central region ' of Riverside County are represented by cultural patterns in the archaeological record and by historical landmarks. ' The evidence for the very ancient occupations in southern California, before 9,000 B.C., is meager and controversial. Proposals for a Wisconsin Glacial Age Bi -Polar Tool Tradition, a Paleo- Indian Tradition, and for skeletal remains of Ancient Coastal People have been ' presented by various scientists. However, the validity and significance of the evidence has been disputed. Many of the chemical dating techniques employed in determining ancient dates have been shown to yield spurious results, and the basic claims for many of these very ' early finds have been withdrawn. Sites elsewhere in the Americas raise the possibility that very ancient occupation sites could be preserved in favorable geological situations. ' The San Dieguito Tradition people are recognized as early hunters occupying lakeside and streamside camps. Their camps are common in the deserts to the east and in San Diego County, but they rarely have been recognized in western Riverside County. Their tool assemblages are distinctive, primarily sharp -edged scrapers and long knives. It now seems ' apparent that this tradition emerged in the Great Basin, but the cause for its apparent late flourishing in southern California and its subsequent disappearance remain a mystery. The remains of Encinitas Tradition settlements appear about 7,000 B.C. throughout coastal southern California. This society was focused on the gathering of plant foods and shellfish. A diversity of hunting and fishing pursuits were modestly pursued, but little of the equip- ment required is archaeologically preserved. Cobble handstones and milling platforms are the characteristic tools encountered, while sharp -edged tools of flaked stone are few and notably simple. A late phase of this tradition occurs inland, away from the coast, where most camp sites were occupied only after 2,000 B.C. The apparent simplicity of the tech- nology, its persistence, and the many known sites imply a very successful adaptation to seasonal food resources. The specific food utilized, the strategies employed, and the cause of the apparent population shift inland have not been established as yet. The Campbell (Pinto) Tradition people were a society of desert hunters who apparently migrated to the coast. Their campsites exist around lakes, along inland streams, and along the coast from Santa Barbara southward to northern Baja California. Campbell Tradition sites are marked by numerous bones of land or sea mammals, large projectile points typi- cally made in a side - notched style, and a variety of hunting and seed milling equipment. A co- existence in some regions with Encinitas Tradition people seems proven; but the ulti- mate merging, evolution, or extinction of this cultural tradition remains to be investigated. 10 A.D. 1,990's A.D. 1.860 A.D. 1.830 A.D. 1,770 A.D. 1,600 A.D. 1.540 A.D. 800 A.D. 400 1,500 B.C. 2,000 B.C. Hakataya Tradition Colorado River Early Shoshonean Tradition Desert Great Basin (Amargosan Tradition) Encinitas Tradition Campbell (Pinto) Tradition Inland or North Coast 3,000 B.C. 7,000 B.C. San Dieguito Tradition Great Basin Lakes 9,000 B.C. Ancient Coastal People ,? 25,000 B.C. -------------------------- Wisconsin Glacial Age Asia & Bering Bi -Polar Tool Tradition Straits 80,000 B.C. Figure 5. Cultural patterns in the central Riverside County area. Indian Reservations < USA, Europe, American Developement Era psis & Africa Landless Indian Mexican Ranch- Mexico Period Pastoral Era & USA Colonial Spanish- Spain a Mission Era Mexico Late Shoshonean — — — — — Tradition Explorer S sin & Incident . England Hakataya Tradition Colorado River Early Shoshonean Tradition Desert Great Basin (Amargosan Tradition) Encinitas Tradition Campbell (Pinto) Tradition Inland or North Coast 3,000 B.C. 7,000 B.C. San Dieguito Tradition Great Basin Lakes 9,000 B.C. Ancient Coastal People ,? 25,000 B.C. -------------------------- Wisconsin Glacial Age Asia & Bering Bi -Polar Tool Tradition Straits 80,000 B.C. Figure 5. Cultural patterns in the central Riverside County area. The Shoshonean Tradition appears as one or more migrations of desert peoples who moved towards the coast and developed diverse economies of hunting, gathering, and coastal fishing. People of this tradition occupied the villages along the northern and west- ern beach lines of prehistoric Lake Cahuilla. Archaeological sites of this tradition are very numerous and indicate the presence of many populated villages and specialized satellite camps. The cultural remains vary and reflect the particular activities pursued at each loca- tion. Characteristic items are small arrow points, shell ornaments, and mortars for process- ing acorns. Pottery became a part of this tradition in the Riverside County area. The diversity and flexibility in economies seemingly led to population increases, enhanced trade, and elaborations in social and political structures, which, in turn, resulted in increas- ingly ggreater complexities in archaeological remains. Shoshonean groups, such as the Cahuilla pear to have surged northward and westward as the resources of the vast prehistori appear c Lake Cahuilla dried up about A.D. 1,500. Even Shoshonean settlements as far north as the Santa Ana River were affected. The Hakatayan Tradition emerged along the Colorado River as a society of horticulturists and food gathers. It spread westward into the deserts and into coastal San Diego County, and it may have assimilated with the earlier Encinitas Tradition. The tradition is archaeo- logical characterized by the manufacture of pottery, but it also includes small arrow points and numerous other tools. Some early sites of the tradition occur in Riverside County, but south of Riverside County there are numerous late Hakatayan Tradition villages and satel- lite activity camps with various arrays of equipment, ornaments, and ceramics. Hakatayan peoples probably occupied the southeastern shoreline of prehistoric Lake Cahuilla. The diverse patterns of the seasonal economies with people moving to special activity camps from central villages remain challenging to reconstruct, as are the social interactions with neighboring Shoshonean Tradition peoples. The Explorer Incidents of the historic period are principally the Coronado expedition and the Cabrillo exploration of 1540 and 1542. The era ends with the exploration party of Portola in 1769 -70 which founded the coastal missions, the 1772 Fages reconnaissance through the region, and the four parties led by Anza in 1774 -76 establishing a trail across the territory from Arizona to the coast. The full impact of these events on native society and the archaeological record has received scant attention. The Colonial Spanish Mission Era introduced a Hispanic cultural tradition to the region with adobe architecture, agriculture, cattle herding, and new crafts. This historic contact greatly reduced the native Hakatayan and Shoshonean populations, and subsequent ac- counts of the native lifeways are often incomplete or greatly altered. The Mexican Ranch Pastoral Era expanded Hispanic cattle raising and ranch settlements throughout the southern California. Investigations at rural ranch sites reflect diverse populations and demonstrate a mixture of local crafts items mixed with worldly imported goods. . The Landless Indian Era reflects the adjustments of shifting settlements and economic pursuits of disrupted native populations following the incursion of Hispanic and An to ranching. Although historically documented, only a few local archaeological sites of this era have been studied. The Indian Reservation Era is marked with the formal creation of reservations. These lands have provided bases for the continuation into the present of traditional customs. ' For the ongoing American Development Era with its poly- ethnic society, no single descrip- tion presents a comprehensive depiction. Rapidly changing cultural patterns linked into ' expanding world- system economies characterize this era. 1 12 ' CHAPTER V RESULTS OF THE INVESTIGATION This survey investigation found no archaeological sites or historical landmarks to be locat- ed on the property of the Green Specific Plan. A review of previously filed records, a field reconnaissance, a request of local Native American views, and a review of the regional literature all were negative.. A number of archaeological sites previously have been recorded in the nearby area, and ' one new archaeological site located just beyond the property boundary was recorded during the field reconnaissance. All of the previously recorded sites in the region are distant from the project area by one - quarter mile or more. These sites are summarized below. `■ Previous Archaeological Investigations There are reports on file for thirteen archaeological investigations that have been conduct- ed for the region in a one mile radius of the project area, and 42 archaeological site loca- tions have been recorded in this nearby region. A bibliographical listing of these regional ' survey reports is provided as Appendix A. Only about half of the land within a mile radius of the project actually has been surveyed for archaeological resources. The recorded archaeological sites known in the nearby region are listed in Table 1. Over- `' all, they suggest the following local picture of prehistoric land -use and settlement patterns. This region was intensively occupied in the last millennium, as pottery is typically found in the local habitation sites. This was the period when prehistoric Lake Cahuilla filled the ' basin and thereafter. A number of settlements existed along the beach line. Many other seasonal habitation sites are located within the desiccated lake basin and were occupied after the lake evaporated. Many of the camps and other sites located well above the old beach line also have pottery and could have been occupied either during the lake's t presence or since its desiccation. No sites representing more ancient traditions have been recognized in the nearby area. =� A Newly Recorded Archaeological Site. RIV -5324 ' During the field reconnaissance one new archaeological site was located and recorded just outside the boundary of the tract. This site was an isolated bedrock milling slick with no associated archaeological materials or midden deposit. This isolated feature was located on a flat rock at the edge of the fan at the base of a steep ridge. This site occurred where the alluvial fan extends into a cove in the ridge and is approximately 350 feet east of the Green property. This site was mapped, fully recorded, and photographed. The site forms have been filed with the State's California Archaeological Inventory where the location has been officially designated as the RIV -5324 site. (A copy of the site documentation is t provided as Appendix D; in keeping with State policy, this appendix with the mapped site location is NOT FOR PUBLIC DIS7RMU770N. ) G The RIV -5324 site is an isolated bedrock milling feature and, it should be considered as a non - unique archaeological resource. It is similar to other isolated milling stations in the nearby region, such as the RIV -3872 and the RIV -3873 sites. Still other such bedrock milling features have been recorded at the nearby RIV -1331 and RIV -3778 sites. �' 13 Table 1. Archaeological Sites Recorded near the Project Area. RIV -37 Village Pottery, petroglyphs, with RIV- 193/1715 RIV -193 Petroglyphs Ritual to RIV - 37/1715 settlement RIV -273 Village Cremations, lithic tools, pottery, RIV -369 Village House rings, fire pits, pottery, groundstone, etc. RIV -626 Rock cairns Possibly solstice rite site RIV -627 Rock cairns Three isolated rock cairns RIV -764 Village Pottery sherds, lithic tools RIV -1331 Rockshelter camp Pottery, milling features, food bone, stone tools RIV -1332 Rockshelter cache 011a, wooden items RIV -1334 Seasonal habitation Pottery scatter, along old beach line RIV -1337 Seasonal habitation Cremation, pottery sherds RIV -1338 Seasonal habitation Lithic tools, pottery RIV -1339 Seasonal habitation Pottery, house ruins, lithic debitage RIV-1340 Seasonal habitation Pottery, groundstone, lithic debitage RIV -1341 Seasonal habitation Pottery sherds, hearth RIV -1342 Seasonal habitation Pottery sherds RIV -1343 Seasonal habitation Pottery sherds, hearth RN -1344 Seasonal habitation Pottery sherds, hearth, lithic debitage RIV-1346 Pot drop Pottery sherds RIV -1347 Seasonal habitation Pottery sherds, hearth RIV -1348 Rockshelter camp Pottery sherds RIV -1349 Rockshelter camp Pottery, lithic tools, food bone RIV -1350 Rockshelter camp Pottery sherds, metate, olla RIV -1351 Seasonal habitation Pottery sherds, lithic debitage RIV -1715 Village Pottery sherds, with RIV- 37/193 RIV -1716 Pot drop Pottery sherds RIV -1717 Pot drop Pottery sherds RIV -1718 Seasonal habitation Pottery, chipped stone tools RIV -3209 Toro Cemetery Fenced graves, cremations, pottery RIV -3872 Milling station Isolated milling slicks with mano RIV -3873 Milling station Isolated milling slick RIV -3874 Pot drop Pottery sherds RIV -3875 Pot drop Pottery sherds RIV -3876 Pot drop Pottery sherds RIV -3877 Seasonal habitation Pottery, debitage, groundstone, bead RIV -3878 Seasonal habitation Site Pottery, milling slick, food bone RIV -3879 Milling station Two bedrock slicks RIV -3880 Seasonal habitation site Pottery sherds stone tools, food bone RIV -3881 Seasonal habitation site Pottery, lithic debitage RIV -5212 Seasonal habitation Pottery sherds, food bone RIV -5213 Seasonal habitation Pottery sherds RIV -5214 Pot drop Pottery sherds 14 CHAPTER VI CONCLUSIONS AND PLANNING CONSIDERATIONS No cultural resources were found to exist on the approximately 112 acres proposed for development as the Green Specific Plan. A review, of previously filed records and land- mark registries, a field reconnaissance, a request of local Native American views, and a ' review of the regional literature found no archaeological sites or historical landmarks asso- ciated with the property. There are a goodly number of previously recorded archaeological sites within the nearby ' region. It is probable that this Green property was visited and utilized for gathering and hunting by people from nearby settlements in prehistoric times. However, it was never utilized intensively enough to produce a permanent archaeological record on the land, or ' else such evidence has been obliterated by subsequent erosion. It is concluded that the development of the property in the Green Specific Plan will have ' no direct impact on any known cultural resources. It is proposed, therefore, that no further specific planning considerations for known cultural resources are warranted to mitigate the direct impacts of the development. ' During the field reconnaissance, one archaeological site was located just outside the boundary of the project property and could be indirectly impacted by local developments. This site is an isolated bedrock milling station. This location is a non - unique archaeologi- cal resource similar to other bedrock milling features in the region. For planning purposes ' under the California Environmental Quality Act, this site should be considered as non - unique and require no further planning considerations. "A nonunique archaeological resource need be given no further consideration, other than simple recording of its exist- ' ence by the lead agency if it so elects" (P.R.C. 21083.2). The site recordation has been accomplished as part of this survey undertaking, and copies of the recordation have been filed with the State's California Archaeological Inventory. Is it proposed, therefore, that no ' further specific planning considerations to mitigate any direct or indirect impacts to the RIV -5324 site are warranted. Indirect impacts from the proposed development project upon cultural resources in the ' surrounding region are not anticipated but are possible. Although there are no other known archaeological sites recorded within one - quarter mile, unrecognized and unrecord- ed sites may still exist, particularly in areas yet to be surveyed. However, nearby properties ' are not subject to effective protective measures in connection with the presently proposed project. It is proposed, therefore, that no further specific planning considerations to mitigate such indirect impacts are warranted. There are a number of recorded archaeological sites nearby, so this region is considered a sensitive area for archaeological resources. Under CEQA (P.R.C. 21083.2i), the City "may make provisions for archaeological sites accidentally discovered during construction." The ' City may require that a trained archaeological monitor be present during the grading operations to evaluate and coordinate the recovery of any archaeological resources uncov- ered. � J 15 APPENDIX A RECORD FILE SEARCH REPORT, and BIBLIOGRAPHY OF REGIONAL ARCHAEOLOGICAL INVESTIGATIONS Dear Dr. Chase: We received your request on March 28, 1994 for a cultural resources records search for the project designated Travertine Point located in Sections 4, 5, and 33, T.6 and 7S, R.7E, SBBM, near Toro Canyon in Riverside County. We have reviewed our site records, maps, and manuscripts against the location map you provided. Our records indicate that a cultural resources survey has been conducted on a portion of the project area. Twelve cultural resources survey reports are available that are on, adjacent to, or within a one-mile-radius of the project area. These reports are listed on the attachment entitled "Archeological Reports ". The KEYWORD section of each citation lists the geographic area, quad name, listing of trinomiai:: (when identified), report number in our manuscript files (MF #), and the number of pages per report. You received copies of all of the reports on March 31, 1,994 except for MF #3652 which is enclosed as requested. MF #4073 is not listed on the "Archaeological Reports" because the report was just recently received and the information has not been entered into the NADB file. Following is the listing for MF #4073 as it will appear when entered into the NADB file: Schaffer, Jerry, Drew Pallette, and Lowell J. Bean 1993 Archaeological Investigations of Two Lake Cahuilla Campsites Near Toro Canyon, Riverside County, California. Brian F. Mooney Associates. Submitted to private. Unpublished report on file at the Eastern Information Center, U. C. Riverside, CA 92521. Keywords: MF #4073 (6), 100 PP (7), No acres surveyed.- test phase (4), Martinez Mtn 7.5' q!!ad (4), Coachella Valley (4), Northern Pennisular Ranges (4), CA -RIV -7331 (8), CA -RIV -1349 (8) Nine archaeological sites are known within the project boundaries and our records indicate that 31 archaeological sites have been recorded within a one mile radius of the project area. Copies of the site records are included for your study needs. California Eastern Eastern Information Center Department of Anthropology Archaeological Information University of California Inventory -- Center INYO Riverside. CA 92521 MONO 101 ) 787-5745 RIVERSIDE I_ April 12, 1994 :w RS #1570 1 Paul G. Chase Director Archaeology The Keith Companies 2955 Red Hill Avenue Costa Mesa, CA 92626 ' Re: Project No. 4568 Dear Dr. Chase: We received your request on March 28, 1994 for a cultural resources records search for the project designated Travertine Point located in Sections 4, 5, and 33, T.6 and 7S, R.7E, SBBM, near Toro Canyon in Riverside County. We have reviewed our site records, maps, and manuscripts against the location map you provided. Our records indicate that a cultural resources survey has been conducted on a portion of the project area. Twelve cultural resources survey reports are available that are on, adjacent to, or within a one-mile-radius of the project area. These reports are listed on the attachment entitled "Archeological Reports ". The KEYWORD section of each citation lists the geographic area, quad name, listing of trinomiai:: (when identified), report number in our manuscript files (MF #), and the number of pages per report. You received copies of all of the reports on March 31, 1,994 except for MF #3652 which is enclosed as requested. MF #4073 is not listed on the "Archaeological Reports" because the report was just recently received and the information has not been entered into the NADB file. Following is the listing for MF #4073 as it will appear when entered into the NADB file: Schaffer, Jerry, Drew Pallette, and Lowell J. Bean 1993 Archaeological Investigations of Two Lake Cahuilla Campsites Near Toro Canyon, Riverside County, California. Brian F. Mooney Associates. Submitted to private. Unpublished report on file at the Eastern Information Center, U. C. Riverside, CA 92521. Keywords: MF #4073 (6), 100 PP (7), No acres surveyed.- test phase (4), Martinez Mtn 7.5' q!!ad (4), Coachella Valley (4), Northern Pennisular Ranges (4), CA -RIV -7331 (8), CA -RIV -1349 (8) Nine archaeological sites are known within the project boundaries and our records indicate that 31 archaeological sites have been recorded within a one mile radius of the project area. Copies of the site records are included for your study needs. Paul G. Chase April 12, 1994 Page 2 The above information is reflected on the enclosed map. Areas that are shaded in yellow indicate areas that have been surveyed. Numbers in pencil indicate the report number in our manuscript files (MF #). Areas in red show the location of cultural resources, and their corresponding numbers in black represent the state trinomial. In addition to the California Archaeological Inventory, the following were reviewed: The National Register of Historic Places, Vol. I and II, and subsequent Federal Register Listings: None of the properties or sites are'listed. National Register Determinations of Eligibility (listed through August 1993): None of the properties or sites have been evaluated for eligibility. A review of early USGS topographic maps of the area, Palm Desert 15' (1959), and the General Land Office plat maps T.6S., ME., (1856, 1903) and T.7S., ME., (1904, 1909) indicated no historic structures present.. Please note the possible aboriginal trail marked "Road" running 1.5 miles east of your project area on the 1856 GLO Plat map. Copies of the maps are included for your information. This statement does not constitute a negative declaration of impact. This statement reports only known archaeological materials on or in the vicinity of the property in question. The presence of cultural resources on the property cannot be ruled out until a systematic survey is conducted. For further information on historic resources, please contact Diana Seider, Riverside County Historian, at (909) 275 -4310. As the Information Center for Riverside County, it is necessary that we receive a copy of all archaeological reports and site information pertaining to these counties in order to maintain our map and manuscript files. Site location data provided with this records search are not to be used for reports unless the information is within the project boundaries. This information is confidential. Sincerely, Kyle Moffit Information Officer enclosures - -------------------------------------------------------------- - - - - -- -- - - - - -- - - - - -- ARCHEOLOGICAL REPORTS NADB /Query Printed: 04/06/94 Page: 001 ' WILKE, PHILIP J. AND DOUGLAS FAIN 1972 AN ARCHAEOLOGICAL CUCURBIT FROM COACHELLA VALLEY. JOURNAL OF CALIFORNIA AND GREAT BASIN ANTHROPOLOGY, 1(1):110 -113. Keywords: 4 PP (7), COACHELLA VALLEY (4), MF #0063 (6), MARTINEZ MTN. 7.5' QUAD (4), CA -RIV -1331 (8) WEAVER, RICHARD 1975 ARCHAEOLOGY OF THE TAHOUITZ REGIONAL PARK "C ", PALM SPRINGS, CALIFORNIA. AUTHOR(S). SUBMITTED TO NA. UNPUBLISHED REPORT ON FILE AT EASTERN INFORMATION CENTER, U.C. RIVERSIDE, CA 92521. ' Keywords: 11 PP (7), 30 ACRES SURVEYED (4), COACHELLA VALLEY (4), MF #0170 (6), NO RESOURCES (8), PALM SPRINGS 7.5' QUAD (4) ------------------------------------------------------- SCIENTIFIC RESOURCE SURVEYS, INC. 1979 ARCHAEOLOGICAL SURVEY REPORT ON THE O'NEAL PROPERTY, COACHELLA VALLEY, RIVERSIDE COUNTY, CALIFORNIA. AUTHOR(S). SUBMITTED TO PRIVATE. UNPUBLISHED REPORT ON FILE AT EASTERN INFORMATION CENTER, U.C. RIVERSIDE, CA 92521. Keywords: 8 PP (7), 893 ACRES SURVEYED (4), CA -RIV -1718 (8), CA -RIV -1717 (8), CA -RIV -1716 (8), CA -RIV -1715 (8), CA -RIV -0193 (8), COACHELLA VALLEY.(4), LA QUINTA 7.5' QUAD (4), MF 00632 (6), MARTINEZ MTN. 7.51'QUAD (4), VALERIE 7.5' QUAD (4) --------------------------------------------------------------------------------------------------------------- W1LKE, PHILIP J. 1980 AN ARCHAEOLOGICAL ASSESSMENT OF PROPOSED WASTEWATER TREATMENT PLANT IN SECTION 34, T6S, R7E, S88M, IN THE COACHELLA VALLEY, RIVERSIDE COUNTY, CALIFORNIA. ARCHAEOLOGICAL RESEARCH UNIT, U.C. RIVERSIDE. SUBMITTED TO PRIVATE. CONTRACT NO. ARU #492. UNPUBLISHED REPORT ON FILE AT EASTERN INFORMATION CENTER, U.C. RIVERSIDE, CA 92521 Keywords: 18' PP (7), 97 ACRES SURVEYED (4), CA -RIV -1339 (8), CA- RIV -1343 (8), CA- RIV -0273 (8), COACHELLA VALLEY (4), MF #0867 (6), VALERIE 7.51 QUAD (4) --------------------------------------------------------------------------------------------------------------- SWENSON, JAMES D. ' 1981 AN ARCHAEOLOGICAL ASSESSMENT OF THE PROPOSED WASTEWATER TREATMENT PLANT SITE IN SECTION 33 AND 28, T6S, R7E, SBBM, IN THE COACHEL!A VALLEY, RIVERSIDE COUNTY, CALIFORNIA. ARCHAEOLOGICAL RESEARCH UNIT, U.C. RIVERSIDE. SUBMITTED TO PRIVATE. UNPUBLISHED REPORT ON FILE AT EASTERN INFORMATION CENTER, U.C. RIVERSIDE, CA 92521 Keywords: 100 ACRES SURVEYED (4), 9 PP (7), CA- RIV -1346 (8), CA -RIV -1347 (8), COACHELLA VALLEY (4), MF #1334 (6), MARTINEZ MTN. 7.51 QUAD (4) ARCHEOLOGICAL REPORTS WADS /Query Printed: 04/06/94 Page: 002 PARR, ROBERT E. 1985 AN ARCHAEOLOGICAL ASSESSMENT OF A PROPOSED WASTEWATER TREATMENT PLANT SITE AND PIPELINE ALIGNMENT, LA ' QUINTA AREA OF RIVERSIDE COUNTY, CALIFORNIA. ARCHAEOLOGICAL RESEARCH UNIT, U.C. RIVERSIDE. SUBMITTED TO PRIVATE. CONTRACT NO. ARU #805. UNPUBLISHED REPORT ON FILE AT EASTERN INFORMATION CENTER, U.G. RIVERSIDE, CA 92521 ' Keywords: 12 PP (7), 800 ACRES SURVEYED (4), CA -RIV -1180 (8), COACHELLA VALLEY (4), INDIO 7.51 QUAD (4), LA QUINTA 7.5' QUAD (4), MECCA 7.51 QUAD (4), MF #2103 (6), VALERIE 7.5' QUAD (4) ' MCCARTHY, DANIEL F. 1987 AN ARCHAEOLOGICAL ASSESSMENT OF THE PROPOSED ELECTRIC LINE EXTENSION ALONG MONROE STREET, TORRES-MARTINEZ INDIAN RESERVATION, RIVERSIDE COUNTY, CALIFORNIA. ARCHAEOLOGICAL RESEARCH UNIT, U.C. ' RIVERSIDE. SUBMITTED TO PRIVATE. CONTRACT NO. ARU #891. UNPUBLISHED REPORT ON FILE AT EASTERN INFORMATION CENTER, U.C. RIVERSIDE, CA 92521 Keywords: 35 ACRES SURVEYED (4), 7 PP (7), CA -RIV -3209 (8), COACHELLA VALLEY (4), MF #2327 (6), VALERIE 7.5, QUAD (4) --------------------------------------------------------------------------------------------------------------- WESTEC SERVICES, INC. 1987 CULTURAL RESOURCE INVENTORY FOR RANCHO LA QUINTA. AUTHOR(S). SUBMITTED TO PRIVATE. UNPUBLISHED REPORT ON FILE AT EASTERN INFORMATION CENTER, U.C. RIVERSIDE,. CA 92521. Keywords: 1272 ACRES SURVEYED (4), 23 PP (7), CA -RIV -1343 (8), CA-RIV-1340 (8), CA -RIV -1717 (8), CA -RIV -0193 (8), CA -RIV -1716 (8), CA- RIV -0273 (8), CA- RIV -0273 (8), MARTINEZ MTN. 7.51 QUAD (4), LA QUINTA 7.51 QUAD (4), MF #2470 (6), VALERIE 7.51 QUAD (4), YES RESOURCES (8) --------------------------------------------------------------------------------------------------------------- ARKUSH, BROOKE 1990 AN ARCHAEOLOGICAL ASSESSMENT OF 1280 ACRES OF LAND LOCATED SOUTH OF INDIO-IN CENTRAL RIVERSIDE COUNTY, CALIFORNIA. ARCHAEOLOGICAL RESEARCH UNIT. SUBMITTED TO PRIVATE. CONTRACT NO. ARU #1069. UNPUBLISHED REPORT ON FILE AT EASTERN INFORMATION CENTER, U.C. RIVERSIDE, CA 92521 Keywords: MF #2961 (6), 42 PP (7), 1280 ACRES SURVEYED (4), COACHELLA VALLEY (4), MARTINEZ MTN. 7.5' QUAD (4), VALERIE 7.5' QUAD CO, CA -RIV -3872 (8), CA- RIV -3873 (8), CA -RIV -3874 (8), CA -RIV -3875 (8), CA-RIV -3876 (8), CA- RIV-3877 (8), CA- RIV-3878 (8), CA-RIV-3879 (8), CA- RIV-3880 (8), CA- RIV-3881 (8) KELLER, JEAN A. 1991 AN ARCHAEOLOGICAL ASSESSMENT OF COMPREHENSIVE GENERAL PLAN AMENDMENT 347. AUTHOR. SUBMITTED TO PRIVATE. UNPUBLISHED REPORT ON FILE AT EASTERN INFORMATION CENTER, U.C. RIVERSIDE, CA 92521. Keywords: MF #3652 (6), 15 PP (7), 5 ACRES SURVEYED (4), MARTINEZ 7.5' QUAD (4), NO RESOURCES (8), COACHELLA VALLEY (4) �l ARCHEOLOGICAL REPORTS WADS /Query Printed: 04 /06/94 Page: 003 ' MASON, ROGER D. 1993 CULTURAL RESOURCES SURVEY FOR "THE QUARRY" PROJECT, CITY OF LA QUINTA, RIVERSIDE COUNTY, CALIFORNIA. ' THE KEITH COMPANIES. SUBMITTED TO PRIVATE. UNPUBLISHED REPORT ON FILE AT EASTERN INFORMATION CENTER, U.C. RIVERSIDE, CA 92521. Keywords: MF #3919 (6), 7 PP. (7), 360 ACRES SURVEYED (4), COACHELLA VALLEY (4), LA QUINTA 7.5' QUAD. (4), MARTINEZ MTN. 7.5' QUAD. (4), CA-RIV -626 (8), CA-RIV-627 (8) I APPENDIX B LETTER OF INQUIRY TO NEARBY TORRES- MARTINEZ TRIBAL COUNCIL I I ® THE KEITH COMPANIES 13 June 1994 Mary E. Belardo, Chairperson Tones - Martinez Tribal Council c/o Torres- Martinez Tribal Office 66 -725 Martinez Road. Thermal, California 9:.274 Re: Green Property TKC #12460 Dear Chairperson Belardo: The Keith Companies is preparing a cultural resources assessment report on a proposed land development project on the Green property in the local area. The City of La Quinta will be reviewing this planning report, under the California Envi- ronmental Planning Act. The project area is indicated on the attached map copied from the USGS Martinez Mountain quad map. No significant cultural sites have been recognized on this property as yet. A review 3' of previously filed archaeological site records has identified no recorded sites there. An intensive field reconnaissance of the area is in progress. If you are aware of any special sites of Native American concern associated with this ` property, your counsel would be appreciated so that they may be addressed within the planning process. i if J171C -1 'YULLiJ, Yaul G. Chace Director of Archaeology PGC:bab natamrevlet (714) 668.7000 2995 Red Hill Avenue. Costa Mesa. CA 92626 Planning Engineering Environmental Services Landscape Architecture Land Surveying Public Works Water Resources APPENDIX C RESUME OF PRINCIPAL ARCHAEOLOGIST PAUL G. CHACE, Ph.D., SOPA ' Director of Archaeology ITechnical Services • Archaeological Investigations and Reports ' • Historic Landmark Assessments • Federal 106 and State CEQA Compliance • Heritage Research and Planning Experience Dr. Chace has 16 years experience directing archaeological programs serving the cultural resource management needs of private developers and government agencies. Prior to joining The Keith Companies, Dr. Chace operated an independent archaeological planning firm, serving as the Principal Investigator and organizing archaeological and historical assessments and legal compliance components for land development projects throughout southern California. Dr. Chace has conducted the archaeological programs required for the Valley Center sewer project, for the Valley Center sewer project, for the Las Montanas resort and housing subdivision in San Diego County, for land subdivisions in Riverside, San Diego,- and Los Angeles Counties for General Plan amendments in San Diego County, for Redevelopment Agency projects in the Cities of Banning and San Buenaventura, and for numerous similar projects. His technical reports and management recommendations, addressing the legal aspects of both CEQA and Federal requirements, have been prepared for the planning, review, and permit processes of various governmental agencies, including the State Office of Historic Preservation, the Water Resources Control Board, and the Coastal Commission, plus various counties and cities. For documentation of historical landmarks and heritage sites, Dr. Chace has assessed historic buildings near Lake Elsinore for a Bureau of Reclamation project. For the Bureau of Land Management, he directed the archaeology investigation and site stabilization of the Army's 1860s Fort Piute which protected the old southern desert road into California. At the 1880s Sepulveda Building in Los Angeles' El Pueblo State Park, he directed the archaeological component study for the building restoration and Historic Structure Report. Dr. Chace also has published scholarly descriptions of historic Chinese temples and Chinese community festivals in California. Dr. Chace is a past- president of the Society for California Archaeology and a member of the Society of Professional Archaeologists. In 1982 -1984 he served on the State Legislature's California Heritage Preservation Task Force. Education • Ph.D., University of California, Riverside 11 0 M.A., State University of New York, Oneonta • B.A., California State University, Long Beach continued ... N -56 -93 PAUL G. CHACE, Ph.D., SOPA Director of Archaeology '. Certifications • Certified, 1977, Society of Professional Archaeologists (SOPA) ' • Qualified Archaeologist, for Orange County, San Diego County, and other southern California city and county agencies • Certified Historian #528, 1986, California Council for the ' Promotion of History (CCPH) Affiliations • Society of Professional Archaeologists • 'Society for American Archaeology • American Anthropological Association • Pacific Coast Archaeological Society • Society for California Archaeology • Society for Historical Archaeology • California Council for the Promotion of History • Chinese Historical Society of Southern California Publications Dr. Chace has numerous publications on archaeology, CRM, and heritage; these include: "The Archaeology of 'Cienaga,' the Oldest Historic Structure on the Irvine Ranch. Pacific Coast Archaeological Society Quarterly 5(3):39 -55, 1969. "Biological Archaeology of Some Coastal Middens, Orange County, California." Pacific Coast Archaeological . Society Quarterly 5(2):64 -77, 1969. "The Buck Gully #2 Site (Ora -89), the Archaeology of a Late Horizon Coastal Site in Orange County, California." Pacific Coast Archaeological Society Quarterly 7(4):1-44 (with Duane Hafner and others) "An Archaeological Survey of the Fuquay Ranch, Evidence of Hakatayan Tradition Land Use is the Southern Peninsular Range, San Diego County." Pacific Coast Archaeological Society 16(3):1 -36, 1980. r i1The Kelly Site Complex: An Inland Encinitas Tradition Settlement in San Diego County." Pacific Coast Archaeological Society Quarterly 26(1):42 -59, 1990. (with Dr. Mark Sutton) ' "Easement as Mitigation." Society for California Archaeology Newsletter 12(3):15 -16, 1978. "Perspectives on Archaeological Site Capping." Contract Abstract and CRM Archaeology 3(1):41 -42, 1982. �1 "Overseas Chinese Ceramics.". In, The Changing Faces of Main Street, pp. 509 -530. The Redevelopment Agency of the City of San Bueaventura, 1976. The Oldest Chinese Temples in California, A Landmarks Tour." Gum Saan Journal 14(1):1 -19 1991. �la�ch 1993 '' N -56-93 TN /City of La Quinta TTM 33444 EA/8.24.05 Technical Reports Geotechnical Investigation Residential Subdivision — Green Property SWC Quarry Ranch Road and Jefferson Street La Quinta, California Prepared by Sladden Engineering 39 -725 Garand Lane, Suite G Palm Desert, CA 92211 January 26, 2005 GEOTECHNICAL INVESTIGATION RESIDENTIAL SUBDIVISION — GREEN PROPERTY ,SWC QUARRY RANCH ROAD AND JEFFERSON STREET LA QUINTA, CALIFORNIA - Prepared By- Sladden Engineering 39 -725 Garand Lane;'Suite G Palm Desert, California 92211 (760) 772 -3893 1 1 :S1ad de nEn; in e t. ern g 6782 Stanton Ave., Suite A, Buena Park, CA 90621 (714) 523 -0952 Fax (714) 523 -1369 39 -725 Garand Ln., Suite G, Palm Desert, CA 92211 (760) 772 -3893 Fax (760) 772 -3895 January 26, 2005 DDC Desert Development, Inc. g 1 74 -001 Reserve Drive Indian Wells, California 92210 `1 ` Attention: Subject: Mr. Tom Cullinan Geotechnical Investigation Project: Proposed 176 Lot Residential Subdivision — Green Property SWC Quarry Ranch Road and Jefferson Road La Quinta, California Project No. 544 -4769 05 -01 -075 Presented herewith is the report of the Geotechnical Investigation performed on the subject site located at the southwest corner of Quarry Ranch Road and the future southern extension of Jefferson Street in the City of La-Quinta, California. The investigation was performed in order to provide recommendations for site preparation and to assist in foundation design for the proposed residential development and the related site improvements. E' This report presents the results of our field investigation and laboratory testing along with conclusions ! and recommendations for foundation design and site preparation. This report completes our original scope of services as outlined in our proposal dated November 8, 2004. We appreciate the opportunity to provide service to you on this project. If you have any questions regarding this report, please contact the undersigned t;. Respectfully submitted, SLADDEN ENGINEE ING 1' r fv✓ Brett L. Anderson E.' Principal Engineer SER/lh 6 i{ I€ 4�pFESS IC) O�PN R. byR�C C�y•�. z u m w m No. C 64276 Exp.6 /30/07 it \�yT CIVIC- �, FOFCAUF�P Copies: 6/DDC Desert Development, Inc. GEO^ECH`ICAL IN'E'^^G'^^IO'' PROPOSED 176LOT RESIDENTIAL SUBDIVISION -GR88N PROPERTY SWCQ}ARRY RANCH ROAD AND JEFFERSON-STREET | LA Q�}IyJIA,CALIFORNIA January 26, 2005 TABLE OF CONTENTS APPENDIX /\- Site Plan and Boring ., Field Exploration APPENDD{B - LabmratozyIeotReso]ts APPEKDD(C- 1997DBCSeismic Design Criteria !�� INTRODUCTION ___.____._____.____..__._.__-_--''----__.----_.-..._-.l , SCOPE OF WORK ..... ~.......................................................................................................... ................ PROJECT DESCRIPTION .................................................... GEOLOGY AND SEISMICM ......................................................................... ____—_'_- SUBSURFACE CONDITIONS -----'--'----'-------'----------.--_-'3 � LIQUEFACTION ....................................... ............................................................................................... 3 CONCLUSIONS AND RECOMMENDATIONS ------'-_-----'--'---..._.---_.3 Foundation Design _-_------_'_----------------_--.-----'-------4 Settlements ........................................................................................................................................ 5 Lateral � �*�/�o-.-----_''---''----'----_-----.----_-.---_---'.---- 6 RetainingVVaDy'--_'---'____--_---._----.--'----.'---.'--.--_-- S 1�U us9uExpansive Soiln -'------.--.---'_'------'---'_---'_-----.---__.__---6 ~~ Concrete '''-------'-----'---'--'-...'--''—'—'---------.-. 6 SolubleSulfates ................................. '----------------.--_.-----.----_.---- 6 � Tentative Pavement ------.------.-_-'_-- . �`,� ''---'._-.__---'----~ a�d Subsidence .---_---------.--------.--__—.---_-..--_-- 7 General Site -------..-------_-----.---------.--._-----.-. 7 1 . Site Clearing ............................................................................................................................. y 2. Preparation of Building and Foundation Areas ---'-'--'--'-------'----- 3. Placement of Compacted -------_-.---.--------.------.----- 8 4. Preparation of Slab and Pavement Areas ........................................................................... 8 5. Testing and ---------.---_--..-.-._-----.-------'_- 8 GENERAL---_---____________.___._________.__________ . APPENDIX /\- Site Plan and Boring ., Field Exploration APPENDD{B - LabmratozyIeotReso]ts APPEKDD(C- 1997DBCSeismic Design Criteria !�� January 26, 2005 =1- Project No. 5444769 05 -01 -075 INTRODUCTION This report presents the results of our Geotechnical Investigation performed in order to provide recommendations for site preparation and to assist in the design and construction of the foundations for the proposed residential buildings. The subject site is located at the southwest corner of Quarry Ranch Road and the future southern extension of Jefferson Street in the City of La Quinta, California. We expect that the proposed single - family residences will be of relatively lightweight wood -frame construction. The associated site improvements will include paved roadways, concrete driveways, walkways and patios, underground utilities, and landscape. areas. SCOPE OF WORK The purpose of our investigation was to determine certain engineering characteristics of the near surface soils on the site in order to develop recommendations for foundation design and site preparation. Our investigation included field exploration, laboratory testing, literature review, engineering analysis and the preparation of this report. Evaluation of hazardous materials or other environmental concerns was not within the scope of services provided. Our investigation was performed in accordance with contemporary geotechnical engineering .principles and practice. We make no other warranty , either express or implied. PROJECT DESCRIPTION The subject site is located at the southwest corner of Quarry Ranch Road and the future southern extension of Jefferson Street in the in the City of La Quinta, California. It is our understanding that the proposed project will consist of a 176 lot residential subdivision. It is our understanding that the proposed residential buildings will be of relatively lightweight wood -frame construction and will be supported by conventional shallow spread footings and concrete slabs on grade. The associated site improvements will include paved roadways, concrete driveways, walkways and patios, landscape areas and various underground utilities. The subject site is presently vacant and the ground surface is covered with scattered desert brush, short grass and weeds. The site is located within an alluvial valley and the eastern and western site boundaries consist of steep natural rock hillsides associated with the eastern foothills of the Santa Rosa Mountains. The Quarry at La Quinta development forms the northern property boundary. Sladden Engineering r i c' e' i s x January 26, 2005. -3- SUBSURFACE CONDITIONS Project No. 544 -4769 05 -01 -075 The soils underlying the site consist primarily of fine to course grained alluvial sands with gravel and scattered cobbles.. Alluvial sands were the most prominent soils encountered within our exploratory borings. The native alluvial sands encountered near the existing ground surface appeared somewhat loose but sampler penetration resistance (as measured by field blowcounts) indicates that in -place density generally increases with depth. The site soils were found to be dry throughout the depth of our borings. Laboratory testing indicates that the surface soils consist primarily of alluvial sands. Expansion testing indicates an expansion index of 0 for a mixture of the near surface alluvial sands that are classified as "very low" expansion category soils in accordance with Table 18 -I -B of the 1997 Uniform Building Code. Groundwater was not encountered within our borings that extended to a maximum depth of 50 feet below the existing ground surface. LIQUEFACTION. Liquefaction occurs with sudden loss of soil.strength due to rapid increases in pore pressures within cohesionless soils as a result of repeated cyclic loading during seismic events. Several conditions must be present for liquefaction to occur including; the presence of relatively shallow groundwater, generally loose soils conditions, the susceptibility of soils to'liquefaction based upon grain -size characteristics and the generation of significant and repeated seismically induced ground accelerations. Liquefaction affects primarily loose, uniform grained cohesionless sands with low relative densities: In the case of this project site, one of the primary factors required for liquefaction to occur is absent. As previously indicated, groundwater was not encountered within our borings and groundwater is expected to be in excess of 100 feet below the existing ground surface throughout the site. CONCLUSIONS AND RECOMMENDATIONS Based upon our field investigation and laboratory testing, it is our opinion that the proposed residential development of the . subject site is feasible from a soil mechanic's standpoint provided that the recommendations included in this report are considered in building foundation design and site preparation. Due .to the somewhat loose and compressible condition of the near surface soils, remedial grading is recommended for the building areas. We recommend that remedial grading within the proposed building areas include the overexcavation and /or recompaction of the primary foundation bearing soils. Specific recommendations for site preparation are presented in the Site Grading section of this report. 4 Sladden Engineering i1 January 26, 2005 -4- Project No. 544 -4769 05 -01 -075 Based upon the depth to groundwater, the potential for liquefaction impacting the site during a major seismic event on the nearby San Andreas fault system is considered negligible. The remedial grading recommended for building areas will result in the construction of a uniform compacted soil mat beneath all structures that should limit potential seismically induced differential settlements. The site is located in one of the more seismically active areas in California. Design professionals should be aware of the site setting and the potential for earthquake activity during the anticipated life of the structures should be acknowledged. The accelerations that may be experienced on the site (as previously discussed) should be considered in design. The seismic provisions included in the Uniform Building Code for Seismic Zone 4 should be considered the minimum design criteria. Pertinent 1997 UBC Seismic Design Criteria is summarized in Appendix C. _. Caving did occur within our boring and the potential for caving should be expected .within deeper excavations. All excavations should be constructed in accordance with the normal CalOSHA excavation criteria. On the basis of our observations of the materials encountered, we anticipate that the near surface sandy silts and silty sands will be classified by CalOSHA as Type C. Soil conditions should be verified in the field by a "Competent person" employed by the Contractor. Settlements resulting from the anticipated foundation loads should be minimal provided that the recommendations included in this report are considered in foundation design and construction. The estimated ultimate settlements are calculated to be approximately 1 inch when usin g the recommended bearing values. As a practical matter, differential settlements between footings can be assumed as one- s half of the total settlement. The near surface soils encountered during our investigation were. found to be generally non - expansive. ' Laboratory testing indicated an Expansion Index of 0 for the near.surface alluvial sands that corresponds with the "very low" expansion category in accordance with UBC Table 18 -I -B. f The following recommendations present more detailed design criteria that have been developed on the basis of our field and laboratory investigation. The recommendations are based upon non - expansive soils criteria. E� Foundation Design: The results of our investigation indicate that either conventional shallow continuous footings or isolated pad footings that are supported upon properly compacted soils 4, may be expected to provide adequate support for the proposed structure foundations. Building pad grading should be performed as described in the Site Grading Section of this report to provide for uniform and firm bearing conditions for the structure foundations. i .' Sladden Engineering IJ anuar y 26, 2005 -5- Project No. 544 -4769 05 -01 -075 Footings should extend at least 12 inches beneath lowest adjacent grade. Isolated square or rectangular footings should be at least 2 feet square and continuous footings should be at least 12 inches wide. Continuous footings may be designed using an allowable bearing value of 1500 pounds per square foot (psf) and isolated pad footings may be designed using an allowable bearing pressure of 1800 psf. Allowable increases may be realized with increased footing size. Allowable increases of 200 psf for each additional 1 foot of width and 250 psf for each additional 6 inches of depth. The maximum allowable bearing pressure should be 2500 psf. The allowable bearing pressures are applicable to dead and frequently applied live loads. The allowable bearing pressures may be increased by 1/3 to resist wind and seismic loading. Care should be taken to see that bearing or subgrade soils are not allowed to become saturated from the ponding of rainwater or irrigation. Drainage from the building area, should be rapid and complete. The recommendations provided in the preceding paragraphs are based on the assumption that all footings will be supported upon properly compacted engineered fill soils. All grading should be performed under the testing and inspection of the Soils Engineer or his representative. Prior to the placement of concrete, we recommend that the footing excavations be inspected in order to verify that they extend into compacted soil and are free of loose and disturbed materials. Settlements: Settlements resulting from the anticipated foundation loads should be minimal provided that the recommendations included in this report are considered in foundation design and construction. The estimated ultimate settlements are calculated to be approximately one inch when using the recommended bearing values. As a practical matter, differential settlements between footings can be assumed as one -half of the total settlement. The potential liquefaction related settlements should also be considered in foundation design. Lateral Design: Resistance to lateral loads can be provided by a combination of friction acting at the base of the slabs or foundations and passive earth pressure along the sides of the foundations. A coefficient of friction of 0.42 between soil and concrete may be used with consideration to dead load forces only. A passive earth pressure of 275 pounds per square foot, per foot of depth, may be used for the sides of footings that are poured against properly compacted native or approved non - expansive import soils. Passive earth pressure should be ignored within the upper 1 foot except where confined (such as beneath a floor slab). Retaining Walls: Retaining walls may be necessary to accomplish the proposed construction. Lateral pressures for use in retaining wall design can be estimated using an equivalent fluid weight of 35 pcf for level free - draining native backfill conditions.. For walls that are to .be restrained at the top, the equivalent fluid weight should be increased to 55 pcf for level free - draining native backfill conditions. Backdrains should be provided for the full height of the walls. Madden Engineering January 26, 2005 I". Project No. 544 -4769 05 -01 -075 Expansive Soils: Due to the prominence of "very low" expansion category soils near the surface, the expansion potential of the foundation bearing soils should be considered in foundation or floor slab design. Because the recommended remedial grading will result in substantial removal and mixing of the surface soils, the expansion potential may change. Expansion potential should tbe reevaluated subsequent to rough grading and foundation and floor slab design should be based upon post - grading test results. Concrete Slabs -on- Grade: All surfaces to receive concrete slabs -on -grade should be underlain by a minimum compacted non - expansive fill thickness of 24 inches, placed as described in the Site Grading Section of this report. Where slabs are to receive moisture sensitive floor coverings or where dampness of the floor slab is not desired, we recommend the use of an appropriate vapor barrier or an adequate capillary break. Vapor barriers should be protected by sand in order to reduce the possibility of puncture and to aid in obtaining uniform concrete curing. Reinforcement of slabs -on -grade in order to resist expansive. soil pressures may not be necessary. However, reinforcement will have a beneficial effect in containing cracking due to concrete shrinkage. Temperature and shrinkage related cracking should be anticipated in all concrete s' slabs -on- grade. Slab reinforcement and the spacing of control joints should be determined b the P g 1 Y i Structural Engineer. Soluble Sulfates: The soluble sulfate concentrations of the surface soils were determined to be 33 parts per million (ppm). The use of Type V cement and specialized sulfate resistant concrete mix designs may be necessary. Soluble sulfate content of the near surface soils should be ` reevaluated after rough grading. Tentative Pavement Design: All paving should be underlain by a minimum compacted fill thickness of 12 inches (excluding aggregate base). This may be performed as described in the Site Grading Section of this report. R -Value testing was not conducted during our investigation but based upon the silty nature of the surface soils, an R -Value of approximately 60 appears appropriate for preliminary onsite pavement design. The following preliminary pavement section is based upon a design R -Value of 60. On -site roadways subjected to auto and light truck traffic (Traffic Index = 5.0) Use 3.0 inches of asphalt on 4.0 inches of Class 2 base material Sladden Engineering January 26, 2005 -7- Project No. 5444769 05 -01 -075 Aggregate base should conform to the requirements for Class 2 aggregate base in Section 26 of CalTrans Standard Specifications, January 1992. Asphaltic concrete should conform to Section 39 of the CalTrans Standard Specifications. The recommended pavement sections should be ' provided with uniformly compacted subgrade and precise control of thickness and elevations during placement. i. 11 Pavement design sections are tentative and should be confirmed at the completion of site grading when the subgrade soils are in- place. This should include sampling and testing of the actual . subgrade soils and an analysis based upon the specific traffic information Shrinkage and Subsidence: Volumetric shrinkage of the material that is excavated and replaced as controlled compacted fill should be anticipated. We estimate that this shrinkage should vary from 10 to 15 percent. Subsidence of the surfaces that are scarified and compacted should be between 1 and 2 tenths of a foot. This will vary depending upon the type of equipment used, the moisture content of the soil at the time of grading:and the actual degree of compaction attained. These values for shrinkage and subsidence are exclusive of losses that will occur -due to the stripping of the organic material from the site. General Site Grading: All grading should be performed in accordance with the grading ordinance of the City of La Quinta, California. The following recommendations have been developed on the basis of our field and laboratory testing and are intended to provide a uniform compacted mat of soil beneath the building slabs and foundations. 1. Site Clearing: Proper site clearing will be very important. Any existing vegetation, slabs, foundations, abandoned underground utilities or irrigation lines should be removed from the proposed building areas and the resulting excavations should be properly backfilled. Soils that are disturbed during site clearing should be removed and replaced as controlled compacted fill under the direction of the Soils Engineer. 2. Preparation of Building and Foundation Areas: In order to provide adequate and uniform bearing conditions, we recommend overexcavation throughout the proposed building areas. The building areas should be overexcavated to a depth of at least 2 feet below existing grade or 2 feet below the bottom of the footings, whichever is deeper. The exposed soils should then be scarified to a depth of 1 foot, moisture conditioned and recompacted to at least 90 percent relative compaction. The excavated material may then be replaced as engineered fill material as recommended below. Because the site soils are granular in nature we expect that compaction may be attained to a depth of 3 or 4 feet by watering and compacting with heavy grading equipment. If adequate compaction is attained overexcavation may not be necessary on non - transition building pads. Sladden Engineering . I January 26, 2005 M Project No. 5444769 05 -01 -075 3. .Placement of Compacted Fill:. Within the building pad areas, fill materials should be spread in thin lifts, and compacted at near optimum moisture content to a minimum of 90 percent relative compaction. Imported fill material shall have an Expansion.Index not exceeding 20. Because the deeper soils may be wet when excavated, some drying or stabilization should be expected. The wet soils removed during excavation should be dried back to near optimum moisture content or mixed with dry soils prior to placement as engineered fill material. The bottom of the excavations should be stable and unyielding prior to fill placement. The contractor shall notify the Soils Engineer at least 48 hours in advance of importing ' soils in order to provide sufficient time for the evaluation of proposed import materials. The contractor shall be responsible for delivering material to the site that complies with the project specifications. Approval by the Soils Engineer will be based upon material delivered to the site and not the preliminary evaluation of import sources. Our observations of the materials encountered during our investigation indicate that ' compaction within the native soils will be most readily obtained by means of heavy rubber tired equipment and /or sheepsfoot .compactors. A uniform and near optimum moisture content should be maintained during fill placement and compaction. 4. Preparation of Slab and Paving Areas: All surfaces to receive asphalt concrete paving or exterior concrete slabs -on -grade should be underlain by a minimum compacted fill thickness of 12 inches. This may be accomplished by a combination of overexcavation, scarification and recompaction of the surface, and.replacement of the excavated material as controlled compacted fill. Compaction of the slab and pavement areas should be to a minimum of 90 percent relative compaction. 5. Testing and Inspection: During grading tests and observations should be performed by the Soils Engineer or his representative in order to verify that . the grading is being performed in accordance with the project specifications. Field density testing shall be performed in accordance with applicable ASTM test standards. The minimum acceptable degree of compaction shall be 90 percent of the maximum dry density as obtained by the ASTM D1557 -91 test method. Where testing indicates insufficient density, additional compactive effort shall be applied until retesting indicates satisfactory compaction. Sladden Engineering January 26 2005 -9- i J y ' GENERAL Project No. 544 -4769 05 -01 -075 The findings and recommendations presented in this report are based upon an interpolation of the soil conditions between boring locations and extrapolation . of these conditions throughout the proposed building area. Should conditions encountered during grading appear different than those indicated in this report, this office should be notified. This report is considered to be applicable for use by DDC Desert Development, Inc. for the specific site and project described herein. The use of this report by other parties or for other projects is not authorized.. The recommendations of this report are contingent upon monitoring of the grading operations by a representative of Sladden Engineering. All recommendations are considered to be tentative pending our review of the grading operations and additional testing, if indicated. If others are employed to perform any soil testing, this office should be notified prior to such testing in order to coordinate any required site visits by our representative and to assure indemnification of Sladden Engineering. We recommend that a pre -job conference be held on the site prior to the initiation of site grading. The purpose of this meeting will be to assure a complete understanding of the recommendations presented in this report as they apply to the actual grading performed. Sladden Engineering January 26, 2005 -10- Project No. 5444769 05 -01 -075 REFERENCES ASCE Journal of Geotechnical Engineering Division, April 1974. Boore, Joyner and Fumal (1994) Estimation of Response Spectra and Peak Accelerations from North American Earthquakes, U. S. Geological Survey, Open File Reports 94127 and 93 -509. Finn, W. E. Liam, (1996) Evaluation of Liquefaction Potential for DifferentEarthquake Magnitudes and Site Conditions, National Center for Earthquake Engineering Research Committee. Joyner and Boore, (1998) Measurements, Characterization and Prediction of Strong Ground Motion, ASCE Journal of Geotechnical Engineering, Special Publication No.. 20. Lee & Albaisa (1974) "Earthquake Induced Settlements in Saturated Sands ". Seed and Idriss (1982) Ground Motions and Soil Liquefaction During Earthquakes, Earthquake Engineering Research Institute Monograph. Seed, Tokimatsu, Harder and Chung, (1985), Influence of S,PT Procedures in Soil Liquefaction Resistance Evaluations, ASCE Journal of Geotechnical Engineering, Volume 111, No. 12, December. Rogers, Thomas H., Geologic Map of. California, Santa Ana Map Sheet. Riverside County, 1984, Seismic Safety Element of the Riverside County General Plan Sladden Engineering APPENDIX A Site Plan Boring Logs APPENDIX A FIELD EXPLORATION For our field investigation, 12 exploratory borings were excavated on December 1 and December 3, 2004, using a truck mounted hollow stem auger rig (Mobile B -61) in the approximate locations indicated on the c.' site plan included in this appendix. Continuous log of the materials encountered were prepared on the site by a representative of Sladden Engineering. Boring logs are included in this appendix. ' Representative undisturbed samples were obtained within our boring by driving a thin - walled steel penetration sampler (California split spoon sampler) or a Standard Penetration Test (SPT) sampler with a ' 140 pound hammer dropping approximately 30 inches (ASTM D1586). The number of blows required to drive the samplers 18 inches was recorded (generally in 6 inch increments). Blowcounts are indicated on the boring log. E"1 The California samplers are 3.0 inches in diameter, carrying brass sample rings having inner diameters of 2.5 inches. The standard penetration samplers are 2.0 inches in diameter with an inner diameter of 1.5 inches. Undisturbed samples were removed from the sampler and placed in moisture sealed containers .' in order to preserve the natural soil moisture content. Bulk samples were obtained from the excavation spoils and samples were then transported to our laboratory for further observations and testing. I'' It it it ZZ TopoQuads Copyright m 1999 DeUrme Yarmouth, ME 04096 Source Data: USGS 1000 ft Scale:1 : 25,000 Detail: 13-0 Datum: WGS84 USGS Map Proposed Residential Subdivision Green Property North SWC Quarry Ranch Road & Jefferson Street La uint California Sladden Engineering Project Number: 544 -4769 Date: 1 -26 -05 11 1 ( {J1`5y L/J/�J �` � �,1 �(�•�, ,rJ J ��\ � , l� 5G1� \ _ s" �` °`:,.. 'I p n \ .. 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' �' -� •� ,4, t'•: \,: ;, r•., r „ ter,.- i_'"••. �i = - '`•Z�'' \r•'.-��: � �\ .�..�.'f 1 irJ:; —�I'T , \ 7!r' ...•. ,� —Y� : \.'`ki- -•I; — . c c1••.._ ��e .` :` ' "", �,`; •: ;\,. • ilJ 'i it : r. ._ � jt \ :1. - r:� ( r;::�/i , I �,.. `` l,'; f;, ��� e \�.�.9,- �•i•,� , �t�i __� �;-• � }� � \', �, . R } i �•O \lf '1 �J. •+ '::i �' •�.R 1_. J �� I i . I J , ii v1i \ \\\ l� O ]%IaatGae. rl;r � `•riff �.,�;, %�' >Yt_. `17 _ � ` - /',._... �•.- it �! 'MV `•, `,.. � \1•`\ J/�•� ..,_`!___ \. _•.•. ��'�1 `•• "�-1 it �% ,;•,.. ,_ : .�,; ^ `,� ... _ , , J,.. _. ,.�` •err.. % � .:- ,. --•• i i It it it ZZ TopoQuads Copyright m 1999 DeUrme Yarmouth, ME 04096 Source Data: USGS 1000 ft Scale:1 : 25,000 Detail: 13-0 Datum: WGS84 USGS Map Proposed Residential Subdivision Green Property North SWC Quarry Ranch Road & Jefferson Street La uint California Sladden Engineering Project Number: 544 -4769 Date: 1 -26 -05 11 1 ( {J1`5y L/J/�J �` � �,1 �(�•�, ,rJ J ��\ � , l� 5G1� \ _ s" �` °`:,.. 'I p n \ .. '•• .cg'r' ,_,x"i�'�:-' AVENUE � ,5fr, : �; '� .6< r �� f:rr' r>_'.l� •. -.' 1 \ . t . r ... ..:. O 1 17 . j l•\'...I .' R�_ ;�;: .�' -.?ir - _. 1 � �%'3s J � \P\ ` , ' =_h�os _a It .1 _ _ : /:. '; � 1 � . _ `.. ^ _ ' •1 • ...` \„__._ .I f % / ^ '�'t ' j OI 1: �7i' `,�� 'f 1 ` +I pI it - '�'• 'I�•�r , � • - /' \':: -'? 'I �� ^,:4f ,� (,r f � f'f:? .\ - ,. ,, `•a +;ysr r=� s �ll�.r. ...[:'_.: ..35£61 - .�:' ;;��. .r a �'' - -- I i• f:�• l ?:�7tily b Ir ,�{' I II�_::''•9!^ :J,1: 5cF i i:.� °+'•:.c . - ! - 4; ,\ i�� j, / + i . _ ��.._:'ti"i;. =�,.. tl�"6 + :.•'1 ��� \�. .j: ,'_J• �. 4 .' `' �• �:I i �' l�il , I Vii 1 � ., -: �/ 5'�p a4 i PO u '•5• ",, .. . �' ' +�.;. ,'',•f.,, : ?)• . � }. ' �' -� •� ,4, t'•: \,: ;, r•., r „ ter,.- i_'"••. �i = - '`•Z�'' \r•'.-��: � �\ .�..�.'f 1 irJ:; —�I'T , \ 7!r' ...•. ,� —Y� : \.'`ki- -•I; — . c c1••.._ ��e .` :` ' "", �,`; •: ;\,. • ilJ 'i it : r. ._ � jt \ :1. - r:� ( r;::�/i , I �,.. `` l,'; f;, ��� e \�.�.9,- �•i•,� , �t�i __� �;-• � }� � \', �, . R } i �•O \lf '1 �J. •+ '::i �' •�.R 1_. J �� I i . I J , ii v1i \ \\\ l� O ]%IaatGae. rl;r � `•riff �.,�;, %�' >Yt_. `17 _ � ` - /',._... �•.- it �! 'MV v •_ Sir..:'. `. �'` � � �'� , �;>�.,. •� ........... :..... • j �` t .•�� - \, � /° :J'. ; '.t "fir`;. �::A: _ emu,,: :: d., • t' ` , v.. ;;;'. , c. �J• •� •b' ;b.0 /. �:.t'I't.L: is j/ V � ty., .r���'��'�i�,_;W'``r ,�,':4+py"— .✓- '•��'.3•,3.. t,' • 1 \ ' I.A: `V�t'��: ���V � � ��' %�''\:4) ' :` . ':dry ��.. f '\ r; .,i, ,`,_•_ h•'s.�.( ?�;i.yy ,e.. .�. }r: Fr 1:' <;`s \ ���`. �'�•� 'J;;'i t:4:/ t �i %il .L a of •�I F y ': �', _ a . `S .' � ' �,'..:.,1 . . gs Os 7, X�� Approximate Bore Hole Locations 176 -Lot Green property ' SwC QumTr Ranch Rasa & reffmon Scat " La Quinta, Califomia Job No. .544-4769 Date: 02 -02 -05 Sladden Fagineetutg L 176 -Lot -Green Property SWC Quarry Ranch :Road & Jefferson Street Date: 12/1/2004 Borin 'No. 1 Job Number: 5444769 4. 0 o 3 ° c j Descri Description Remarks 0 Native Soil 5 18/50/45 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 6 Town in color - with Rock Fragments 10 9/14/17 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 5 Brown in color - with Rock Fragments - Refusal @ --12 Feet 15 20 25 30 California Split-spoon Sample Total Depth =I 21 edrock not encountered - _ Unrecovered Sample I Groundwater not encountered - Standard Penetration Test Sample 35 40 Note: The stratification lines represent the approximate - boundaries between the soil types; the transition may be _ gradual. 45 50 Sladden Engineering 17&Lot• Green Troperty •SWC Quarry •Ranch Road ..& Jefferson -Street Date: 12/1/2004 Boring No. 2 Job Number: 544 -4769 a 0 0 :It o y 3 a 8 M 2 U.. o Description rn° 4 — a Remarks 0 Native Soil 5 12/22/23 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 2. 7 Brown in color - _ with Rock Fragments J - [Refusal @ —9 Feet 10 15 20 - California Split-spoon Sample otal Depth = 9' 25 Bedrock not encountered - Unrecovered Sample I Groundwater not encountered - - Standard Penetration Test Sample 30 - Note: The stratification lines represent the approximate - boundaries between the soil types;4he transition may be _ gradual. 35 40 45 50 Sladden Engineering :176 -Lot Green Property SWC Quarry Ranch .Road & Jefferson Street Date: 12/1/2004 -Boring No. 3 Job Number: 5444769 • A o o C14 o 0 0 0 (� Description . r° o Remarks 0 Native Soil 5 10/17/17 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 7 Brown in color - with Rock Fragments 10 11/14/17 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 8 Town in color - with Rock Fragments L - efusal —12 Feet 15 - California Split -spoon Sample Total Depth =-12' - Bedrock not encountered 20 - Unrecovered Sample I Groundwater not encountered - Standard Penetration Test Sample 25 - Note: The stratification lines represent the approximate - boundaries between the soil types; the transition may be _ gradual. 30 35 40 45 50 Sladden Engineering •176 -Lot; Green =Property SWC Quarry Ranch 'Road..& Jefferson - Street Date: 12/1/2004 Boring No.4 Job Number: 544 -4769 4. 0 0 � a o N a a o o �j U pq Desmi tion Remarks 0 Native Soil 5 11/1924 Sample Not Recovered 10 [ 10/19/21 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 5 Brown in color - with Rock Fragments 15 6/1522 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 6 Brown in color - with Rock Fragments 20 23/36/41 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 6 Brown in color - with Rock Fragments 25 30 California Split -spoon Sample Total Depth =21' - I [Bedrock not encountered - Unrecovered Sample Groundwater not encountered - Standard Penetration Test Sample 35 40 Note: The stratification lines represent the approximate - boundaries between the soil types; the transition may be _ gradual. 45 50 Sladden Engineering 176 -Lot Green Property SWC'Quarry Ranch Road & Jefferson Street Date: 12/1/2004 -Boring No. 5. Job Number: 544 -4769 q tj a pq Descri tion r° U a 3 c 0 C14 Remarks 0 Native Soil 5 9/24/30 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 7 Brown in color - with Rock Fragments 10 11/14/20 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 6 Brown in color - with Rock Fragments Refusal —14 Feet 15 - California Split -spoon Sample Total Depth =--14' - I edrock not encountered >< 20 _ Unrecovered Sample I Groundwater not encountered - Standard. Penetration Test Sample 25 - Note: The stratification lines represent the approximate - boundaries between the soil types; the transition may be _ gradual. 30 35 40 45 50 Sladden Engineering 176 -Lot Green'Property SWC Quarry Ranch - Road.& Jefferson Street Date: 12/1/2004 -Boring No. 6 Job Number: 5444769 a � 0 ell o a Description a o o Remarks rn U pq �° 0 Native Soil 5 6/10/17 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 7 Brown in color - with Rock Fragments - Refusal @ — 8 Feet 10 15 20 - California Split -spoon Sample Total Depth = 8' 25 Bedrock not encountered Unrecovered Sample Groundwater not encountered - Standard Penetration Test Sample 30 - Note: The stratification lines represent the approximate - boundaries between the soil types; the transition may be _ gradual.'. 35 40 45 50 Sladden Engineering 176= Lot'Green Property SWC Quarry Ranch Road.& Jefferson Street Date: 12/3/2004 :Boring No. 7 Job Number: 544 -4769 a 0 CI4 4~ � o. u 0 o 0 " g cn U M Description W o Remarks 0 Native Soil 5 11/11/17 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 8 10 19/30/37 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 9 - with Rock Fragments - Refusal @ —12 Feet 15 - California Split-spoon Sample Total Depth =12' Bedrock not encountered 20 _ Unrecovered Sample I Groundwater not encountered - Standard Penetration Test Sample 25 - Note: The stratification lines represent the approximate - boundaries between the soil types; the transition maybe _ gradual. 30 35 '40 45 50 Sladden Engineering t. 1"76 -Lot Green Property •SWC Quarry <Ranch Road. &.Jefferson'Street Date: 12/3/2004 -Boring No. 8 Job Number: 544 -4769 0 U 0 c � a 3 {' j 0 q � pq ° Remarks Description � o 0 Native Soil E 5 13/17/23 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 6 Brown in color - with Rock Fragments 10 €'s 15/20/29 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 5 Brown in color ` - with Rock Fragments r ...• - efusal @ —14 Feet t ' IS - California Split-spoon Sample Total Depth = 14' - edrock not encountered 20 Unrecovered Sample Groundwater not encountered k' = Standard Pen@hation Test Sample 25 - Note: The stratification lines represent the approximate i` boundaries between the soil types; the transition may be gradual. 30 _v - 35 40 1 _ E.1 45 E, 5 ' - 50 F ? _ k L' • Sladden Engineering 176= Lot-Green Property -SWC Quarry-Ranch •Road..& Jefferson Street Date: 12/3/2004 Boring No: 9 Job Number: 5444769 a 0 � o ° 3 U pq Description r° Remarks 0. Native Soil 5 17/25/33 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 7 Brown in color - with Rock Fragments 10 17/24/32 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 6 Brown in color - with Rock Fragments 15 28/28/35 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 5 Brown in color - with Rock Fragments - California Split -spoon Sample Total Depth =x15.5' - edrock not encountered . 20 - Unrecovered Sample I Groundwater not encountered - Standard Penetration Test Sample 25 - Note: The stratification lines represent the approximate - boundaries between the soil types; the transition may be _ gradual. 30 35 40 45 50 Sladden Engineering 176- Lot.Green :Property •SWC Quarry°Ranch Road & Jefferson Street Date: 12/3/2004 Moring No. 10 Job Number: 544 -4769 C Description 4. a 3 o CD 0 4k >~ Remarks 0 Native Soil 5 7/9/10 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 11 7 Brown in color - with Rock Fragments '10 12/15/17 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 2 10 Brown in color - with Rock Fragments 15 13/15/17 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 8 Brown in color - with Rock Fragments 20 ': 9110/15 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 5 Brown in color - with Rock Fragments 25 ': 1820/32 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 2 13 Brown in color - with Rock Fragments 30 ?. 172024 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 7 Brown in color - with Rock Fragments - California Split-spoon Sample otal'Depth = 30.5' 35 Groundwater not encountered - Unrecovered Sample I Bedrock not encountered - - Standard Penetration Test Sample 40 - Note: The stratification lines represent the approximate - boundaries between the soil types; the transition may be 45 gradual. 50 Sladden Engineering 176= Lot Green Property -SWC -Quarry Ranch - Road;& Jefferson-Street Date: 12/3/2004 Boring No. 11 Job Number: 544 -4769 0 3 a u o _. rn U Description rn0 o Remarks 0 alive Soil 5 5/47/28 Sand: Fine to Coarse Grained and 118" to 1/4" Gravel SP 1 7 Brown in color - with Rock Fragments 10 's €€ 13/17/19 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 0 6 Brown in color - with Rock Fragments 15 50-5" Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 10 Brown in color - with Rock Fragments 18 33/44/50 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 10 rown in color - with Rock Fragments 20 25 30 California Si lit -spoon Sample Total Depth =20' edrock not encountered - _ Unrecovered Sample I Groundwater not encountered - Standard Penetration Test Sample 35 40 Note: The stratification lines represent the approximate - boundaries between the soil types; the transition may be - gradual. 45 50 Sladden Engineering 176 -Lot Green •Property SWC Quarry:RanchRoad:& Jefferson-Street Date: 12/3/2004 Soring No. 12 Job Number: 5444769 U o 0 N a as c 3 o Description o Ln •� $ Remarks p Native Soil 5 16/23/37 Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 8 - with Rock Fragments 10 50 -5" Sand: Fine to Coarse Grained and 1/8" to 1/4" Gravel SP 1 9 - with Rock Fragments Refusal @ —11 Feet 15 20 - California Split -spoon Sample Total Depth 1.1' 25 Bedrock not encountered - - Unrecovered Sample I Groundwater not encountered - Standard Penetration Test Sample 30 - Note: The stratification lines represent the approximate - boundaries between the soil types; the transition may be _ gradual. 35 40 45 50 Sladden Engineering � I � I � I � I APPENDIX B Laboratory Testing Laboratory Test Results APPENDDC B LABORATORY TESTING Representative bulk and relatively undisturbed soil samples were obtained in the field and returned to our laboratory for additional observations and testing. Laboratory testing was generally performed in two phases. The first phase consisted of testing in order to determine the compaction of the existing natural soil and the general engineering classifications of the soils underlying the site. This testing was performed in order to estimate the engineering characteristics of the soil and to serve as a basis for selecting samples for the second phase of testing. The second phase consisted of soil mechanics testing. This testing including consolidation, shear strength and expansion testing was performed in order to provide a means of developing specific design recommendations based on the mechanical properties of the soil. CLASSIFICATION AND COMPACTION-TESTING r ' Unit Weight and Moisture Content Determinations: Each undisturbed sample was weighed and measured in order 11 to determine its unit weight. A small portion of each sample was then subjected to testing in order to determine its moisture content. This was used in order to determine the dry density of the soil in its natural condition. The results F of this testing are shown on the Boring Logs. Maximum Density- Optimum Moisture Determinations: Representative soil types were selected for maximum density determinations. This testing was performed in accordance with the ASTM Standard D1557 -91, Test Method ' A. The results of this testing are presented graphically in this appendix. The maximum densities are compared to the field densities of the soil in order to determine the existing relative compaction to the soil. This is shown on the Boring Log, and is useful in estimating the strength and compressibility of the soil. j, Classification Testing: Soil samples were selected for classification testing. This testing consists of mechanical grain.. size analyses and Atterberg Limits determinations. These provide information for developing classifications for the soil in accordance with the Unified Classification System. This classification system categorizes the soil into groups having similar engineering characteristics. The results of this testing are very useful in detecting variations in the soils and in selecting samples for further testing. SOIL MECHANIC'S TESTING Direct Shear Testing: One bulk sample was selected for Direct Shear Testing. This testing measures the shear strength. of the soil under various normal pressures and is used in developing parameters for foundation design and lateral design. Testing was performed using recompacied test specimens, which were saturated prior to testing. Testing was performed using a strain controlled test apparatus with normal pressures ranging from 800 to 2300 pounds per square foot. Expansion Testing. One bulk sample was selected for Expansion testing. Expansion testing was performed in accordance with the UBC Standard 18 -2. This testing consists of remolding 4 -inch diameter by 1 -inch thick test specimens to a moisture content and dry density corresponding to approximately 50 percent saturation. The samples are subjected to a surcharge of 144 pounds per square foot and allowed to reach equilibrium. At that point the specimens are inundated with distilled water. The linear expansion is then measured until complete. Consolidation Testing: Four relatively undisturbed samples were selected for consolidation testing. For this testing one -inch thick test specimens are subjected to vertical loads varying from 575 psf to 11520 psf applied progressively. The consolidation at each load increment was recorded prior to placement of each subsequent load. The specimens ' were saturated at the 575 psf or 720 psf load increment. Gradation ASTM C117 & C136 Project Number: 544 -4769 Project Name: S.W.C. 38th & Jefferson, La Quinta Sample ID: Bulk 8 @ 0 =5' Sieve Sieve Percent Size, in Size, mm Passing 1" 25.4 100.0 3/4" 19.1 100.0 1/2" 12.7 100.0 3/8" 9.53 100.0 #4 4.75 98.0 #8- 2.36 89.0 #16 1.18 66.0 #30 0.60 40.0 #50 0.30 20.0 #100 0.15 10.0 #200 0.07.4 6.0 December 22, 2004 IIIII� ■ ■rinlli�� ■ ■IIIII� ■■ ■11111 ■ ■ ■IIIII� ■ ■■ ., IIIII�■■■ IIIII�i . ■IIIII� ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ 11111■■■ IIIII� ■id■IIIII� ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ . , IIIII� ■ ■■ 11111 ■!►�IIIII� ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ IIIII� ■ ■ ■IIIII� ■ ■\ IIIII� ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ IIIII� ■ ■ ■IIIII� ■ ■ \�IIIII� ■■ ■11111 ■■ ■11111 ■ ■■ IIIII� ■ ■ ■IIIII�■ ■!'11111 ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ 11111 ■ ■■ 11111 ■ ■l�11111� ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ '' ' IIIII� ■ ■■ 11111 ■■ ■►1111 ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ , IIIII� ■ ■ ■IIIII� ■ ■ ■1►111� ■■ ■11111 ■ ■ ■IIIII� ■ ■■ IIIII� ■ ■■ 11111 ■■ ■11111 ■ ■ ■Illlli ■ ■ ■IIIII� ■ ■■ - , , 11111■■■ i11111�■ ■■III►���■ ■■IIIII�■ ■■IIIIe�■■i■ IIIII�■■■ 11111 ■■■111 ►��■■■11111�■■ ■11111■■ 11111■■■ 11111 ■■■11111■ ■■IIIII�■■■IIIIIe■■■, 11111■ ■■ 11111 ■■■11111��■■11111�■■■11111�■■■ 11111■■■ 11111■ ■■11111�►��■11111�■ ■■11111■■■ 11111N■■■11111�■ ■ ■IIIIie� �■11111�■■ ■11111■■■ 11111 ■ ■1■11111■■■11111�■�w;�A11�■ ■■11111■■■ 111111■■■ 11111 ■■■11111■ ■�....11�■■■11111�■■■ 11111■■■ 11111■■ ■11111■ ■■IIIII�■ ■■IIU1�■ ■■ f i l l . , , , „ Gradation Sladden Engineering Revised 11/20/02 =Gradation ASTM C117 & C136 Project Number: 544 -4769 Project Name: S.W.C. 38th & Jefferson, La Quinta Sample ID: Boring 8 @ 5' Sieve Sieve Percent Size, in Size, mm Passing - '1" 25.4 100.0 3/4" 19.1 100.0 1/2" 12.7 100.0 3/8" 9.53 100.0 #4 4.75 94.0 #8 2.36 78.0 #16 1.18 54.0 #30 0.60 32.0 #50 . 0.30 17.0 . #100 0.15 9.0 #200 0.074 6.0 December 22, 2004 IIIII� ■r�111i1� ■ ■ ■IIIII� ■ ■ ■IIIII� ■■ ■111111 ■ ■■ ., IIIII�■■■ IIIII� \ ■ ■IIIII� ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ IIIII� ■ ■ ■IIIII� \\ ■IIIII� ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ IIIII� ■ ■ ■IIIII� ■� ■IIIII� ■ ■ ■IIIII� ■■ ■11111 ■ ■■ 11111 ■ ■ ■IIIII� ■t7 ■IIIII� ■ ■ ■IIIII� ■■ ■11111 ■ ■■ IIIII� ■ ■ ■IIIII� ■�, 11111 ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ Iilll� ■■ ■11111 ■ ■► 11111 ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ IIIII� ■■ ■11111 ■ ■� IIIII� ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ = ' illll� ■ ■ ■IIIII� ■ ■��IIIII� ■ ■ ■IIIII� ■■ ■11111 ■ ■■ IIIII�■■■ IIIII� ■ ■`illlll� ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ IIIII� ■ ■ ■IIIII� ■ ■ ■�1111� ■■ ■11111 ■ ■ ■IIIII� ■ ■■ -- , , IIIII�■■■ IIIII� ■ ■ ■t►111� ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ IIIII� ■ ■ ■IIIII� ■■ ■11111 ■ ■ ■IIIII� ■ ■ ■IIIII� ■■ IIIII� ■ ■ ■IIIII� ■■ ■III!! ■■ ■11111 ■■ ■11111 ■ ■� 111110 ■ ■■ 11111 ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ tllll� ■ ■ ■IIIII� ■■ ■11111 \� ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ IIIII ■ ■ ■IIIII� ■ ■ ■IIIII�lS ■IIIII� ■■ ■11111 ■ ■■ IIIIIC. ■..11111..■ ■11111... - ..11111... ■IIIII� ■.�■ IIIII�■■■ IIIII� ■■ ■IIIII�■■r:!�1� ■■ ■IIIII� ■ ■■ 11111■■ ■IIIII�■ ■ ■IIIII� ■ ■ ■II 11� ■ ■ ■I1111� ■ ■■ fill MW off oil Gradation Sladden Engineering Revised 11/20/02 `Gradation ASTM C117 & C136 Project Number: 544 -4769 Project Name: S.W.C. 38th & Jefferson, La Quinta Sample ID: Boring 8 @ 10' Sieve Sieve Percent Size, in Size, mm Passing lit 25.4 100.0 3/4" 19.1 100.0 1/2" 12.7 100.0 3/8" 9.53 100.0 #4 4.75 92.0 #8 2.36 79.0 #16 1.18 56.0 #30 0.60 33.0 #50 0.30 17.0 #100 0.15 9.0 #200 0.074 5.0 December 22, 2004 IIIII�■ r��li�1� ■ ■ ■IIIII� ■ ■ ■IIIII� ■■■IIIIII■■■ ., IIIII� ■■ ■11111 ■ ■ ■IIIII� ■■ ■11111 ■ ■ ■IIIII� ■ ■■ 1111 ■ ■ ■IIIII� \■ ■11111 ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ ., IIIi�■■■ IIIII� ■, ■IIIII� ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ IIIII� ■ ■ ■IIIII� ■ii ■IIIII� ■■ ■11111 ■■ ■11111 ■ ■■ IIIII�■■■ IIIII� ■ ■�11111� ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ IIIII�■■■ IIIII� ■ ■ \�IIIII� ■ ■ ■IIIIi� ■ ■ ■IIIII� ■ ■■ 11111 ■ ■ ■IIIII� ■ ■ \�IIIII� ■■ ■11111 ■ ■ ■IIIII� ■ ■■ '' ' � 11111■■■ IIIII� ■ ■!'lllll� ■ ■ ■IIIII� ■ ■ ■IIIII� ■ ■■ . , IIIII� ■■ ■IIIII�■■ ■IIIII�■ ■ ■IIIII�■ ■■11111■■■ IIIII�■■■ Ilill� ■■ ■►�IIi�■ ■■Iilll�■ ■■IIIII�■■■ �- , IIIIIC■■■ 11111 ■ ■■1►1I1�■ ■ ■IIIIIt■■■Illlle■■■ VIII ■e■ 111111 ■■■11��1� ■ ■■11111�■■■11111�■■■ IIII1�■■ ■IIIII�■■ ■IIIL'��■■■IIIIi�■■■II I1� ■■■ IIII1�■■■ IIIIi� ■■■III1�!■■■IIIIe�■■■11�11�■■■ 11111�■■■11111�■■ IIIII�� ■■IIIII�■■■11111�■ ■■ 11111�■■i■ 11111 !■ ■�IIII1�lS■IIII1�■ ■■IIII1� ■■■ �III1�■■■ VIII,■ ■ ■IIII1�■ \`.�IIII1�■■■11111i■ ■■ II11�■■■ IIII1� ■■■11111�■■ru�ll�■■■illll�■■■ 11111■■■ 11111 ■■■11111■ ■■11�11�■■■11I11�■ ■■ Will logo Gradation Sudden Engineering Revised 11/20/02 Maximum :=Density /Optimum Moisture ASTM D698/D1557 Project Number: 544 -4769 ProjectName: S.W.C. 38th & Jefferson, La Quinta Lab ID Number: Sample Location: Bulk.8 @ 0 -5' Description: Sand with Gravel Maximum Density: 122 pef Optimum Moisture: 9.5% 145 140 135 130 v a' 125 H ii 07 A 120 L. Q 115 110 105 1004 0 Sieve Size % Retained 3/4" 3/8" #4 0.0 December 22, 2004 ASTM D -1557 A Rammer Type: Manual _ 1 M_____ 5 10 15 Moisture Content, % 20 25 Max Density Sladden Engineering Revised 12/03/02 Expansion Index ASTM D 4829/UBC 29 -2 Job Number: 544 -4769 Date: 12/22/2004 Job Name: S.W.C. 38th & Jefferson, La Quin Tech: Jake Lab. ID: Sample ID: Bulk 8 @ 0 -5' Soil Description; Sand with Gravel Wt of Soil + Ring: 595.0 Weight of Ring: 179.0 Wt of Wet Soil: 416.0 Percent Moisture: 1 8% Wet Density, cf 126.0 Dry Densti, cf: 116.7 Saturation: 48.7 Expansion Rack # Date /Time 12/24/2004 10:30 AM Initial Reading 0.500 Final Reading 0.500 Expansion Index (Final - Initial) x 1000 0 0 E1 Sladden Engineering Revised 12/10/02 . I j El r, tj APPENDIX C 1997 LJBC Seismic Design Criteria 1 January 26, 2005 -16- Project No. 544 -4769 ' 05 -01 -075 ' 1997.UNIFORM BUILDING CODE SEISMIC DESIGN INFORMATION The International Conference of Building Officials 1997 Uniform Building Code contains substantial revisions and additions to the earthquake engineering section in Chapter 16. Concepts contained in the code that will be relevant to construction of the proposed structures are summarized below. Ground shaking is expected to be the primary hazard most likely to affect the site, based upon proximity to significant faults capable of generating large earthquakes. Major fault zones considered to be most likely to create strong ground shaking at the site are listed below. Fault.Zone Approximate Distance From Site Fault Type (1997 UBC) San Andreas 14.8 km A San Jacinto 26.7 km A Based on our field observations and understanding of local geologic conditions, the soil profile type judged applicable to this site is SD, generally described as stiff or dense soil. The site is located within UBC Seismic Zone 4. The following table presents additional coefficients and factors relevant to seismic mitigation for new construction upon adoption of the 1997 code. Sladden Engineering Near- Source Near- Source Seismic Seismic Seismic Acceleration Velocity Coefficient Coefficient Source Factor, Na Factor, Ny Ca C� San Andreas 1.0 1.0 0.44Na 0.64N� San Jacinto . 1.0 1.0 0.44Na 0.64N,, Sladden Engineering JOB NUMBER: 544 -4769 * * * * * * * * * * * * * * * * * * * * * ** * * * E Q F A U L T * * * Version 3.00 * * * * * * * * * * * * * * * * * * * * * * * ** DETERMINISTIC ESTIMATION OF PEAK ACCELERATION FROM DIGITIZED FAULTS DATE: 02 -01 -2005 JOB NAME: SWC Quarry Ranch Road & Jefferson Street La Quinta, California CALCULATION NAME: Test Run Analysis FAULT - DATA -FILE NAME: CDMGFLTE.DAT SITE COORDINATES: SITE LATITUDE: 33.6231 SITE LONGITUDE: 116.2722 SEARCH RADIUS: 100 mi ATTENUATION RELATION: 5) Boore et al. (1997) Horiz. - SOIL (310) UNCERTAINTY (M= Median, S= Sigma): M Number of Sigmas: 0.0 DISTANCE MEASURE: cd_2drp SCOND: 0 Basement Depth: 5.00 km Campbell SSR: Campbell SHR: COMPUTE PEAK HORIZONTAL ACCELERATION FAULT -DATA FILE USED: CDMGFLTE.DAT MINIMUM DEPTH VALUE (km): 0.0 --------- - - - - -- EQFAULT SUMMARY --------- - - - - -- ----------------------------- DETERMINISTIC SITE PARAMETERS ----------------------- - - - - -- Page 1 ------------------------------------------------------------------------------- I IESTIMATED MAX. EARTHQUAKE EVENT I APPROXIMATE I------------------------------- ABBREVIATED I DISTANCE I MAXIMUM I PEAK JEST. SITE FAULT NAME I mi (km). IEARTHQUAKEI SITE (INTENSITY I I MAG.(Mw) I ACCEL. g 1MOD.MERC. SAN ANDREAS - Coachella 1 9.2( 14.8)1 7.1 1 0.266 1 IX SAN ANDREAS - Southern I 9.2( 14.8)1 7.4 1 0.312 1 IX SAN JACINTO -ANZA 1 16.6( 26.7)1 7.2 1 0.184 1 VIII SAN JACINTO- COYOTE CREEK 1 17.7( 28.5)1 6.8 1 0.142 1 .VIII BURNT MTN. 1 23.1( 37.1)1 6.4 1 0.094 1 VII SAN ANDREAS - San Bernardino 1 23.9( 38.4)1 7.3 1 0.147. 1 VIII EUREKA PEAK 1 24.0( 38.7)1 6.4 1 0.091 1 VII SAN JACINTO - BORREGO 1 29.6( 47.6)1 6.6 1 0.086 1 VII EARTHQUAKE VALLEY 1 35.3( 56.8)1 6.5. 1 0.072. 1 VI PINTO MOUNTAIN 1 35.5( 57.2)1 7.0 1 0.093 1 VII EMERSON So. - COPPER MTN. 1 37.3( 60.0)1 6.9 1 0.085 1 VII BRAWLEY SEISMIC ZONE 1 37,.7( 60.7)1 6.4 1 0.064 I VI SAN JACINTO -SAN JACINTO VALLEY 1 38:0( 61.1)1 6.9 1 0.083 .1 VII LANDERS 1 38.2( 61.5)1 7.3 1 0.103 1 VII PISGAH - BULLION MTN.- MESQUITE•LK 1 38.7( 62.3)1 7.1. 1 0.091 1 VII ELSINORE- JULIAN 1 39.3( 63.3)1 7.1 1 0.090 1 VII NORTH FRONTAL FAULT ZONE (East) 1' 42.9( 69.0)1 6.7 1 0.083 1 VII ELMORE RANCH 1 44.6( 71.8)1 6.6 1 0.063 1 VI ELSINORE- COYOTE MOUNTAIN 1 45.7( 73.6)1 6.8 1 0.069 I VI ELSINORE - TEMECULA 1 45.9( 73.8)1 6.8 1 0.068 1 VI SUPERSTITION MTN. (San Jacinto) 1 48.0( 77.2)1 6.6 1 0.059 1 VI JOHNSON VALLEY (Northern) 1 49.0( 78.9)1 6.7 1 0.062 1 VI SUPERSTITION HILLS (San Jacinto)1 49.0( 78.9)1 6.6 1 0.058 1 VI CALICO - HIDALGO 1 50.8( 81.7)1 7.1 1 0.074 1 VII ' NORTH FRONTAL FAULT ZONE (West) 1 54.4( 87.•5)1 7.0 1 0.081 1 VII LENWOOD - LOCKHART -OLD WOMAN SPRGSJ 54.6( 87.9)1 7.3 1 0.078 1 VII SAN JACINTO -SAN BERNARDINO 1 61.8( 99.5 )1 6.7 1 .0.052 I VI ELSINORE -GLEN IVY 1 61.9( 99.6 )1 6.8 1 0.054 1 VI HELENDALE - S. LOCKHARDT I 62.1( 99.9 )1 7.1 1 0.063 1 VI IMPERIAL 1 63.6( 102.4)1 7.0 1 0.059 1 VI LAGUNA SALADA 1 66.0( 106.2)1 7.0 1 0.057 1 VI CLEGHORN 1 70.4( 113.3)1 6.5 1 0.042 1 VI ROSE CANYON 1 73.6( 118.4)1 6.9 1 0.050 1 VI NEWPORT- INGLEWOOD (Offshore) 1 74.0( 119.1)1 6.9 1 0.050 1 'VI CHINO- CENTRAL AVE. (Elsinore) 1 75.9( 122.1)1 6.7 1 0.053 1 VI CUCAMONGA 1 77.3( 124.4)1 7.0 1 0.062 1 VI WHITTIER 1 80.2( 129.0)1 6.8 1 0.044 1 VI SAN ANDREAS - Mojave 1 86.6( 139.3)1 7.1 I 0.049 1 VI SAN ANDREAS - 1857 Rupture 1 86.6( 139.3)1 7.8 1 0.071 1 VI SAN JOSE 1 88.4( 142.2)1 6:5 1 0.043 1 VI ----------------------------- DETERMINISTIC SITE PARAMETERS ----------------------- - - - - -- Page 2 -------------------------------------=----------------------------------------- I (ESTIMATED MAX. EARTHQUAKE EVENT IAPPROXIMATE 1---------------=--------------- ABBREVIATED I DISTANCE I MAXIMUM I PEAK JEST. SITE FAULT NAME 1 mi ()an) IEARTHQUAKEI SITE JINTENSITY I I MAG.(Mw) I ACCEL. g JMOD.MERC. CORONADO BANK 1 88.4( 142.2)1 7.4 1 0.056 J VI SIERRA MADRE 1 91.2( 146.8)1 7.0 1 0.054 1 VI ELYSIAN PARK THRUST 1 92.7( 149.2)1. 6.7 1 0.046 1 VI GRAVEL HILLS - HARPER LAKE 1 94.0( 151.3)1 6.9 1 0.041 1 V NEWPORT- INGLEWOOD (L.A.Basin) 1 95.1( 153.0)1 6.9 1 0.041 1 V COMPTON THRUST 1 98.6( 158.7)1 6.8 1 0.046 I VI PALOS VERDES 1 98.7( 158.9)1 7.1 .1 0.044 1 VI -END OF SEARCH- 47 FAULTS FOUND WITHIN THE SPECIFIED SEARCH RADIUS. THE SAN ANDREAS - Coachella FAULT IS CLOSEST TO THE SITE. IT IS ABOUT 9.2 MILES (14.8 km) AWAY. LARGEST MAXIMUM- EARTHQUAKE SITE ACCELERATION: 0.3120 g 110C '1000 900 800 700 m 500 400 300 200 100 0 -100 -wuu -juu -200 -100 CALIFORNIA =FAULT MAP SWC Quarry Ranch Road & Jefferson Street 0 100 200 300 400 500 600 k 1 II MAXIMUM EARTHQUAKES -SWC Quarry Ranch Road & Jefferson Street 1 .1 .-Ol .001 10 100 Distance (mi) I f 0 Cu 6,' 0 II MAXIMUM EARTHQUAKES -SWC Quarry Ranch Road & Jefferson Street 1 .1 .-Ol .001 10 100 Distance (mi) EARTHQUAKE MAGNITUDES .& 'DISTANCES S'WC,Quarry Ranch Road..& Jefferson -Street 7.7-5 7.50 7.25 7.00 rn Cu 6.75 Illowt 10 100 Distance (mi) TN /City of La Quinta TTM 33444 EA/8.24.05 Technical Reports Slope Analysis Geotechnical Investigation Proposed 176 Lot residential Subdivision Green Property La Quinta, California Prepared by Sladden Engineering 39 -725 Garand Lane, Suite G Palm Desert, CA 92211 January 26, 2005 � � Sladden Engineering II 6782 Stanton Ave., Suite A, Buena Park, CA 90621 (714) 523-0952 Fax (714) 523 -1369 39 -725 Garand Ln., Suite G, Palm Desert, CA 92211 (760) 772 -3893 Fax (760) 772 -3895 May 18, 2005 DDC Desert Development, Inc. 74 -001 Reserve Drive Indian Wells, California 92210 Attention: Mr. Tom Cullinan Project: Proposed 176 Lot Residential Subdivision — Green Property SWC Quarry Ranch Road and Jefferson Street ' La Quinta, California Project No. 544 -4769 05 -05 -507 Ref: Geotechnical Investigation report prepared by Sladden Engineering dated January ' 26, 2005; Project No. 544 -4769, Report No. 05 -01 -075 ' As requested, we have reviewed the above referenced geotechnical report and revisited the site to further evaluate the slope stability of the natural hillsides and proposed graded slopes within or -- ..::.- adjacent fbihe above reference project. ' The project site is located along the base of the Santa Rosa Mountains and steep slopes of exposed bedrock form the western and eastern property boundaries. The natural slopes consist of. . ' weathered bedrock with scattered loose boulders and cobbles throughout the exposed surface. Some of the surface boulders and cobbles may be susceptible to downslope movement resulting from erosion or seismic events. The proposed site configuration including the construction of ' drainage swales along the base of the natural hillside should adequately mitigate rockfall or rolling boulder hazards. ' In addition, supplemental slope stability analyses were performed in order to confirm the stability of the proposed cut and fill slopes..Our analyses suggest that the proposed engineered slopes to be constructed at a 2 to 1 (horizontal to vertical) slope angle should be stable. ' The strength criteria utilized in our slope stability analyses were determined from the results of direct shear testing included within the geotechnical report. The stability analyses were I performed .using a personal computer and the PCSTABLSM software package. Some sample slope stability calculations are attached. May 18, 2005 -2- Project No. 544 -4769 05 -05 -507 ' If you have any questions regarding this memo or the referenced report, please contact the undersigned. ' Respectfully submitted, SLADDEN ENGINEERING '' �. Sladden Engineering Qp p SSlCA 1 NANO �0 0 CO Brett L. Anderson Exp. 9130106 M Principal Engineer ' Letter /pc 0 F CA��FO�� ' Copies: 4/DDC Desert Development, Inc. Sladden Engineering '" ** PCSTABL5M ** ' by Purdue University -------------------------------------------------------------------------------- ' - -Slope Stability Analysis-- Simplified Janbu, Simplified Bishop ' or Spencer's Method of Slices Run Date: 05 -18 -05 ' Time of Run: 3:59pm Run By: Hogan R. Wright Input Data Filename: F:5444769A ' Output Filename: F:5444769A.OUT Plotted Output Filename: F:5444769A.PLT PROBLEM DESCRIPTION SWC Quarry Ranch Rd & Jefferson 544 -4769 ' Slope: 2 to 1, 40' high BOUNDARY COORDINATES 3 Top Boundaries 3 Total Boundaries ' ISOTROPIC SOIL PARAMETERS 1 Type (s) of Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. ' Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) (deg) Param. (psf) No. 1 125.0 125.0 50.0 33.0 ..00 .0 1 '-------------------------=--------------------------------=------=------- - - - - -- I A Critical Failure Surface Searching Method, Using A Random Technique For Generating Circular Surfaces, Has Been..Specified. Boundary X -Left Y -Left X- Right. Y- Right Soil Type No. (ft) . (ft) (ft) (ft) . Below Bnd ' 1 30.00 30.00 60.00 30.00 1 2 60.00 30.00 140.00 70.00 1 3 140.00 70.00 200.00 70.00 .1 ------------------7---------------7--------------------------------7---------- ' ISOTROPIC SOIL PARAMETERS 1 Type (s) of Soil Soil Total Saturated Cohesion Friction Pore Pressure Piez. ' Type Unit Wt. Unit Wt. Intercept Angle Pressure Constant Surface No. (pcf) (pcf) (psf) (deg) Param. (psf) No. 1 125.0 125.0 50.0 33.0 ..00 .0 1 '-------------------------=--------------------------------=------=------- - - - - -- I A Critical Failure Surface Searching Method, Using A Random Technique For Generating Circular Surfaces, Has Been..Specified. ' 160 Trial Surfaces Have Been Generated. ' 20 Surfaces Initiate From Each Of 8 Points Equally Spaced Along The Ground Surface Between X = 31.00 ft. and X = 60.00 ft. Each Surface Terminates Between X = 140.00 ft. ' and X = 199.00 ft. ' Unless Further Limitations Were Imposed, At Which A Surface Extends Is Y = The ft. Minimum Elevation .00 ' 3.00 ft. Line Segments Define Each Trial Failure Surface. -- - - - - - - - - - - - - - - -- - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - - - - -- Following Are Displayed The Ten Most Critical Of The Trial Failure Surfaces Examined. They Are Ordered - Most Critical ' First. ' * * Safety Factors Are Calculated By The Modified Janbu.Method Failure Surface Specified By 36 Coordinate Points ' Point X -Surf Y -Surf No. (ft) (ft) 1 55.86 30.00 ' 2 58.81 29.44 3 61.77 29.00 ' 4 5 64.15 28.66' 67.75 28.44 6 70.74 28.33 7 73.74 28.33 ' 8 76.74 28.45 9 79.73 28.68 10 82.71 29.02 ' 11 12 85.68 29.47 88:63 30.03 13 91.55 30.71 14 94.44 31.49 ' 15 97.31 32.38 16 100.14 33.38 17 102.93 34.48 18 105.67 35.69 ' 19 108.37 37.00 20 111.02 38.41 21 113.61 39.92 22 116.15 41.52 23 118.62 43.22 24 121.03 45.01 25 123.37 46.89 26 125.63 48.86 27 127.82 50.91 28 129.94 53.04 29 131.97 55.25 30 133.91 .57.53 31 135.77 59.88 32 137.54 62.31 33 139.22 64.80 34 140.80 67.34 35 142.28 69.95 36 142.31 70.00 * ** 1.545 * ** Individual data on the 37 slices Water Water Tie Tie Earthquake Force Force Force Force Force Surcharge Width Weight Top Bot Norm Tan Hor Ver Load Ft (m) Lbs (kg) Lbs (kg) Lbs (kg) Lbs (kg) Lbs (kg) Lbs (kg) Lbs (kg) Lbs (kg) 2.:.9.....:..1.02 �...:; .:_..:.- a_..:..... . o 0 0 0 0 0 1.2 96.6 .0 .0 .0 .0 .0 .0 .0 1.8 290.9 0 .0 .0 .0 .0 .0 0' .3.0 1044.1 .0 .0 .0 .0 .0 0 .0 3.0 1710.3 .0 .0 .0 .0 .0 .0 .0 3.0 2337.2 .0 .0 .0 .0 .0 .0 .0 3.0 2921.1 .0 .0 .0 0 .0 .0 .0 3.0 3458.5 .0 .0 .0. .0 .0 .0 .0 3.0 3946.6 .0 .0 .0 .0 .0 .0 .0 3.0 4382.9 .0 .0 .0 :0 .0 .0 .0 .3.0 4765.2 .0 .0 .0 .0 .0 .0 0 2.9 5092.1 .0 .0 .0. .0 .0 .0 .0 2..9 5362.3 ..0 .0 .0, .0 .0 .0 .0 2.9 5575.2 .0 .0 .0 .0 .0 .0 .0 2.9 5730.8 .0 .0 .0 .0 .0 .0 A 2.8 5829.2 .0 .0 .0 .0 .0 .0 .0 2.8 5871.4 .0 .0 .0 .0 .0 .0 .0 2.7 5858.5 .0 .0 .0 .0 .0 .0 .0 2.7 5792.3 .0 .0 .0 .0 .0 .0 .0 2.6 5675.0 .0 .0 .0 .0 .0 .0 .0 2.6 5509.2 .0 .0 .0 .0 .0 .0 .0 2.5 5297.8 .0 .0 .0 .0 .0 .0 .0 2.5 5044.5 .0 .0 .0 .0 .0 .0 .0 2.4 4752.8 0 .0 .0 .0 .0 .0 .0 2.3 4427.0 .0 .0 .0 .0 .0 .0 A 2.3 4071.6 .0 .0 .0 .0 .0 .0 .0 2.2 3691.2 .0 .0 .0 .0 0 .0 .0 2.1 3291.0 .0 .0 .0 .0 .0 .0 .0 29 2.0 2876.2 .0 .0 .0 .0 .0 .0 .0 '30 1.9 2452.1 .0 .0 .0 .0 .0 .0 .0 31 1.9 2024.6 .0 .0 .0 .0 .0 .0 .0 32 1.8 1599.1 .0 .0 .0 .0 .0 .0 .0 1.7 1181.7 .0 .0 .0 .0 .0 .0 .0 '33 34 .8 428.9 .0 .0 .0 .0 .0 .0 .0 35 .8 329.3 .0 .0 .0 .0 .0 .0 .0 36 37 1.5 .0 251.2 .1 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 .0 0 .0 Failure Surface Specified By 38 Coordinate Points Point X -Surf Y -Surf ' No. (ft) (ft) 1 43.43 30.00 2 46.41 29.65 ' 3 49.40 29.39 4 52.39 29.21 5 55.39' 29'.12 6 58.39 29.11 7 61.39 29.18 8 64.39 29.34 ' 9 10 67.38 70.36 29.59 29.92 11 73.33 30.33 12 76.29 30.83 ' 13 79.23 31.41 -14 82.16 32.07 1.5....:......_._...... 85.06 32.81 16 87.95 33.64 ' 17 90.81 34.55 18 93.64 35.54 19 96:44. 36.61 ' 20 99.21. 37.75 21 101.95 38.98 22 104.66 40.28 23 107.32 41:66 24 109.95 43.11 25 112.53 44.63 26 27 115.07 117.56 46.23 47.90 28 120.01 49.64 29 122.40 51.45 30 124.74 53.32 31 127.03 55.26 32 129.27 57.26 33 131.44 59.33 ' 34 133.56 61.45 35 135.62 63.64 36 137.61 ' 37 139.54 ,65.88 68.18 38 140.98 .70.00 * ** 1.547 * ** t------------------------------------------------------------------------------ ' Failure Surface Specified By 40 Coordinate Points I'll' Point X -Surf Y -Surf No. (ft) (ft) 1 47.57 30.00 2 50.56 29.72 ' 3 53.55 29.51 4 56.55 29.38 5 59.55 29.32 6 62.55 29.33 7 65.55 29.42 8 68.54 29.58 ' 9 71.53 29.82 10 74.52 30.13 11 77.49 30.51 12 80.46 30.96 13 83.41 31.4'9 14 86.35 32.09 ' 15 16. 89:27 92.18 32.76 33.51 17 95.07 34.32 18 97.93 35.21 19 100.78 36.17 20 103.60 37.19 21 106.3`9 38.29 ' 22 23 109.15 111.89 39.45 40.69 24 114.59 41.98 25 117.26 43.35 ' 26 119.90 44.78 27 122.50 46.27 28 125.07 47.83 29 127.59 49.45 ' 30 130.07 51.14 31. 132.52 52.88 32 33 134.91 137.27 54.68 56.54 34 139.57 58.46 35 141.83 60.44 ' 36 144.04 62.46 37 146.20 64.55 38 148.31 66.68 39 150.36 68.87 ' 40 151:37 70.00 ' * ** 1.585 * ** 1 Failure Surface Specified By 41 Coordinate Points ' Point X -Surf No. (ft) 1 43'.43 2 46.37 .3 49.33 ' 4 52.30 5 55.28 6 58.27 7 61.26 ' 8 64.26 9 .67.26 ' 10 11 70.26 73.25 12 76.24 13 79.22 14 82.19 ' 15 85.14 16 88.07 17 90.99 .18 93.88 19 96.75 20. 99.60 21 .102.41 22 105.19 23 107.94 24 110.66 ' 25' 113.33 _.._ ° :. .....:......:x._...2.6....:._ ... __.... 115.9.6 . . ' 27 28 118.55 121.10 29 123.60 30 126.05 31 128.44 32 130.79 33 133.08 34 135.31. ' 35 137.48 36' 139.59 37 141.63 ' 38 143.62 39 145.53 40 147.38 ' 41 148.57 Y -Surf (ft) 30.00 29.40 28.89 28.47 28.13 27.88 27.72 27.64 27.66 27.76 27.94 28.22 28.58 29.03 29.56 3.0.18 30.88 31.67 32.55 33.50 34.54 35.66 36.86 38.14 39.50 40.94 42.45 44.04 45.70 47.4 .3 49.24 51.11 53.05 55.06 57.13 59.26 61.45 63.71 66..02 68.38 70.00 1:594 * ** r_________________________ __ _________ __ ___ ___ ______ _ _ _ _ __ Failure Surface Specified By 41 Coordinate Points Point X -Surf Y -Surf ' * ** 1.600 * ** I ' ' Failure Surface Specified By 40 Coordinate Points Point X -Surf No. (ft) (f t) ' ' 1 47.57 30.00 2 1 43.43 30.00 2 46.36 29.34 3 49.30 28.77 ' 4 52.26 28.29 5 55.24 27.90 6 58.22 27.60 ' 7 61.21 27.39 8 64.21 27.27 9 67.21 27.24 10 70.21 27.30 ' 11 73.21 27.45 12 76.20 27.70 ' 13 14 79.18 82.15 28.03 28.45 15 85.11 28.96 16 88.05 29.56 ' 17 90.97 30.25 18 93.86 31.02 19 96.74 31.89 20 99.58 32.84 ' 21 102.40 33.87 22'. 105.18 34.99 23 107.93 36.19 ' 24 110.64 37.48 25 113.31 38.84 26 115.94 40.29 27 118.52 41.81 ' 28 121..06 43.42 _............ 2- 9 .... ...... .........1-2-3--.--55-- 45.09. ' 30 31 125.98 128.36 46.85 48.67 32 130.69 50.57 33 132.96. 52:53 ' 34 135.16 54.56 35 .137.31 56.66 36 139.39 58.82 37 141.40 61.05 ' 38 143:35 63:33 39 145..22 65.67 40 41 147.03 148.40 68.07 70.00 ' * ** 1.600 * ** I ' ' Failure Surface Specified By 40 Coordinate Points Point X -Surf Y -Surf No. (f t) (ft) ' 1 47.57 30.00 2 50.44 29.12 1 3 53.34 28.35 4 56.26 27.68 ' 5 59.21 27.12 6 62.18 26.67 ' 7 8 65.16 68.15 26.33 26.10 9 71.15 25.98 10 74.15 25.97 ' 11 77.15 26.07 12 80.14 26.28 13 83.12 26.59 14 86.09 27.02 ' 15 89.04 27.56 16 91.97 28.20 17 94.88 28.95 ' 18 97.75 29.81 19. 100.59 30:77 20 103.40. 31.84 21 106.16 33.01 ' 22 108.88 34 -28 23 111.55 35.64 ' 24 25 .114.17 116.73 37.11 .38.67 26 119.23. 40.32 27 121.68 42.06 ' 28 124.05 43.89 29 126.36 45.81 30 128.59 47.81 31 130.75 49.89 ' 32 132.84 52.05 33 134.84 54.29 ' 34 35 136.76 138,59 56.59 58.97 36 140.33 61.41 37 141.99 63.91 38 143.55 66.48 ' 39 145.01 69.09 40 145.48 70.00 1.604 -- - - - - - - - Failure - - - - - - - - - - - - - - - - - - Surface Specified - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ----------- By 40 Coordinate Points ' Point X -Surf Y -Surf No. (ft). (ft) ' 1 51.71 30.00 2 54.63 29.29 3 57.57 28.68 4 60.52 28.17 5 63.50 27.76 6 66.48 27.45 i t 7 69.47 27.23 8 72.47 27.12 9 75.47 27.10 10 78.47 27.19 11 81.46 27.37 12 84.45 27.65 13 87.42 28.04 14 90.39 28.52 15 93.33 29.10 16 96.25 29.77 17 99.15 30.55 18 102.02 31.42 19 104.86 32.38 20 107.67 33.44 21 110.44 34.59 22 113.17 35.83 23 115.86 37.16 24 118.50 38.58 25 121.09 40.09 26 123.64 41.69 27 126.12 43.36 28. 128.55 45.12 .29 130.92 46.96 .30 133.23 48.88 31 135.48 50.87 32 137.65 52.93 33 139.76 55.07 34 141.79 57.27 35 143.75 59.55 36 145.63 61.88 6.4 . 2 8 38 149.16 66.73 39 150.80 69.25 40 151.26 70.00 * ** 1.622 * ** Failure Surface Specified By 39 Coordinate Points Point X -Surf Y -Surf No. (ft) (ft) 1 51.71 30.00 .2 54.54 28.98 3 57.40. 28.08 4 60.29 27.29 5 63.22 26.62 6 66.17 26.08 7 69.14 25.65 8 72.12 25.34. 9 75.11 25.16 10 78.11 25.10 11 81.11 25.16 12 84.11 25.34 ' 13 87.09 25.64 14 90.06 26.07 15 93.01 26.61 ' 16 17 95.94 98.83 27.28 28.06 18 101.70 28.96 19 104.52 29.97 20 107.30 31.11 21 110.03 32.35 22 112.71 33.70 23 115.33 35.16 ' 24 117.89 36.73 25 120.38 38.39 ' 26 27 122.80 12.5.15 40.16 42.03 28 127.42 43.99 29 129.61 46.04 30 131.72 48.18 31 133.73 50.40 32 135.66 52.70 33 34 137.48 139.21 55.08 57.53. 35 .140.84 60.05 36. 142.37 62.63 ' 37 143.79 65.28 38 145.10 67.98 39 145.98 70.00 1.•:.63.1..... ' Failure --------------------------.------------------------ Surface Specified By 42 Coordinate Points ' Point X -Surf Y -Surf No. (ft) (ft) ' 1 43.43 30.00 2 46.28 29.06 3 49.15 28.21 4 52.06 27.47 ' 5 54.99 26.82 6 '57.94 26.28 ' 7 8 60.91 63..89 25.85 25.51 9 66.88 25.29 10 69.88 25.16 11 .72.88 25.14 ' 12 75.88 25.23 13 78.87 25.42 14 15 81.86 84.83 25.71 26..11 16 87.79 26.61 Failure Surface Specified By 44 Coordinate Points Point X -Surf Y -Surf 17 90.73 27.21 1 18 93.64 27.92 2 33.94 19 96.53 28.73 36.90 20 99.39 29.63 4 39.87 21 102.22 30.64 5 ' 22 105.01 31.75 45.83 23 107.76 32.95 7 24 110.46 34.24 ' ' 25 113.12 35.63 9 54.82 26 115.73 37.12 57.82 60.82 27 118.29 38.69 63.82 27.72 28 120.78 40.35 27.96 ' 29 123.22 42.09 28.29 30 125.60 43.92 ' 31 32 127.91 .130.16 45.84 47.83 75.73 33 132.33 49.89 17 34. 134.43 52.04 18 35 136'' 45 54.25 19 36 138.40 56.54 37 140.26 58.89 ' 38 39 142.04 143..74 61.30 63.78 40 145.35 66.31 41 146.87 68.90 ' 42 147.46 70.00 ' * ** 1.638 * ** Failure Surface Specified By 44 Coordinate Points Point X -Surf Y -Surf No'. (ft) (ft) 1 31.00 30.00 2 33.94 29.42 3 36.90 28.91 .' 4 39.87 28.47 5 42.85 28.12 6 45.83 27.83 7 48.83 27.62 ' 8 51.82 27.49 9 54.82 27.43 ' 10 11 57.82 60.82 27.45 27.55 12 63.82 27.72 13 66.81 27.96 14 69.79 28.29 ' 15 72.76 28.68 16 75.73 29.i5 17 78.68 29.70 ' 18 81.61 30.32 19 84.53 31.01 20 87.43 31.78 21 90.31 32.62 22 93.17 33.54 23 96.00 34.52 24 98.81 35.58 25 .101.59 36.70 26 104.34 37.90 27 10.7.06 39.16 28 109.75 40.50 29 112.40 41.90 30 115.02 43.37 31 117.60 44.90 32 120.13 46.50 33 122.63 48.16 34 125.09 49.88 35 127.50 51.61 36 129.86 53.51 37 132.18 55.42 38 134.45 57.38 39, 136.67 59.40 40 138.84 61.48 41: 140.95 63.60 42 143.01 65.79 43 145.01 68.02 44 146.70 70.00 * ** 1.639 ** 0 SWC Quarry Ranch Rd & Jefferson 544- 4769'Slo&e: 2 to 1, 40' hig3h Ten Most Critical. F:5444769A.PLT :;By: Hogan R. Wright 05 -18 -05 :59pM 160 120 Y -Axis (f t) 80 40 A PCSTABL5M FSmin =1.55 X -Axis (ft) SWC Quarry Ranch Rd a Jefferson 544 -4769 Slope: 2 to 1 48' high All. surfaces .evaluated. F:5444769A.PLT 1 By: Hogan R. Wright 05 -1$ -85 3:59pM 68 128 Y -Axi 2 (f t? 80 48 a X =Axis Oft) tan 168 288 m ' TN /City of La Quinta TTM 33444 EA/8.24.05 ' Technical Reports Coral Canyon TTM #33444 Environmental Assessment Hydrology Prepared by PACE Pacific Advanced Civil Engineering 17520 Newhope Street, Suite 200 Fountain Valley, CA 92708 August 2, 2005 CORAL CANYON TTM #33444 ENVIRONMENTAL ASSESSMENT HYDROLOGY GREEN PROPERTY LA QUINTA, CALIFORNIA i Prepared for Terra Nova Planning & Research, Inc. 400 South Farrell Drive Suite B -205 Palm Springs, CA 92262 Prepared by PACE Pacific Advanced Civil Engineering 17520 Newhope Street, Suite 200 Fountain Valley, CA 92708 August 2, 2005 , I' Coral Canyon TTM # 33444 Environmental Assessment Hydrology August 2, 2005 Green Property— La Quinta 8041E Page 1 of 6 1. Introduction For the purposes of hydrologic analysis, the watershed of the proposed Coral Canyon project site (337 acres) is bordered by natural ridgelines to the east and west and a man -made Bureau of Reclamation (BOR) training dike (Devil Canyon Dike) to the south. The existing Quarry and Quarry Ranch developments are located immediately north of the proposed Coral Canyon project site. The interior margins of the watershed have steep craggy rocky terrain. The interior of the watershed is shallower with several natural dry streams which drain storm runoff to the northeast. Additionally, all of the runoff from the existing Quarry Project, the proposed Coral Canyon project and the undeveloped mountain side (total drainage area of 2,390- acres) is routed to and captured by the existing quarry - basin and BOR Dike #2. Refer to Figure 1. 2. Previous Studies And Topographic Mapping This Coral Canyon Preliminary Master Drainage plan analysis relies upon several previously completed drainage studies as listed below: a. Bureau of Reclamation Dike #2 and Training Dike (Devil Canyon Training Dike) Design Report and Construction Plans completed in the mid- 1960's and subsequent evaluation provided by U.S. Army Corps of Engineers and Bechtel (for CVWD), dated October 1991. b. La Quinta Golf (The Quarry) "Storm Drain Improvement Hydrology and Hydraulics Calculations ", Volume 1 & 2, prepared by The Keith Companies, dated September 15, 1993. c. "Hydrology, Hydraulics & Drainage Concept Study for Quarry Ranch Golf Course and Development Project Tentative Tract Map No. 30651 prepared by The Keith Companies, dated December 2002. d. "Technical Memorandum for West Dike System — Dike #4 Storage ' Analysis ", prepared by Pacific Advanced Civil Engineering, Inc. (PACE), dated June 2002 and approved by CVWD. In addition to the available USGS topographic mapping available, PACE obtained additional detailed topographic mapping for the area (approximately 1200 - acres) from south of the Devil Canyon Training Dike to north of the Dike #2 limits. ' This topographic mapping (see Figure provided 1 -foot contour interval in the 9 ure 2 )p flatter areas (i.e. to provide detailed basin storage volume determination for the ' Quarry Basin, Dike #2 and Training Dike) and 5 -foot contours in the steeper mountain areas as necessary to define and determine more specific drainage watershed boundaries. Coral Canyon TTM # 33444 Environmental Assessment Hydrology August Z 2005 Green Property- La Quinta 8041E Pave 2 of 6 Final Drainage System Design and Analysis (for submittal to CVWD regarding Dike #2, Training Dike and the proposed Coral Canyon development) will require additional detailed hydrologic and hydraulic modeling, sediment production estimates and geotechnical evaluations, but the available reports and topographic mapping data and preliminary analyses provided herein is sufficient to complete the enclosed master drainage plan and the necessary environmental impacts evaluation.. 3. Offsite Existing Drainage Features And Facilities As stated previously, the proposed 337 acres Coral Canyon development lies within a 2,390 -acres watershed that is tributary to BOR Dike #2. The major existing drainage features are as follows: (see Figures 1, 2 & 3 for locations of these existing drainage facilities) a. BOR Dike #2 — Approximately 5,000 -feet in length and 20 -feet in height, this dike and resulting retention basin (t 700 AF maximum storage volume) captures, retains and percolates the runoff from the tributary 2,390 -acre watershed which includes the proposed Coral Canyon development site. As part of Coral Canyon development, Jefferson Street will extend from the development, over Dike #2, and meet existing alignment. The integrity of the dike will be maintained and storage availability will remain unchanged as a result of the proposed Jefferson Street extension. As part of the Coral Canyon final drainage analysis, a detailed geotechnical and storage volume analyses (certification) of Dike #2 will be prepared and provided to CVWD for review and approval. b. BOR "Devil Canyon" Training Dike — is located to the south of the Coral Canyon development and is approximately 2,200 -feet long (north side only) and approximately 6 -feet in height. This dike was constructed by the BOR to serve several functions: (1) contain and direct flows from the 10.2 square mile Devil Canyon watershed into the larger Dike #4 retention area (2) to keep Devil Canyon flows from going into the Dike #2 retention basin and over taxing the capacity of the Dike #2 and the associated retention basin. Through field observation and review of current topographic mapping (for the past + 40 years of history), the self - scouring dike confines the flow into a single channel therefore performing as it was designed. As part of the Coral Canyon final drainage analysis, a detailed geotechnical analysis, hydraulic capacity and slope stability analysis will be prepared for the Devil Canyon Training Dike and provided to CVWD for review and approval prior to occupancy of homes within Coral Canyon Community. The Keith Companies' 2002 Quarry Report Drainage Analysis provided preliminary Training Dike evaluation and determined PACE Coral Canyon TTM # 33444 Environmental Assessment Hydrology August Z 2005 Green Proaerty— La Quinta 8041E Page 3 of 6 that the facility is competent and satisfactorily conveys the standard project flood (SPF) Devil Canyon watershed flows without over - topping or eroding the Training Dike, thus protecting the Coral Canyon project site from the Devil Canyon flows. c. Existing Quany Retention Basin — As a result of years of quarry excavation, a large man -made retention basin now exists within the "Quarry Ranch Project Golf Course" area which is located immediately to the north of the proposed Coral Canyon development. This man -made retention basin (Quarry Basin) has a storage volume in excess of 500 -acre feet which is more than the 460 AF of runoff (SPF storm event) from drainage watershed area "B" (see Figure 1). This is significant as the Quarry Basins at 500 AF has nearly as much storage capacity as the Dike #2 storage volume of t 700 AF. The SPF runoff volume to the Dike #2 basin from watershed Al and A2 (see Figure 1) is t 491 AF. The Quarry Basin captures runoff from 1152 -acres of the 2,390 acre total drainage area (nearly 50% of the drainage area never makes it to the Dike #2 basin as it is captured in the Quarry Basin). d. QuaU Ranch Project Diversion Channel — Excavated with the construction of the Quarry (TTM 30651) Development project entry road, a trapezoidal channel with a t 20 -foot bottom exist along the north boundary of the Coral Canyon project. The existing earthen channel starts (downstream end) at the northeast corner of the Coral Canyon boundary and extends west, running just north of the Coral Canyon property line for a distance of approximately 2000 -feet. The channel was designed by the Keith Companies with the Quarry Development Project to route the runoff from the area south of the channel (Coral Canyon site) to the Dike #2 retention basin without going through the Quarry Development Project. The Quarry and Coral Canyon development parties have an agreement to share the use of the channel and with the final design of the Coral Canyon project, the channel design and construction will be completed. 4. Offsite — Hydrology & Hydraulics Figure 1 of the enclosed exhibits indicates three major watershed sub - basins tributary to the BOR Dike #2 (the proposed 238 -acre Coral Canyon development boundary is in two of the watersheds, but all of the proposed Coral Canyon . Development is within the "A2" watershed). The drainage watershed areas and approximate SPF and 100 -Year runoff values are show in Table 1 below. PACE Coral Canyon TTM # 33444 Environmental Assessment Hydrology August 2, 2005 Green Property- La Quinta 8041E Pane 4 of 6 Table 1 - Drainage Area Runoff` Flow and Volume (SPF & 100 -Year Eventsl . z' •e . e°� � e F � a S. Ru ear Al 960 1,923 371 1,355 112 A2_ 301 640 120 499 36 B 1152 2,361 460 1,539 139 Total Runoff Volume (AF) 951 287 * Runoff volume and flowrate values are approximated, final project design and analysis will determine actual values and include sediment yield analysis. ** Drainage area W" includes the portion of proposed Coral Canyon TTM #33444 project that will have housing and related land development. Note: Drainage Areas "Al" & "A2" are tributary and drain to the retention basin behind BOR Dike #2 (Existing Retention Basin "A "), which has a storage volume of +700AF and captures 100% of the tributary runoff from the 100 -Year and the SPF events. 2Drainage Area "B" is tributary to the existing excavated Quarry which has retention capacity of +500 AF which is more than the SPF runoff volume from the "B" drainage area (430 AF). Therefore, 100% of the runoff from drainage area "B" is captured within the Quarry (Retention Basin "B" and does not impact the Retention Basin "A" at Dike #2). 5. ;Onsite — Hydrology & Hydraulics a. Existing Hydrology Stormwater from the Coral Canyon onsite watershed drains to the north and east (See Figure 3), via a system of natural desert. The washes confluence at the northeast part of the watershed and all stormwater runoff from the watershed concentrates at the northerly extent of the project and discharges to the existing offsite Quarry Road Channel, just north of the project boundary. The site topography is composed of broad canyon surrounded by foothills. b. _Post-Development Hydrology The proposed Coral Canyon development includes grading in the easterly half of the project boundaries. Stormwater will be collected and conveyed from the west, south and east in a series of man -made drainage channels to the northeast. In the developed condition, the watershed drains to the same location as in the existing condition (the northeast). c. Onsite Drainage Improvements - Hydraulics As shown on attached Figures 3 & 4, the proposed project drainage improvements will consist of the following: 1) Upstream sediment / debris basins to capture sediment from debris laden flows. -PACE Coral Canyon TTM # 33444 Environmental Assessment Hydrology August 2, 2005 Green Property— La Quinta 8041E Pacae 5 of 6 2) The main drainage channels to convey runoff through site will be naturalized channels utilizing rock and boulders to stabilize side slopes and invert where necessary. These channels will most likely include rock grade stabilizers or drop structures to reduce flow velocities to non- erodable levels ( <7fps). The grade stabilizers and drop structures may require concrete grouting to minimize erosion. The drop structures will be of the low type 3 to 5 feet in height. 3) Minor collection channels at the toe of the mountain to collect runoff prior to entering rear yards. 4) The project channels include trail systems which will be located in channel invert where possible and adjacent to the channel elsewhere. Refer to Figures 3 & 4 for the location and dimensions of the proposed project drainage features. Based upon the maximum velocity of 8 fps, maximum depth of flow of 2.0 feet and the short duration hydrograph peaks ( <20 minutes) public safety within development is not an issue related to drainage. All of the project runoff will be directed to the pre- existing discharge location (i.e. Dike #2 retention area) via the shared "Quarry Ranch Coral Canyon development' diversion channel. Final design analysis will determine as required channel conveyance and erosion protection. The sections and details shown on Figure 4 will be in substantial continuance with final design. 6. Results — Pre VS. Post Development Hydrology Pre - developed and post - development hydrology was analyzed using the modified rational method incorporated into software developed by Advanced Engineering Software (AES). All calculations were performed in accordance with the Riverside County Flood Control and Water Conservation District Hydrology Manual. Table 2 shows the stormwater runoff from the watershed, during a 100 year storm event, for the existing and post - development conditions. It is worthwhile to note that the peak flow and the time of concentration for the watershed are not altered greatly from that of the existing condition, and the location of the discharge remains unchanged. Note that the increased impervious cover in the developed condition results in a 5% increase in peak discharge from the developed watershed. Additionally, the time of concentration. for the developed condition is decreased by 2.5 %. -PACE Coral Canyon TTM # 33444 Environmental Assessment Hydrology August 2, 2005 Green Property - La Quinta 8041E Pape 6 of 6 Table 2 - Watershed Discharge, and Time of Concentration (TJ for the Existing Condition and Post - Development Condition 7. Conclusion Although any increase in runoff volume or peak flow rate from pre to post developed condition for the Coral Canyon project site will be insignificant. Drainage mitigation, if necessary, may be provided through one or more of the following options which are all part of the proposed project drainage master plan: 1) Sediment basins within the Coral Canyon project site . 2) Decreased sediment. production from the Coral Canyon site 3) Onsite retention basins 4) Excavation within Dike #2 retention area to increase storage capacity In conclusion, the Coral Canyon project final drainage analysis and design will verify the preliminary finding of no significant impact to Dike #2 or ponding within the Dike #2 retention basin. Neither the Coral Canyon development nor the proposed Jefferson Street re- alignment will adversely impact Dike #2 and Dike #2 Retention Basin. Also, it has been shown that the Dike #2 maximum (SPF) ponding elevation is below elevation 530 which is 15 feet below the minimum Coral Canyon site elevation of 555. Therefore, the proposed Coral Canyon site is not within the potential flood hazard zone of the Dike #2 impoundment area, nor is the proposed project expected to otherwise adversely affect the BOR Dike #2 impound area or adjoining development. Additionally, preliminary analysis of BOR Devil Canyon Training Dike has shown ° gr- J C 0 "4i.G la -Y findings. bya.'"} T E 7. Conclusion Although any increase in runoff volume or peak flow rate from pre to post developed condition for the Coral Canyon project site will be insignificant. Drainage mitigation, if necessary, may be provided through one or more of the following options which are all part of the proposed project drainage master plan: 1) Sediment basins within the Coral Canyon project site . 2) Decreased sediment. production from the Coral Canyon site 3) Onsite retention basins 4) Excavation within Dike #2 retention area to increase storage capacity In conclusion, the Coral Canyon project final drainage analysis and design will verify the preliminary finding of no significant impact to Dike #2 or ponding within the Dike #2 retention basin. Neither the Coral Canyon development nor the proposed Jefferson Street re- alignment will adversely impact Dike #2 and Dike #2 Retention Basin. Also, it has been shown that the Dike #2 maximum (SPF) ponding elevation is below elevation 530 which is 15 feet below the minimum Coral Canyon site elevation of 555. Therefore, the proposed Coral Canyon site is not within the potential flood hazard zone of the Dike #2 impoundment area, nor is the proposed project expected to otherwise adversely affect the BOR Dike #2 impound area or adjoining development. P CE Additionally, preliminary analysis of BOR Devil Canyon Training Dike has shown that the proposed Coral Canyon project is not subjected to potential flows from the Devil Canyon watershed. Final Geotechnical hydrologic and hydraulic ' analyses will be provided to CVWD and FEMA to confirm and finalize these findings. P CE % 24 21 W7 WW 'szI,,F i) i m9 m CD 00 Ol 2S 00 O FIV Cf) ME CD CD 00 cn F- LLJ 0- II CL au 11: 1 u I w -!2 LLJ C5 cr) C5 0- 00 F V) v II -/3 o cc I *4 VA CANYON A = 10.2 Mj2 QsPFI = 9,032 cfs VOLsFf = 2,249 of Qloa = 4,043 cfs VOLioo 607 of Is TTM #33444 ffvni, :PF = 120- nf, I IS 15 1", r Qioo = 499 Q100 '� 1-1 - loo n AR 1114 530 525 520 r z 0 � 515 a w w 510 505 500 495 BASIN 2A CUM ULATIVE VOLUME vs. ELEVATION 0.00 100.00 200.00 300.00 PF .A--1.5miI Qrr - 1,923 ch VOLxw • 371 3f NO - 1,355 ch VOL= - 112 of Fim I i' y 530 525 520 z 0 Q 515 J W 510 505 500 400.00 500.00 600.00 700,00 800.00 800.00 CUM ULATIV E V OLLNIE( 495 BASIN 2B (Quarry) CUM ULATIV E V OLUM E vs. ELEVATION EYIST /NG °RETEN7%tW, z t I r I n I I I F V) CD �o o U� 0 LH 0 E >< 0 558 ROAD 554 ................... 550 0 HIS= EXISTING GRADE 618-1 614 610 0 15' MIN kL--i GRADE — ± 20' TYP MAJOR CHANNEL (PROPOSED) SCALE: 1"=10' Oloo = 257 cfs d = 1. 5 ft v = 7.0 fps s =2% n= 0.035 z = 3:1 EXISTING GRADE/SLOPE c-li CONCRETE (OR OTHER* SOOZ `£Z gomW 909Z6 HO `autnal 00£ ol!nS `lmd almodaoz) It, spt,oissoiD utgzn Xq pawdaid ;uawdojaeaQ lv9uapisag uejd agtaadS uaa i!) aq; .io; S!SAInud OWV.i,L pasnoo3 suodag IeoiugoaZ 90't,Z'8/d'3 bbb££ W U muino wl 3o latD /N.L March 23, 2005 Mr. John Criste TERRA NOVA PLANNING & RESEARCH, INC. 400 S. Farrell Drive, Suite B -205 Palm Springs, CA 92262 Focused Analysis Development Dear Mr. Criste: INTRODUCTION RECEIVED MAR 2 5 2005 Residential The firm of Urban Crossroads, Inc. 'is please to submit this focused analysis for the proposed Green Specific Plan. The evaluation is based upon review of relevant previous study efforts and current proposed land uses for the Green Specific Plan. The purpose of the analysis is to determine the appropriate roadway cross - section for the proposed northerly portion of the Jefferson Street loop connecting Avenue 58 and Avenue 62. RELEVANT PREVIOUSLY PUBLISHED REPORTS Previously published reports that are directly relevant to the current focused analysis include a traffic study prepared for the Travertine and Green Specific Plans (Endo Engineering, 1994) and the City of La Quinta General Plan Update Traffic Study (RKJK and Associates, 2000). Each of these studies included analysis that is applicable to the focused evaluation. In October of 1994, Endo Engineering prepared a traffic study for the Travertine and Green Specific Plans. The Endo Engineering traffic study evaluated the site access for Mr. John Criste ' TERRA NOVA PLANNING & RESEARCH, INC. March 23, 2005 Page 2 both projects through the construction of Jefferson Street Loop with connections to Avenue 58 and Avenue 62 at Madison Street. Exhibit A illustrates the location of the proposed Green Specific Plan and the Travertine Specific Plan with the proposed Jefferson Street loop. The more recent General Plan Update Traffic Study evaluated conditions in a more general evaluation of citywide traffic. A review of the results of the two studies is presented in terms of land use, trip generation, and trip distribution and traffic assignment. LAND USE The Green Specific Plan analyzed in the Endo Engineering traffic study consists of a master planned resort community with a variety of single family detached residential uses. Minor changes have been proposed to the ' Green Specific Plan project land use description since this study was prepared. As originally approved, the project would provide a total of 277 resort homes, with an overall density that is slightly less than one unit per acre. The current development plan (Tentative Tract Map No. 33444) would provide approximately 240 single - family dwelling units. As currently approved, the Travertine Specific Plan consists of a master plan resort community with a balanced mix of land uses. The proposed Travertine project would provide a total of 2,300 resort homes with an overall density of 2.5 units per acre. Two 18 hole golf courses, a 27.7 acre hotel /conference center and a 10 acre neighborhood commercial are also.included in the Specific Plan. Based on a review of the City of La Quinta General Plan Update, the land uses .in the General Plan show approximately 2,800 dwelling units with adjoining uses such as resorts, public facilities, golf courses and commercial sites. The number of dwelling units in the City of La Quinta General Plan is approximately 10% higher than in the Travertine and Green Specific Plans. All other uses are generally consistent. 1 Mr. John Criste ' TERRA NOVA PLANNING & RESEARCH, INC. March 23, 2005 Page 3 GREEN SPECIFIC PLAN AND TRAVERTINE SPECIFIC PLAN DAILY TRIP ' GENERATION ' The approved Green Specific Plan residential development is projected to generate 2,640 trip -ends per day. The trip generation is based on standard single - family dwelling unit ' rates, with no credit for retirees or part-year residents; if a trip rate of 4 trips per dwelling units are applied (consistent with senior /retired housing /part year residents) the project ' traffic could be about 1,100 trips per.day. The Travertine mixed use specific plan is projected to generate 27,820 trip -ends per day. The 27,820 trip -ends per day do not ' account for trip overlap on site (i.e. trip interactions on -site between the residence or the hotel and the commercial uses). Per the Endo traffic study, the Travertine Specific Plan ' trip generation accounting for internal interaction is 23,820 external trip -ends per day. Based on review of the City of La Quinta General Plan Update, the trip generation for both projects is approximately 20,000 trip -ends per day. This is based on the estimated areas of the model Traffic Analysis Zones (TAZs) that represent the Travertine and Green Specific Plans. Similarly, the Endo Engineering traffic study trip generation for the ' Travertine and Green Specific Plans is approximately, 30,000 trip -ends per day. The City of La Quinta trip generation does take credit for retirees or part -year residents, while the ' trip generation for the Travertine and Green Specific Plans is taken from the ITE rates and do not account for retirees or part-year residents. Therefore, the traffic estimates used for ' the Travertine and Green Specific Plans traffic study are more conservative. PROJECT TRIP''DLSTRIBUTION�,AND ASSIGNMENT `The Endo Engineering Specific Plan traffic study developed project trip distribution and traffic assignment characteristics based on a detailed review of the planned roadways and the location of the various :land uses within each Specific Plan. Based on the Endo Engineering traffic study, the Green Specific Plan will take primary access north on Jefferson Street to Madison Street via Avenue 58. Virtually all of the Green Specific Mr. John Criste ' TERRA NOVA PLANNING & RESEARCH, INC. March 23, 2005 Page 4 Plan traffic will utilize this route per the project specific traffic analysis. The Travertine ' Specific Plan will have primary access to Madison Street via Avenue 62, with approximately 4 percent (around 900 daily trips) from the Travertine Specific Plan itraveling north on Jefferson Street to the Green Specific Plan or to Madison Avenue via Avenue 58. Exhibit B illustrates the daily traffic volumes from the Travertine and Green ' Specific Plans traffic study on Jefferson Street (Average Daily Traffic volumes). Exhibit. C depicts the anticipated traffic volumes on Jefferson Street from the most recent.General Plan update traffic study. The General Plan traffic study trip distribution tis based on a more generalized traffic model representation that does not account for the detailed locations of the land uses for each of the individual Specific Plans. This ' more generalized analysis suggests that a much higher percentage of the Travertine Specific Plan traffic would take the more circuitous Jefferson Street Loop' to travel to ' destinations located to the north. Based on our .review of the input data and assumptions contained in each of the studies, Urban Crossroads, Inc. staff would expect that the traffic assignment patterns ' projected in the more detailed Specific Plan traffic study are more accurate and should be used to evaluate the project(s) traffic pattern(s) and resulting roadway sizing. ADOPTED AND RECOMMENDED GENERAL PLAN ROADWAY SYSTEM Exhibit D shows the City of La Quinta General Plan Circulation Element. Exhibit E shows the City of La Quinta general roadway cross - section for a Secondary Arterial and a 'Collector. The currently adopted City of La Quinta General Plan roadway system identifies Jefferson Loop as a Secondary Arterial, with an 88 foot, four lane undivided ' cross- section. -Based on the buildout daily traffic volumes shown in the Travertine and Green Specific Plans traffic study, a total of 3,730 daily trips are expected to access Jefferson Street ' north of the Green Specific Plan. The capacity for a Secondary Arterial is 28,000 daily Mr. John Criste TERRA NOVA PLANNING & RESEARCH, INC. March 23, 2005 Page 5 trips and the expected volume to capacity ratio is approximately 0.13 (3,730/28,000). ' The Jefferson Street capacity far exceeds the projected daily volume. The daily capacity for a Collector is 14,700 daily trips, therefore the expected volume to capacity ratio on a Collector is 0.25 (3,730/14,700), well below the recommended volume to capacity ratio of .90 defined in the City of La Quinta General Plan. Table 1 summarizes the volume to capacity ratio analyses. SUMMARY Based on the analysis presented in this focused evaluation, it is recommended that Jefferson Street between Avenue 58 and the south boundary of the Green Specific Plan be downgraded from a Secondary Arterial to a Collector. Given the other development that is likely to use the Jefferson Loop, along the subject project, the capacity of this roadway should be adequate to serve the future traffic demand. Urban Crossroads, Inc. is pleased to provide this focused analysis evaluation for the proposed project and roadway system. If you have any questions regarding this analysis or require further information, please do not hesitate to call us at (949) 660- 1994 x210. Sincerely, URBAN CROSSROADS, .INC. Carleton Waters, P.E. Principal CW:RA:jb JN- 02302 -03 Attachments CITY OF LA QUINTA GENERAL PLAN PROPOSED ROADWAY DAILY DAILY ROADWAY CAPACITY VOLUME ROADWAY CAPACITY VOLUME ROADVIIAY. _;.:::,- ._:.: °:- CLASSIFICATION (ADT) (ADT) V /C' CLASSIFICATION (ADT) (ADT) V /C' Jefferson St North of they ! Green SpecificPlan „ .._Seconda ...Arterial 28;000 3,730 0.13 Collector 14,700 3,730 0.25 . .. ;,I g�' �! �1•i •.may y 1' �� � _�'It ya_ 'Y "T I 2 •„•'4 P7gt- e}I � N.� t; .. Ti �§ 5T ,� K ST AV 62ND AV 1 All-t TiAV '4 �:• _ � �r2 �C his 1.: x • LEGEND: • .. � '�� •- .� -:y� I �,GREEN-SFECIFIC�PLAN �•_,• _..�, TRAVERTINE SRECIEIC PLAN I* QUINTA CITY LIMITS w EXISTINGsROAD , - - -- - -- UNPAVEUROA. D 0 1;900 31800 — — — PROPOSED Feet ,I GREEN & TRAVERTINE SPECIFIC PLANS, La Quinta, Califomia - Iq:ex -a.mxd URBAN CROSSROADS EXHIBIT 'B TRAVERTINE AND GREEN SPECIFIC PLANS AVERE DAILY TRAFFIC (ADT) AG 900 81ST AV f •. Hwy'- ilU i`'�v 3 "�''. 'i `q� i � Z • �� , I •� P,LA �'' ~fix M."� > .. pr i . i � • ' `�.�i�''k4 - �w,` ��s�'^ �� os' , r'� 62ND AV , ice' ,t 1. L 1��f,,,, ' �'F.�a�ua ➢ t 1 C h ... .. .x -. z� 714 AV • •. �' � :LEGEND: ' N:,SFECIFIG PLAN, GFtEE , — h SOURGE':T, V fRAVERTINE'.SP..ECIFIC >P.,LAN ERTINE AND;�GREENSP.ECIFIC. P,LANSYTRAFFIC IMPACT.STUDY.: — ' (ENDO. ±ENGINEERING :OCTOBER�1999) LAOWINTACITYLIMITS EXISTING?ROAD - - -- UNPAVED`ROAD 0 1;900 3;800 — — — PROPOSED Feet 31720 GREEN/TRAVERTINE COMBINED DAILY TRAFFIC VOLUMES URBAN GREEN & TRAVERTIN E SPECIFIC PLANS, La Quinta, Califomia - 00:ex -b.mxd CRO55ROPO5 i EXHIBIT C CITY OF LA QUINTA GENERAL PLAN AVERAGE DAILY TRAFFIC (ADT) pit} 4' e F 3 S y h j •r. INf f 54 � 62ND AV ' 7 h NONE- -M a r 5• �j s +* - -- - -_ - -_. - - - - -- ----- --- - - - - -- -- - - - - -- —SFtii 84 AV ' ... . . • ._ .LEGEND:. 1 • GREEN;SPECIFICPLAN SQURCE iCITYtOF LA QUINTA GENERAL PLAN 1. ''.. ' .� TRAVERTINE'SPECIFIG'P,LAN UPDAT,E:TR RFIG%TUDY, �- tEPTEMBER'2000" — — ' - LAW NTA.CITY "LIMITS EXISTING: ROAD ' - - - -- UNPAVED'ROAD 0 1;900 31800 — — — PROPOSED Feet 8;600 GREENffRAVERTINE COMBINED, DAILY TRAFFIC VOLUMES` ' GREEN & TRAVERTINE SPECIFIC PLAN URBAN S, La �umta, Calif�mia - I�:ext.mx� i � I- EXHIBIT C CITY OF LA QUINTA GENERAL PLAN AVERAGE DAILY TRAFFIC (ADT) pit} 4' e F 3 S y h j •r. INf f 54 � 62ND AV ' 7 h NONE- -M a r 5• �j s +* - -- - -_ - -_. - - - - -- ----- --- - - - - -- -- - - - - -- —SFtii 84 AV ' ... . . • ._ .LEGEND:. 1 • GREEN;SPECIFICPLAN SQURCE iCITYtOF LA QUINTA GENERAL PLAN 1. ''.. ' .� TRAVERTINE'SPECIFIG'P,LAN UPDAT,E:TR RFIG%TUDY, �- tEPTEMBER'2000" — — ' - LAW NTA.CITY "LIMITS EXISTING: ROAD ' - - - -- UNPAVED'ROAD 0 1;900 31800 — — — PROPOSED Feet 8;600 GREENffRAVERTINE COMBINED, DAILY TRAFFIC VOLUMES` ' GREEN & TRAVERTINE SPECIFIC PLAN URBAN S, La �umta, Calif�mia - I�:ext.mx� Fit . . . . . . . . . . . F4 Cr: P WWI OK ' EXHIBIT E CITY OF LA QUINTA � GENERAL PLAN ROADWAY CROSS - SECTIONS SECONDARY ARTERIAL 12' 14' 12' 88 12' 12' 14' 112' SOURCE: CITY OF LA-QUINTA GREEN & TRAVERTINE SPECIFIC PLANS La Quinta California - •Iq \xsections dwa URBAN c ossao os ' (FOUR LANES UNDIVIDED, NO PARKING) COLLECTOR 11' 8' 12' 74 12' 12' 8' 11' SOURCE: CITY OF LA-QUINTA GREEN & TRAVERTINE SPECIFIC PLANS La Quinta California - •Iq \xsections dwa URBAN c ossao os .( TWO LANES U,NDIVIDED,..WI.TH BIKE,LANE) SOURCE: CITY OF LA-QUINTA GREEN & TRAVERTINE SPECIFIC PLANS La Quinta California - •Iq \xsections dwa URBAN c ossao os