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191114 Section 44.0 INFRASTRUCTURE PLAN TRAVERTINE SPECIFIC PLAN AMENDMENT – 2019 Page 4-1 INFRASTRUCTURE PLAN This Section describes the infrastructure development plan, requirements and implementation as well as the general intent and comprehensive framework of the infrastructure development within the Travertine development. 4.1 Circulation Plan Description Exhibit 4.1 illustrates the conceptual Circulation system proposed to serve the Travertine community. The community is proposed to be served by two access points: (1) the southerly extension of Jefferson Street as a Modified Secondary, south of Avenue 58, and (2) the westerly extension of Avenue 62 as a Modified Secondary, west of Monroe Street and a Secondary Arterial, east of Monroe Street. In the Construction Phase 1 stage, Avenue 62 will cross Dike #4 and extend westerly towards the Travertine project boundary. This crossing will require a license, secured by the City of La Quinta, and approved by the Bureau of Reclamation (BOR). Project design details for the proposed circulation plan will be completed far enough for the BOR to determine the project impacts and utilities. This spine roadway, which curves through the project, as shown on Exhibit 4.1. Jefferson Street will be extended south of Avenue 58 through the Coral Canyon development and through Travertine to meet the extension of Avenue 62, dependent upon the timing of development of Coral Canyon and approvals through BOR and Bureau of Land Management (BLM). As illustrated in Exhibit 4.1, The spine road will be a Modified Secondary road configuration between the northern project boundary (as the southerly extension of Jefferson) and the eastern project boundary (as the westerly extension of Avenue 62). Avenue 62 will be improved as a Modified Secondary east of the project to Monroe Street. The Travertine community land uses are oriented on both sides of the Jefferson Street / Avenue 62 spine roadway, with local loop collector roads emanating from the spine roadway via round-abouts to provide access to the neighborhoods as illustrated on Exhibit 4.1. A detail of the round-about is shown in Exhibit 4.2 These streets will have a typical right-of-way of 70 feet, with curb to curb distances of 40 feet with 9- foot curb adjacent landscaped parkways and a 6-foot wide pedestrian walkway on both sides. Exhibits 4 .3 and 4.4 identify the typical street cross sections and standards. Local roads are also planned to be utilized and will be comprised of a curb to curb dimension of 32 feet, which allows for parking on one side of the street and 36 feet, which allows for parking on both sides of the street. These residential local roads will provide a landscape easement at a minimum of 12 feet on each side of the street and 15 feet to residential building. An access road will be dedicated for entry to Section 5 for any future uses. The road will connect from the loop road of the Travertine project to Section 5, that will be defined as an easement and entitled by the Applicant to allow access from the project, during the same Construction Phase as the loop road is built. The project will be gated for privacy. These gates will be located at the entrances to the community via Jefferson Street or Avenue 62. Exhibit 4.1 shows the location of the gates off Jefferson and the typical gate configuration is shown on Exhibit 4.5. The Resort / Spa entry at Jefferson will also be gated. Gating of individual neighborhoods within the residential Planning Areas, is permitted. The location of any proposed gates will be reviewed and approved by the City as part of either a tentative tract map application or as a part of a site plan review application. DRAFT 4.0 INFRASTRUCTURE PLAN TRAVERTINE SPECIFIC PLAN AMENDMENT – 2019 Page 4-2 Exhibit 4.6 exhibits the typical landscape and monumentation of the entries to the development from both Avenue 62 and Jefferson Street as well as typical entry gates for the residential portions of the development off of the spine road and on the loop road entries of the project. The final drainage conveyance and retention/detention onsite will determine the placement and extent of bridges and/or culvert crossings needed to maintain all-weather access for all roadways. The Construction Phase 1 stage will include one large detention facility of 14.1-acres that will be located at the south easterly edge of the project adjoining the prolongation of Avenue 62, and will outlet water into the impound area against Dike No. 4. In the Construction Phase 1 stage, prior to any building construction, the project will need to have the necessary fire flows to all hydrants in addition to providing two points of access. The project will provide all wet and dry utilities from Avenue 62 to the point of connection for various builder phases. The project will have to adequately secure all common area landscape prior to construction. 4.2 Water Coachella Valley Water District has jurisdiction over domestic water service to the Travertine project. Currently, domestic water service lines exist in the area of the intersection of Avenue 60 and from Jefferson extension and Avenue 62. During the Construction Phase 1 stage, water utilities will be connected prior any construction. One well will be constructed during the Construction Phase I stage, located off the Travertine project site. Currently there are ongoing discussions with local parcel owners, CVWD and developers, to locate the future offsite well sites. The well sites necessary to serve the project have been analyzed by CVWD the initial number of well based on the total acreage of the project is equivalent to 9 well sites. The number of well sites that will actually be needed to serve the site come from a development agreement between CVWD and the land owner based on extenuating circumstances for providing alternative means and measures of water service to not only to the project but to the region, the process for acquisition of well sites will be done by a private purchase by the land owner, where the environmental clearance coincident with the project will be generic for all typical well sites located within CVWD’s jurisdiction. As the site-specific well sites are purchased by the land owner ultimately dedicated to CVWD, any unique conditions not covered by the EIR for the overall project will then be covered supplementary to that document. Exhibit 4.7 identifies the conceptual on-site water service facilities that are required to provide domestic water to the community. As noted above, wells may be required to be improved and/or constructed to serve the project site, with one well operable and available prior to the issuance of the first Certificate of Use and Occupancy. Additional facilities will include two water reservoirs and booster stations to collect the well water and store it at elevation to provide the required water pressure for the site. The project site will be served with a thirty-inch main line within Jefferson Street/Madison Street alignments. Twelve-inch and smaller lines will then feed off the main line to serve the individual developments along these public streets. Precise locations, alignments, and sizes of water service facilities will be determined at the Tentative and Final Map stage of development, per City and Coachella Valley Water District regulations and standards. Irrigation water for the golf course and landscaping is intended to be non-potable Coachella Canal water that is available to the site. Infrastructure will be installed in the Construction Phase 1 stage to DRAFT 4.0 INFRASTRUCTURE PLAN TRAVERTINE SPECIFIC PLAN AMENDMENT – 2019 Page 4-3 convey the water to the site and to ensure that the non-potable water remains separate from the potable water system. In the event that this water is not available to the Travertine development, the onsite irrigation wells will be utilized for future irrigation. 4.3 Sewer The project site is presently served by the Coachella Valley Water District. Plans to extend the sewer mains along Avenue 62 and Jefferson Street to the project are in development. The conceptual on-site sewer facilities and improvements are shown on Exhibit 4.7. The facilities are comprised of a series of eight-inch sewer lines serving the individual developments and flowing into the main sewer line located within the Jefferson Street/spine road alignment. The main sewer line increases in size as it proceeds eastward, ranging in size from eight inches on the west side to 15 inches at Madison Street, where the line exits the project site. Final design criteria, location, alignment and sizing of sewer facilities will be determined at the tentative and f inal m ap stage of development, pursuant to the processes and specifications of the City and Coachella Valley Water District. 4.4 Conceptual Grading and Drainage Plan The project site slopes gently in a downslope direction from west to east and is subject to two kinds of drainage conditions: alluvial fan flow and incised drainage corridors along inactive fans. The primarily existing drainage condition is alluvial fan flow; eight canyon drainages contribute runoff to the overall project site. The major contributors of runoff to the planned development area are Devil Canyon, Middle North Canyon, Middle South Canyon, and Rock Avalanche Canyon. Flows from these canyons and other drainages continue across the site and ultimately drain into the reservoir created by Dike No. 4. Exhibit 4.8 and 4.9, demonstrates consistency with the Hillside Conservation regulations of the City in that slopes greater than 20% are avoided. 4.4.1 Drainage Plan The approach to the management of drainage in the Specific Plan is to concentrate the planned development within the inactive fan areas where possible, and provide a perimeter flood protection system around the development site to provide the necessary level of protection. The primary watershed solution (Exhibit 4.10 and 4.11), illustrates flows being conveyed around the site in order to pass flows to the downstream off-site areas along Dike No. 4 in a manner that avoids flooding risks to the downstream areas. After analysis of various options, it is determined that the most challenging drainage condition to manage through the site is the potential for active alluvial fan flow conditions. Alluvial fan flows potentially impact the entire western and southern edges of the planned development area. To manage this condition, it is determined that a perimeter flood protection barrier will be used along the western and southern boundaries. The barrier will consist of a raised edge condition with a slope lining to protect against scour and erosion. The edge will be elevated above the water surface elevations associated with the 100-year storm event, and will be designed based on a worst-case flow scenario assuming an active alluvial fan condition. These flood protection barriers solve four problems: they will intercept alluvial fan flows, incised canyon flows, and will control associated debris load; and they will allow planned conveyance facilities around the project. The proposed conveyance features will direct off-site flows, once intercepted by the barriers, around the perimeter of the development by means of open channel swales to safe outlets on the north and south sides of the development. The site itself will be raised along these edge barriers to avoid the creation of levee like conditions. DRAFT 4.0 INFRASTRUCTURE PLAN TRAVERTINE SPECIFIC PLAN AMENDMENT – 2019 Page 4-4 The offsite run-off from Devils Canyon will be distributed on the north through the existing Guadalupe Dike system to Dike No. 4. Offsite watershed runoff from the Middle Canyons (North and South) and Rock Avalanche Canyon will be intercepted and conveyed along the southern portion of the site to Dike No. 4 south of the proposed Avenue 62 crossing. As seen under the primary drainage solution, Exhibit 4.10, flows will be conveyed around the site on the west and south boundaries and re-distributed on the east along Dike No. 4. The Conceptual Hydrology plan for the Travertine development, as illustrated in Exhibit 4.10 ensures that all residents of the community, as well as downstream facilities and properties, will be protected from periodic flooding that is experienced in the region. Exhibit 4.11 identifies the existing flows that come on to the project site, generally from the south and west. The diagrams also identify the various conceptual storm facilities (perimeter barriers, on-site drainage) that are required to transmit storm runoff flows. More detailed engineering and design, consistent with design standards established by the City and the Coachella Valley Water District, are completed at the final map stages of development, resulting in the precise location, alignment, and sizing of all drainage facilities. The Existing Hydrology is seen in Exhibit 4.10. 4.4.2 Stormwater Management Plan Before any construction, a stormwater management plan must be created and finalized as part of the Construction Phase I stage. For the stormwater management plan, the applicant must finalize the calculation of Standard Project Flood (SPF), 100-year and 25-year runoff rates for on-site and off-site drainages. The project must have hydraulic analysis utilizing refined runoff rates to determine design water surface elevations and flow velocities along the perimeter flood barriers, Guadalupe Canal, and Dike No. 4; in addition, the storm management plan must accomplish the following: 1. Evaluation of flow velocities on a reach by reach basis to determine: a) lining requirements in terms of materials and lining thickness, b) potential for deposition of sediments, and c) the need for channel stabilization to control scour. 2. Create adjustments to flood protection system configurations (in terms of barrier and levee heights and bridge crossing widths) and refine the hydraulic analysis. Determine the optimum configuration of channels, barriers, and levees with necessary containment and erosion control structures which will provide the 100-year flood protection and blend effectively with natural environment (where appropriate) and the proposed development. 3. Prepare detailed designs and specifications for facilities including containment levees, erosion protection (natural appearing where possible), and channel stabilization structures as may be required. Consideration of re-naturalization, preservation of natural features, and reduction of visual impacts will be made during the various steps. In addition, all drainage facilities for on-site drainage will be designed following the same process. The objectives for the flood control and drainage facilities throughout the Travertine properties are: DRAFT 4.0 INFRASTRUCTURE PLAN TRAVERTINE SPECIFIC PLAN AMENDMENT – 2019 Page 4-5 • Protect all buildings from damage from the 100-year storm in any of the drainage areas that cross or are within the property • Safely discharge all flows leaving the property • Control sediment, and manage debris flow around the site • Assure the reliable operation of each drainage feature through a full range of flows from low flows to the design event • Where levees, channels, or embankments are used, provide adequate freeboard • Assure that embankment, levee, and channel lining or stabilization is used to control scouring of channel inverts or side slopes • Re-naturalize, landscape and or use “naturalized contour grading” where feasible and appropriate. 4.4.3 Grading Plan Given the complexities associated with controlling alluvial fan flow and the sloping nature of the site, creative grading techniques will be necessary. Exhibit 4.7, Grading Plan and Exhibit 4.8, demonstrates consistency with the Hillside Conservation regulations of the City in that slopes greater than 20% are avoided. The area planned to be graded is generally comprised of slopes of between 0% and 10%. The site is elevated and grading will potentially be visible to areas north of the site. The grading will maintain the natural orientation and drainage of the land by implementing varied contoured grading at 3:1 to 5:1 ratios in conformance with natural terrain. The sections will demonstrate day-lighted slopes to natural, where natural slopes meet the graded slopes, as well as relationships between typical pads, proposed surface improvements, channels, trails, proposed golf course grading, reservoir pads, etc. at various locations throughout the project. All grading will be performed under the supervision of an Engineering Geologist to guarantee a stable site for the intended use. Landscaping and irrigation facilities will be required for all graded slopes greater than 5 feet in height or areas susceptible to erosion. Track mounted portable crushers will be used directly on site, to allow rock crushing to exact grading specification. Rock crushing on site will eliminate the need for exporting rock and importing good fill material while also avoiding traffic congestion, providing dust control, avoiding damage to roads and tracked mud. Future final maps will include detailed grading plans and supporting engineering designs and analyses for review and approval by the City of La Quinta. All areas adjacent to General Plan designated open space areas shall comply with the requirements of Section 9.110.070 and 9.140.040 (Hillside Conservation Regulations) of the Zoning Ordinance. 4.5 Utilities Southern California Gas Company provides natural gas to the project site. Electric service to Travertine will be provided by Imperial Irrigation District. An offsite substation will be required for the Travertine development and will be constructed during the Construction Phase I stage. Currently there are ongoing discussions with local parcel owners, IID and developers, to locate the future offsite substation location. All required off-site parcels required for utilities will be chosen to fit the requirements of CVWD and IID. All parcels meet CVWD requirements including the region, elevation, minimum size, distance from the site, and proximity to one another. The metrics of these facilities will be provided by CVWD and the environmental impacts of the sites will be analyzed using secondary sources such as California Historical DRAFT 4.0 INFRASTRUCTURE PLAN TRAVERTINE SPECIFIC PLAN AMENDMENT – 2019 Page 4-6 Resources Information System (CHRIS) records search. Desktop analyses of biological, cultural and paleo will be performed on the proposed sites. The five-acre site required by IID for a substation will be studied with metrics provided by the utility. The location of the 5-acre site will be within a 2-mile radius of the project. The routing of the proposed service lines along the route to the site will be studied for visual impacts and aesthetics in addition to all other known impact metrics that IID will make available. Telephone service will be provided by Frontier or Spectrum. The applicant will comply with the requirements of all utilities. All existing and proposed utilities within or immediately adjacent to the proposed development shall be installed underground. Power lines with voltage higher than 35kV are exempt from this requirement. 4.6 Public Facilities & Services 4.6.1 Solid Waste Services associated with the collection and disposal of solid waste generated within the Travertine community will be operated and administered by Burrtec per the contract with the City of La Quinta. Individual developments within Travertine will implement measures that will be consistent with City regulations designed to reduce solid wastes, including but not limited to AB 939. 4.6.2 Fire Protection Fire protection service is provided for the City of La Quinta and administered by the Riverside County Fire Department. Presently, the Fire Department occupies three fire stations within the City: Station No. 32 located on 52nd Street west of Washington Street; Station No. 70 located at the intersection of Madison Street and Avenue 54; and Station No. 93 located on Adams Street north of Miles Avenue. Currently there is an ongoing discussion with Riverside County Fire Department and the City, to locate and fund the new south La Quinta fire station. At such time the location of the future fire station is determined, the interested parties will join in a “fair share” program to fund its installment. Emergency medical paramedic services are currently provided to the City by American Medical Response, a private paramedic ambulance agency. All water mains and fire hydrants providing the required fire flows will be constructed in accordance with the City Fire Code in effect at the time of development. In addition, the level of service required for Travertine will be aligned with the criteria for Category II - Urban as outlined in the Fire Protection Master Plan as follows: • Fire station located within three miles • Receipt of full "first alarmed" assignment within 15 minutes 4.6.3 Police Protection Law enforcement services are provided to the project site by the City of La Quinta Police Department through a service contract with the Riverside County Sheriff’s Department. The La Quinta Police Department will provide service to the project site from existing facilities located at City Hall DRAFT 4.0 INFRASTRUCTURE PLAN TRAVERTINE SPECIFIC PLAN AMENDMENT – 2019 Page 4-7 in the City of La Quinta. The current service agreement between the City and the Sheriff’s Department provides protection on a 24-hour basis, seven days per week. The Sheriff’s Department utilizes seven patrol deputies which result in typical response times of five minutes throughout the City. 4.6.4 Community Services & Facilities A large public library is located on Calle Tampico and is operated by the Riverside County Library System to serve City of La Quinta residents and visitors. The City of La Quinta is served by two school districts; the Coachella Valley Unified School District (CVUSD) and the Desert Sands Unified School District (DSUSD). The majority of the site is located within the CVUSD area. A small portion on the eastern side of the project site is within DSUSD boundaries. No school sites are proposed within the Travertine project site. 4.6.5 Recreation The recreation plan will include a network of trails, including both on-street and off-street trails, which will provide pedestrian opportunities for both residents and visitors (see Exhibit 2 .3). Two small parking and staging areas will be provided along Jefferson Street where it enters and exits the project site in the North and East. These trailheads are intended to facilitate use of the trails. The off-street trails will account for approximately 2 acres. The private onsite, off-street trail system inside the gates provides users a system that connects the planning areas north and south of Jefferson Street. The applicant will meet the City Parks dedication requirements as set forth in Chapter 13.48, La Quinta Municipal Code and in compliance with the goals and policies of the La Quinta General Plan. Credit shall be granted for onsite parks against park fees. DRAFT