2553 The Corner - WQMP 03.02.2022Whitewater River Region WQMP
Project Specific
Preliminary Water Quality Management Plan
For: Coral Mountain Resort: The Corner
South of Avenue 58; West of Madison Street, in the City of La Quinta
DEVELOPMENT NO. SDP 2021-0001
Prepared for:
Meriwether Companies
2440 Junction Place, Suite 200
Boulder, CO 80301
Telephone: (303) 395-3150
Prepared By:
Jesus Herrera-Cortes, CPSWQ, QSD/QSP
Prepared Under the Direction of:
Scott A. Wieborg, PE,
MSA Consulting, Inc.
34200 Bob Hope Drive
Rancho Mirage, CA 92270
Telephone: (760) 320-9811
Fax No. (760) 323-7893
Original Date Prepared: March 2, 2022
Revision Date(s): N/A
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
OWNER'S CERTIFICATION
This project-specific Preliminary Water Quality Management Plan (M-WQMP) has been prepared for:
Meriwether Companies by MSA Consulting, Inc. for the project known as Coral Mountain
Resort: The Corner in the City of La Quinta.
This WQMP is intended to comply with the requirements of the City of La Quinta for Coral
Mountain Resort: The Corner, which includes the requirement for the preparation and
implementation of a project-specific WQMP.
The undersigned, while owning the property/project described in the preceding paragraph, shall be
responsible for the implementation of this WQMP and will ensure that this WQMP is amended as
appropriate to reflect up-to-date conditions on the site. This WQMP will be reviewed with the
facility operator, facility supervisors, employees, tenants, maintenance and service contractors, or
any other party (or parties) having responsibility for implementing portions of this WQMP. At least
one copy of this WQMP will be maintained at the project site or project office in perpetuity.
The undersigned is authorized to certify and to approve implementation of this WQMP. The undersigned
is aware that implementation of this WQMP is enforceable under City of La Quinta Water Quality
Ordinance 493 (La Quinta Municipal Code Municipal Code Section 8.70).
If the undersigned transfers its interest in the subject property/project, the undersigned shall notify
the successor in interest of its responsibility to implement this WQMP.
"I, the undersigned, certify under penalty of law that I am the owner of the property that is the subject
of this WQMP, and that the provisions of this WQMP have been reviewed and accepted and that the
WQMP will be transferred to future successors in interest."
ATTEST
Owner's Signature
Owner's Printed Name
Owner's Title/Position
Date
2440 Junction Place, Suite 200
Boulder, CO 80301
THIS FORM SHALL BE NOTARIZED BEFORE ACCEPTANCE OF THE
FINAL PROJECT SPECIFIC WQMP
Notary Signature
Printed Name
Title/Position
Date
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 i
Contents
SECTION PAGE
I. Project Description ...................................................................................................................... 1
II. Site Characterization ................................................................................................................... 5
III. Pollutants of Concern .................................................................................................................. 7
IV. Hydrologic Conditions of Concern ............................................................................................ 9
V. Best Management Practices ...................................................................................................... 10
V.1 SITE DESIGN BMP CONCEPTS, LID/SITE DESIGN AND TREATMENT CONTROL BMPS .... 10
V.1.A SITE DESIGN BMP CONCEPTS AND LID/SITE DESIGN BMPS ................................. 12
V.1.B TREATMENT CONTROL BMPS ................................................................................ 18
V.1.C MEASURABLE GOAL SUMMARY ............................................................................. 19
V.2 SOURCE CONTROL BMPS ................................................................................................. 21
V.3 EQUIVALENT TREATMENT CONTROL BMP ALTERNATIVES ............................................ 24
V.4 REGIONALLY-BASED BMPS ............................................................................................. 24
VI. Operation and Maintenance Responsibility for BMPs ......................................................... 25
VII. Funding ....................................................................................................................................... 28
TABLES
TABLE 1. POLLUTANT OF CONCERN SUMMARY 7
TABLE 2. BMP SELECTION MATRIX BASED UPON POLLUTANT OF CONCERN REMOVAL EFFICIENCY 11
TABLE 3. IMPLEMENTATION OF SITE DESIGN BMP CONCEPTS 13
TABLE 4. LID/SITE DESIGN BMPS MEETING THE LID/SITE DESIGN MEASURABLE GOAL 17
TABLE 5: TREATMENT CONTROL BMP SUMMARY 19
TABLE 6: MEASURABLE GOAL SUMMARY 20
TABLE 7. SOURCE CONTROL BMPS 21
APPENDICES
A. CONDITIONS OF APPROVAL
B. VICINITY MAP, WQMP SITE PLAN, AND RECEIVING WATERS MAP
C. SUPPORTING DETAIL RELATED TO HYDROLOGIC CONDITIONS OF CONCERN (IF APPLICABLE)
D. EDUCATIONAL MATERIALS
E. SOILS REPORT (IF APPLICABLE)
F. STRUCTURAL BMP AND/OR RETENTION FACILITY SIZING CALCULATIONS AND DESIGN DETAILS
G. AGREEMENTS – CC&RS, COVENANT AND AGREEMENTS, BMP MAINTENANCE AGREEMENTS AND/OR
OTHER MECHANISMS FOR ENSURING ONGOING OPERATION, MAINTENANCE, FUNDING AND
TRANSFER OF REQUIREMENTS FOR THIS PROJECT-SPECIFIC WQMP
H. PHASE 1 ENVIRONMENTAL SITE ASSESSMENT – SUMMARY OF SITE REMEDIATION CONDUCTED AND
USE RESTRICTIONS
I. PROJECT-SPECIFIC WQMP SUMMARY DATA FORM
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 1
I. Project Description
Project Owner: Meriwether Companies
2440 Junction Place, Suite 200
Boulder, CO 80301
WQMP Preparer: Under the Direct Supervision of Scott A. Wieborg, PE
MSA Consulting, Inc.
34200 Bob Hope Drive
Rancho Mirage, CA 92270
Telephone: (760) 323-7893
Fax No.: (760) 323-7893
Project Site Address: Southwest corner of Avenue 58 and Madison Street
in the City of La Quinta
Planning Area: City of La Quinta Specific Plan 03-067
Community Name: City of La Quinta
Development Name: Coral Mountain Resort: The Corner
APN Number(s): 766-070-014
Latitude & Longitude: 33.6267, -116.2518
Receiving Water: Coachella Valley Stormwater Channel
Hydrologic/WQMP Area: 7.8 Acres
Standard Industrial Classification (SIC) Code(s):
•5399: Miscellaneous General Merchandise Stores
Formation of Home Owners' Association (HOA)
or Property Owners Association (POA): Y N
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Coral Mountain Resort: The Corner
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Additional Permits/Approvals required for the Project:
AGENCY Permit required
State Department of Fish and Wildlife, Fish and Game
Code §1602 Streambed Alteration Agreement Y N
State Water Resources Control Board, Clean Water Act
(CWA) Section 401 Water Quality Certification Y N
US Army Corps of Engineers, CWA Section 404 permit Y N
US Fish and Wildlife, Endangered Species Act Section 7
biological opinion Y N
Statewide Construction General Permit Coverage Y N
Statewide Industrial General Permit Coverage Y N
Other:
City of La Quinta Grading Permit Y N
City of La Quinta Building Permit Y N
• The proposed project activity will not divert or obstruct the natural flow or change
the bed, channel, or bank of any stream, river or lake. Therefore, a State Department
of Fish and Game, 1601 Streambed Alteration Agreement is not required.
• The proposed project activity will not result in discharge into navigable waters or
other impacts; therefore, a Clean Water Act Section 401 Water Quality Certification
permit is not required.
• The proposed facility will not result in the discharge of dredged or fill materials into
the Waters of the United States. A Clean Water Act Section 404 Permit is not
required for this project.
• The proposed project site is not recognized as a habitat of an endangered species nor
does it form part of a Conservation Area under the Coachella Valley Multiple
Species Habitat Conservation Plan. A U.S. Fish and Wildlife, Endangered Species
Act Section 7 biological opinion is not required for this project.
• The proposed project is not industrial in nature. Therefore, coverage under the
General Permit for Storm Water Discharges Associated with Industrial Activities is
not required. This project will obtain coverage under the State Water Board NPDES
General Permit for Storm Water Discharges Associated with Construction and Land
Disturbance Activities.
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
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Project Introduction and Existing Conditions
The scope of this Preliminary WQMP applies to SDP 2021-0001, which is part of SP 2019-0003,
Amendment V to SP 03-067. The project site of 7.8 acres exhibits a relatively level terrain with
scattered vegetation coverage, located at the southwest corner of Avenue 58 and Madison Street
in the City of La Quinta. The site design level of detail is preliminary for entitlement purposes
and will be updated with the final engineering design.
Description of Proposed Improvements
The project involves three proposed commercial retail buildings with both indoor and covered
exterior spaces intended to accommodate retail, storage, restaurant, and convenience store uses
as allowed in the Specific Plan. The site plan also includes parking lot facilities and areas of
future potential buildings as allowed in the Specific Plan. Moreover, the site includes designated
open space areas for surface retention and small-scale farm production to serve the on-site
restaurants and stores.
Consistent with the preliminary hydrology report, the entire project site is treated as one drainage
management area with two distinct land use cover conditions: commercial and fallow. The
commercial land use cover is considered to be fully impervious with the proposed buildings,
paving, and hardscape. Future final design will take into account the landscaped areas and other
conditions that may reduce the impervious factor of this use. The second land use condition will
be fallow land with a dual purpose of providing retention and potential small-scale growing areas
to serve the site. The fallow land will be fully pervious but will be properly stabilized.
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Summary of Drainage Area Retention Capacity
DRAINAGE
AREA ID AREA IMPERVIOUS AREA
AND PERCENTAGE
WQMP STORMWATER
VOLUME (VBMP)
MINIMUM PROVIDED
RETENTION CAPACITY
A 7.8 AC. 5.7 AC. (73 %) 5,934 CF 78,605 CF
As proposed, runoff from the commercial impervious portion will be conveyed toward multiple
designated retention areas. Based on these conditions and using the Whitewater Watershed BMP
Design Volume Worksheet, the Design Storage Volume (Vbmp) for Drainage Area A (as a
whole) is 5,934 cubic feet. The combined retention basin capacity will be 78,605 cubic feet
(minimum) which is sufficient to contain the flood volume resulting from the controlling 100-
year storm, as well as the smaller Vbmp volume for water quality purposes. The Final WQMP
will provide additional information based on final engineering design.
Location of Activities:
The project does not have a specific area where heightened activities would warrant additional
site design, source control or treatment measures other than those identified for each drainage
area. Final WQMP documentation is expected to provide additional detail based on a final site
design and engineering.
Waste Generation:
The proposed project is expected to generate non-hazardous solid waste typical of most
commercial land uses. The project’s waste will be collected and managed by Burrtec Waste
Industries on a typical schedule. Pollution prevention, waste reduction, and recycling practices
will be implemented on-site.
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II. Site Characterization
Land Use Designation or Zoning: Existing General Plan and Zoning:
Specific Plan 03-067
Proposed General Plan & Zoning:
Specific Plan 03-067
Current Property Use: Vacant
Proposed Property Use: Commercial
Availability of Soils Report: Y N
Phase 1 Site Assessment: Y N
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Receiving Waters for Urban Runoff from Site
Receiving
Waters
EPA Approved 303(d) List
Impairments
Designated
Beneficial
Uses
Proximity to
RARE Beneficial
Use Designated
Receiving
Waters
Coachella
Valley
Stormwater
Channel
DDT (Dichlorodiphenyltrichloroethane),
Dieldrin, Indicator Bacteria, PCBs
(Polychlorinated Biphenyls), Toxaphene,
Toxicity, Nitrogen, ammonia (Total
Ammonia)
FRSH, REC I
c, REC II c,
WARM,
WILD, RARE
d
Approximately 7.1
miles
The preceding table is based on the 2014 and 2016 Integrated Report (Clean Water Act Section 303(d)
List/305(b) Report. All impairments listed for Coachella Valley Stormwater Channel are under Category 5, which
apply to water segments where standards are not met and a Total Maximum Daily Load (TMDL) is required, but not
yet completed. All pollutant sources for this segment are unknown.
Abbreviations:
I – Intermittent Beneficial Use
FRSH – Freshwater Replenishment
REC I – Water Contact Recreation
REC II – Non-Contact Water Recreation
WARM – Warm Freshwater Habitat
WILD – Wildlife Habitat
RARE – Preservation of Rare, Threatened, or Endangered Species
MUN – Municipal & Domestic Supply
AGR – Agricultural Supply
GWR – Groundwater Recharge
AQUA – Acuaculture
COLD – Cold Freshwater Habitat
POW – Hydropower Generation
a. Although it is not encouraged, children play in the water infrequently on the wildlife reserve
b. Section of perennial flow from approximately Indio to the Salton Sea.
c. Unauthorized use.
d. Rare, endangered, or threatened wildlife exists in or utilizes some of this waterway.
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Coral Mountain Resort: The Corner
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III. Pollutants of Concern
Table 1. Pollutant of Concern Summary
Pollutant Category
Potential for
Project
Causing Receiving
Water Impairment
Bacteria/Virus (Pathogens) Yes Yes (Pathogens)
Heavy Metals Yes No
Nutrients Yes No
Toxic Organic Compounds Yes No
Total Ammonia (Nitrogen, ammonia) No Yes
Toxicity No Yes
Sediment/Turbidity Yes No
Trash & Debris Yes No
Oil & Grease Yes No
The Coachella Valley Stormwater Channel is impaired by DDT (Dichlorodiphenyltrichloroethane),
Dieldrin, Indicator Bacteria, PCBs (Polychlorinated Biphenyls), Toxaphene, Toxicity and Total
Ammonia (Nitrogen, ammonia).
• The project is not anticipated to generate DDT contamination because the use of this substance
(synthetic organic compound) has been banned since 1972; therefore, it will not be handled or form
part of the proposed development.
• The project is not anticipated to generate Dieldrin contamination because the use of this substance
(synthetic organic compound) was related to agricultural operations (found in pesticides for crops)
and it has been illegal since 1987; therefore, it will not be handled or form part of the proposed
development.
• The project is not anticipated to produce polychlorinated biphenyls (PCBs) because manufacturing
this substance (synthetic organic compound) stopped in 1977 and its application was banned in 1979;
therefore, it will not be handled or form part of the proposed development.
• The proposed development is not anticipated to produce toxaphene because the use of this substance
(synthetic organic compound) has been illegal since 1990; therefore, it will not be handled or form
part of the proposed development.
• The proposed office development is not anticipated to produce Nitrogen, ammonia (Total Ammonia).
Ammonia is a nutrient typically associated with commercial fertilizers utilized in agricultural
operations. The project’s retention facilities will contain runoff, such that it will not reach the
impaired receiving waters.
• The project has the potential to generate small amounts of pathogens (bacteria/virus). These
pollutants are generally associated with various human activities, but pathogens are also present in
natural environments. Moreover, pathogens can be associated with wild and domesticated animal
waste. Source control measures to address this potential pollutant are discussed in the subsequent
sections of this report. Runoff from the project will be conveyed to proposed retention facilities sized
to capture and infiltrate the controlling 100-year storm event and the design capture volume for water
Whitewater River Region WQMP
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quality purposes (Vbmp). Therefore, no discharge of pathogens in runoff is expected as part of the
standard operating condition.
• The project is not expected to generate or discharge toxicants, such as toxic metals and synthetic
organic compounds that would result in detrimental physiological responses in human, plant, animal,
or indigenous aquatic life in the Coachella Valley Storm Water Channel. Due to the project’s location
and proposed improvements, the project will not involve direct or indirect discharges into the
Coachella Valley Storm Water Channel. All project runoff will be conveyed to on-site retention
facilities.
Table 1 (Potential Pollutants Generated by Land Use Type) of the Riverside County Whitewater
River Region Stormwater Quality Best Management Practice Design Handbook for Low Impact
Development identifies eight (8) land use categories with their corresponding potential pollutants that
may be generated. The land uses pertaining to this project and allowed under the Specific Plan are
listed below.
Type of
Development
(Land Use)
Sediment/
Turbidity
Nutrients Toxic
Organic
Compounds
Trash
& Debris
Bacteria &
Viruses
(Also:
Pathogens)
Oil
&
Grease
Heavy
Metals
Restaurants N N N P P P N
Parking Lots P P(1) P(4) P P P P
Commercial Development P P(1) P(5) P P(3) P P(6)
Abbreviations:
P = Potential N = Not potential
Notes:
(1) A potential Pollutant if non-native landscaping exists or is proposed onsite; otherwise not expected.
(2) A potential Pollutant if the project includes uncovered parking areas; otherwise not expected.
(3) A potential Pollutant if land use involves food or animal waste products.
(4) Specifically, petroleum hydrocarbons.
(5) Specifically, solvents; however, this Pollutant is not expected at commercial office or commercial retail sites, unless said retail is vehicle
related.
(6) A potential Pollutant if the project includes outdoor storage or metal roofs; otherwise not expected.
Potential Project Pollutants: The project’s land uses have the generalized potential to produce
sediment/turbidity; nutrients; toxic organic compounds; trash and debris; bacteria and viruses
(including pathogens); oil and grease; and heavy metals.
Legacy Pollutants: There is no evidence or other known information of legacy pollutants on-site.
Pollutants of Concern: Based on the comparison of potential project pollutants with the pollutant
categories causing receiving water impairments, the pollutants of concern include bacteria/virus.
The project’s proposed storm drain improvements are designed to intercept and retain the flood
volume resulting from the 100-year storm event. Therefore, the project will not produce pollutants
that could affect off-site or downstream resources, such as the proximate receiving waters.
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 9
IV. Hydrologic Conditions of Concern
Local Jurisdiction Requires On-Site Retention of Urban Runoff:
Yes The project will be required to retain urban runoff onsite in conformance with local ordinance
(See Table 6 of the WQMP Guidance document, "Local Land use Authorities Requiring
Onsite Retention of Stormwater"). This section does not need to be completed; however,
retention facility design details and sizing calculations must be included in Appendix F.
Note: The Preliminary WQMP and Preliminary Hydrology Report for this project have
identified retention areas with a combined capacity for the flood volume resulting from
the 100-year controlling storm event. The precise grading, hydrology and facility details
will be provided in the Final WQMP, Final Hydrology Report and Precise Grading
Plans. As a result, the project will not result in changes to the hydrologic regime that
will permanently impact downstream channels, receiving waters, or habitat integrity.
No Hydrologic Conditions of Concern are expected to result from the project. The local
jurisdiction requirements for on-site retention of urban runoff will be met.
No This section must be completed.
This Project meets the following condition:
Condition A: 1) Runoff from the Project is discharged directly to a publicly-owned,
operated and maintained MS4 or engineered and maintained channel, 2) the discharge is in
full compliance with local land use authority requirements for connections and discharges to
the MS4 (including both quality and quantity requirements), 3) the discharge would not
significantly impact stream habitat in proximate Receiving Waters, and 4) the discharge is
authorized by the local land use authority.
Condition B: The project disturbs less than 1 acre and is not part of a larger common plan
of development that exceeds 1 acre of disturbance. The disturbed area calculation must
include all disturbances associated with larger plans of development.
Condition C: The project's runoff flow rate, volume, velocity and duration for the post-
development condition do not exceed the pre-development condition for the 2-year, 24-hour
and 10-year 24-hour rainfall events. This condition can be achieved by, where applicable,
complying with the local land use authority's on-site retention ordinance, or minimizing
impervious area on a site and incorporating other Site-Design BMP concepts and LID/Site
Design BMPs that assure non-exceedance of pre-development conditions. This condition
must be substantiated by hydrologic modeling methods acceptable to the local land use
authority.
None: Refer to Section 3.4 of the Whitewater River Region WQMP Guidance document for
additional requirements.
Supporting engineering studies, calculations, and reports are included in Appendix C.
Whitewater River Region WQMP
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March 2, 2022 10
V. Best Management Practices
This project implements Best Management Practices (BMPs) to address the Pollutants of
Concern that may potentially be generated from the use of the project site. These BMPs have
been selected and implemented to comply with Section 3.5 of the WQMP Guidance document,
and consist of Site Design BMP concepts, Source Control, LID/Site Design and, if/where
necessary, Treatment Control BMPs as described herein.
V.1 SITE DESIGN BMP CONCEPTS, LID/SITE DESIGN AND TREATMENT
CONTROL BMPS
Local Jurisdiction Requires On-Site Retention of Urban Runoff:
Yes The project will be required to retain Urban Runoff onsite in conformance with local
ordinance (See Table 6 of the WQMP Guidance document, "Local Land use Authorities
Requiring Onsite Retention of Stormwater). The LID/Site Design measurable goal has
thus been met (100%), and Sections V.1.A and V.1.B do not need to be completed;
however, retention facility design details and sizing calculations must be included in
Appendix F, and '100%' should be entered into Column 3 of Table 6 below.
Note: The Preliminary WQMP and Preliminary Hydrology Report for this project have
identified retention areas with a combined capacity for the flood volume resulting from
the 100-year controlling storm event. The precise grading, hydrology and facility details
will be provided in the Final WQMP, Final Hydrology Report and Precise Grading
Plans. As a result, the project will not result in changes to the hydrologic regime that
will permanently impact downstream channels, receiving waters, or habitat integrity.
No Hydrologic Conditions of Concern are expected to result from the project. The local
jurisdiction requirements for on-site retention of urban runoff will be met.
No Section V.1 must be completed.
This section of the Project-Specific WQMP documents the LID/Site Design BMPs and, if/where
necessary, the Treatment Control BMPs that will be implemented on the project to meet the requirements
detailed within Section 3.5.1 of the WQMP Guidance document. Section 3.5.1 includes requirements to
implement Site Design Concepts and BMPs, and includes requirements to address Pollutants of Concern
with BMPs. Further, sub-section 3.5.1.1 specifically requires that Pollutants of Concern be addressed with
LID/Site Design BMPs to the extent feasible.
LID/Site Design BMPs are those BMPs listed within Table 2 below which promote retention and/or
feature a natural treatment mechanism; off-site and regionally-based BMPs are also LID/Site Design
BMPs, and therefore count towards the measurable goal, if they fit these criteria. This project
incorporates LID/Site Design BMPs to fully address the Treatment Control BMP requirement where and
to the extent feasible. If and where it has been acceptably demonstrated to the local land use authority that
it is infeasible to fully meet this requirement with LID/Site Design BMPs, Section V.1.B (below) includes
a description of the conventional Treatment Control BMPs that will be substituted to meet the same
requirements. In addressing Pollutants of Concern, BMPs are selected using Table 2 below.
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Table 2. BMP Selection Matrix Based Upon Pollutant of Concern Removal Efficiency (1)
(Sources: Riverside County Flood Control & Water Conservation District Design Handbook for Low Impact Development Best Management Practices, dated September 2011, the
Orange County Technical Guidance Document for Water Quality Management Plans, dated May 19, 2011, and the Caltrans Treatment BMP Technology Report, dated April 2010
and April 2008)
Pollutant of
Concern Landscape Swale2, 3 Landscape Strip2, 3 Biofiltration (with underdrain)2, 3 Extended Detention Basin2 Sand Filter Basin2 Infiltration Basin2 Infiltration Trench2 Permeable Pavement2 Bioretention (w/o underdrain)2, 3 Other BMPs Including Proprietary BMPs4, 6 Sediment &
Turbidity M M H M H H H H H Varies by Product5 Nutrients L/M L/M M L/M L/M H H H H
Toxic Organic
Compounds M/H M/H M/H L L/M H H H H
Trash & Debris L L H H H H H L H
Bacteria & Viruses
(also: Pathogens) L M H L M H H H H
Oil & Grease M M H M H H H H H
Heavy Metals M M/H M/H L/M M H H H H
Abbreviations:
L: Low removal efficiency M: Medium removal efficiency H: High removal efficiency
Notes:
(1) Periodic performance assessment and updating of the guidance provided by this table may be necessary.
(2) Expected performance when designed in accordance with the most current edition of the document, "Riverside
County, Whitewater River Region Stormwater Quality Best Management Practice Design Handbook".
(3) Performance dependent upon design which includes implementation of thick vegetative cover. Local water
conservation and/or landscaping requirements should be considered; approval is based on the discretion of the
local land use authority.
(4) Includes proprietary stormwater treatment devices as listed in the CASQA Stormwater Best Management Practices
Handbooks, other stormwater treatment BMPs not specifically listed in this WQMP (including proprietary filters,
hydrodynamic separators, inserts, etc.), or newly developed/emerging stormwater treatment technologies.
(5) Expected performance should be based on evaluation of unit processes provided by BMP and available testing
data. Approval is based on the discretion of the local land use authority.
(6) When used for primary treatment as opposed to pre-treatment, requires site-specific approval by the local land use
authority.
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V.1.A SITE DESIGN BMP CONCEPTS AND LID/SITE DESIGN BMPS
Note: This section is not applicable Due to conformance with local retention ordinance per
Section 3.5.1.2 of Whitewater River Region WQMP Guidance Document.
This section documents the Site Design BMP concepts and LID/Site Design BMPs that will be
implemented on this project to comply with the requirements detailed in Section 3.5.1 of the
WQMP Guidance document.
• Table 3 herein documents the implementation of the Site Design BMP Concepts
described in sub-sections 3.5.1.3 and 3.5.1.4.
• Table 4 herein documents the extent to which this project has implemented the LID/Site
Design goals described in sub-section 3.5.1.1.
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Table 3. Implementation of Site Design BMP Concepts
Note: Completion of this sub-section is not required since the project retains urban runoff on-site in conformance with the local ordinances.
Included
Brief Reason for BMPs
Indicated as No or N/A Design
Concept Technique Specific BMP Yes No N/A Site Design BMP Concept 1 Minimize Urban
Runoff,
Minimize
Impervious
Footprint, and
Conserve
Natural Areas
(See WQMP
Section 3.5.1.3)
Conserve natural areas by concentrating or clustering development on
the least environmentally sensitive portions of a site while leaving the
remaining land in a natural, undisturbed condition.
Conserve natural areas by incorporating the goals of the Multi-Species
Habitat Conservation Plan or other natural resource plans.
Preserve natural drainage features and natural depressional storage
areas on the site.
Maximize canopy interception and water conservation by preserving
existing native trees and shrubs, and planting additional native or
drought tolerant trees and large shrubs.
Use natural drainage systems.
Where applicable, incorporate Self-Treating Areas
Where applicable, incorporate Self-Retaining Areas
Increase the building floor to area ratio (i.e., number of stories above or
below ground).
Construct streets, sidewalks and parking lot aisles to minimum widths
necessary, provided that public safety and a walkable environment for
pedestrians are not compromised.
Reduce widths of streets where off-street parking is available.
Minimize the use of impervious surfaces, such as decorative concrete, in
the landscape design.
Other comparable and equally effective Site Design BMP concept(s) as
approved by the local land use authority (Note: Additional narrative
required to describe BMP and how it addresses site design concept).
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Table 3. Site Design BMP Concepts (continued)
Note: Completion of this sub-section is not required since the project retains urban runoff on-site in conformance with the local ordinances.
Included
Brief Reason for Each BMP
Indicated as No or N/A Design
Concept Technique Specific BMP Yes No N/A Site Design BMP Concept 2 Minimize
Directly
Connected
Impervious
Area
(See WQMP
Section
3.5.1.4)
Design residential and commercial sites to contain and infiltrate roof runoff, or
direct roof runoff to landscaped swales or buffer areas.
Drain impervious sidewalks, walkways, trails, and patios into adjacent
landscaping.
Incorporate landscaped buffer areas between sidewalks and streets.
Use natural or landscaped drainage swales in lieu of underground piping or
imperviously lined swales.
Where soil conditions are suitable, use perforated pipe or gravel filtration pits
for low flow infiltration.
Maximize the permeable area by constructing walkways, trails, patios,
overflow parking, alleys, driveways, low-traffic streets, and other low-traffic
areas with open-jointed paving materials or permeable surfaces such as
pervious concrete, porous asphalt, unit pavers, and granular materials.
Use one or more of the following:
Rural swale system: street sheet flows to landscaped swale or gravel
shoulder, curbs used at street corners, and culverts used under driveways and
street crossings.
Urban curb/swale system: street slopes to curb; periodic swale inlets drain to
landscaped swale or biofilter.
Dual drainage system: first flush captured in street catch basins and
discharged to adjacent vegetated swale or gravel shoulder; high flows connect
directly to MS4s.
Other comparable and equally effective Site Design BMP concept(s) as
approved by the local land use authority (Note: Additional narrative required to
describe BMP and how it addresses site design concept).
Use one or more of the following for design of driveways and private residential parking areas:
Design driveways with shared access, flared (single lane at street), or wheel
strips (paving only under the tires).
Uncovered temporary or guest parking on residential lots paved with a
permeable surface, or designed to drain into landscaping.
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 15
Table 3. Site Design BMP Concepts (continued)
Note: Completion of this sub-section is not required since the project retains urban runoff on-site in conformance with the local ordinances.
Included
Brief Reason for Each BMP
Indicated as No or N/A Design
Concept Technique Specific BMP Yes No N/A Site Design BMP Concept 2 (cont'd)
Minimize
Directly
Connected
Impervious
Area
(See WQMP
Section
3.5.1.4)
Other comparable and equally effective Site Design BMP concept(s) as
approved by the local land use authority (Note: Additional narrative required to
describe BMP and how it addresses site design concept).
Use one or more of the following for design of parking areas:
Where landscaping is proposed in parking areas, incorporate parking area
landscaping into the drainage design.
Overflow parking (parking stalls provided in excess of the Permittee's
minimum parking requirements) may be constructed with permeable
pavement.
Other comparable and equally effective Site Design BMP (or BMPs) as
approved by the local land use authority (Note: Additional narrative required
describing BMP and how it addresses site design concept).
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 16
Project Site Design BMP Concepts:
Note: This section is not applicable Due to conformance with local retention ordinance per
Section 3.5.1.2 of Whitewater River Region WQMP Guidance Document.
Alternative Project Site Design BMP Concepts:
Not Applicable
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 17
Table 4. LID/Site Design BMPs Meeting the LID/Site Design Measurable Goal
(1) (2) (3) (4) (5) (6) (7)
DRAINAGE SUB-AREA ID OR NO.
LID/SITE DESIGN BMP TYPE* POTENTIAL POLLUTANTS OF CONCERN WITHIN
DRAINAGE SUB-AREA
POTENTIAL POLLUTANTS WITHIN SUB-AREA CAUSING RECEIVING
WATER IMPAIRMENTS
EFFECTIVENESS OF LID/SITE DESIGN BMP AT ADDRESSING IDENTIFIED POTENTIAL
POLLUTANTS
BMP MEETS WHICH DESIGN
CRITERIA?
TOTAL AREA WITHIN DRAINAGE SUB-
AREA
(See Table 2) (Refer to Table 1) (Refer to Table 1) (U, L, M, H/M, H; see Table 2) (Identify as VBMP OR QBMP) (Nearest 0.1 acre)
Area A Infiltration BMP
(Retention Basin) Bacteria/virus Bacteria/virus H
5,934 CU. FT. (VBMP)
Minimum Retention Capacity Provided: 78,605 CU. FT.
7.8
TOTAL PROJECT AREA TREATED WITH LID/SITE DESIGN BMPs (NEAREST 0.1 ACRE) 7.8
* LID/Site Design BMPs listed in this table are those that completely address the 'Treatment Control BMP requirement' for their
drainage sub-area.
Note: This Preliminary WQMP covers drainage areas A through E. The development of drainage areas F through I will be covered by a
separate WQMP based on a corresponding future site design. Conformance with the local retention requirements will be satisfied by
conveying project runoff into proposed on-site retention facilities.
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 18
Justification of infeasibility for sub-areas not addressed with LID/Site Design BMPs
Not applicable.
V.1.B TREATMENT CONTROL BMPS
Conventional Treatment Control BMPs shall be implemented to address the project's Pollutants
of Concern as required in WQMP Section 3.5.1 where, and to the extent that, Section V.1.A has
demonstrated that it is infeasible to meet these requirements through implementation of LID/Site
Design BMPs.
The LID/Site Design BMPs described in Section V.1.A of this project-specific WQMP
completely address the 'Treatment Control BMP requirement' for the entire project site
(and where applicable, entire existing site) as required in Section 3.5.1.1 of the WQMP
Guidance document. Supporting documentation for the sizing of these LID/Site Design
BMPs is included in Appendix F. *Section V.1.B does not need to be completed.
Note: The project includes a system of on-site retention basins sized to
retain/infiltrate the volume resulting from the 100-year controlling storm event. As
such, the proposed on-site retention capacity will also be sufficient to handled the
corresponding Vbmp volume for water quality purposes.
The LID/Site Design BMPs described in Section V.1.A of this project-specific WQMP
do NOT completely address the 'Treatment Control BMP requirement' for the entire
project site (or where applicable, entire existing site) as required in Section 3.5.1.1 of the
WQMP. *Section V.1.B must be completed.
The Treatment Control BMPs identified in this section are selected, sized and implemented to
treat the design criteria of VBMP and/or QBMP for all project (and if required, existing site)
drainage sub-areas which were not fully addressed using LID/Site Design BMPs. Supporting
documentation for the sizing of these Treatment Control BMPs is included in Appendix F.
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 19
Table 5: Treatment Control BMP Summary
(1) (2) (3) (4) (5) (6) (7)
DRAINAGE
SUB-AREA
ID OR NO.
TREATMENT
CONTROL BMP
TYPE*
POTENTIAL
POLLUTANTS OF
CONCERN WITHIN
DRAINAGE SUB-AREA
POTENTIAL
POLLUTANTS
WITHIN SUB-AREA
CAUSING
RECEIVING
WATER
IMPAIRMENTS
EFFECTIVENESS OF
TREATMENT
CONTROL BMP AT
ADDRESSING
IDENTIFIED
POTENTIAL
POLLUTANTS
BMP MEETS
WHICH
DESIGN
CRITERIA?
TOTAL
AREA
WITHIN
DRAINAGE
SUB-AREA
(See Table 2) (Refer to Table 1) (Refer to Table 1) (U, L, M, H/M, H; see Table
2) (Identify as
VBMP OR QBMP) (Nearest 0.1
acre)
N/A N/A N/A N/A N/A N/A N/A
TOTAL PROJECT AREA TREATED WITH TREATMENT CONTROL BMPs (NEAREST 0.1 ACRE) N/A
Note: Conformance with the local retention requirements will be satisfied by conveying project runoff into proposed on-site retention
facilities.
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 20
V.1.C MEASURABLE GOAL SUMMARY
This section documents the extent to which this project has met the measurable goal described in
WQMP Section 3.5.1.1 of addressing 100% of the project's 'Treatment Control BMP
requirement' with LID/Site Design BMPs. Projects required to retain Urban Runoff onsite in
conformance with local ordinance are considered to have met the measurable goal; for these
instances, '100%' is entered into Column 3 of the Table.
Table 6: Measurable Goal Summary
(1) (2) (3)
Total Area Treated with
LID/Site Design BMPs
Total Area Treated with
Treatment Control BMPs % of Treatment Control BMP
Requirement addressed with
LID/Site Design BMPs (Last row of Table 4) (Last row of Table 5)
7.8
N/A
Due to conformance with local
retention ordinance per Section
3.5.1.2 of Whitewater River
Region WQMP Guidance
Document.
100
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 21
V.2 SOURCE CONTROL BMPS
This section identifies and describes the Source Control BMPs applicable and implemented on
this project.
Table 7. Source Control BMPs
BMP Name
Check One If not applicable, state
brief reason Included Not
Applicable
Non-Structural Source Control BMPs
Education for Property Owners, Operators,
Tenants, Occupants, or Employees
Activity Restrictions
Irrigation System and Landscape Maintenance
Common Area Litter Control
Street Sweeping Private Streets and Parking Lots
Drainage Facility Inspection and Maintenance
Structural Source Control BMPs
Storm Drain Inlet Stenciling and Signage
Landscape and Irrigation System Design
Protect Slopes and Channels
Provide Community Car Wash Racks Not part of the proposed project.
Properly Design*:
Fueling Areas
Air/Water Supply Area Drainage
Trash Storage Areas
Loading Docks Not part of the proposed project.
Maintenance Bays Not part of the proposed project.
Vehicle and Equipment Wash Areas Not part of the proposed project.
Outdoor Material Storage Areas Not part of the proposed project.
Outdoor Work Areas or Processing Areas Not part of the proposed project.
Provide Wash Water Controls for Food
Preparation Areas
Pursuant to Section E.4.b.v of
the Whitewater River Region
MS4, discharges from food-
related wastes into the storm
drain system or MS4 are
prohibited.
*Details demonstrating proper design must be included in Appendix F.
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 22
Non-Structural Source Control BMPs
Education Program: (Property management/operator)
Employees and maintenance staff should be informed on topics related to stormwater pollution
and prevention through various means, which can include the distribution of printed materials or
public posting of rules or activity restrictions. A series of guidelines should be formulated and
promoted to communicate beneficial habits and restricting activities which could impact the
storm drain system. Appendix D includes samples of the educational materials that can be used
in implementing this project-specific WQMP.
Activity Restrictions: (Property management/operator)
The following activities should be prevented or prohibited on-site: littering; discharge and waste
dumping into parking storm drain inlets; blowing, sweeping or hosing of debris into streets or
parking lots; nuisance water flows from irrigation.
Irrigation System and Landscape Maintenance: (Property management/operator)
Operation and Maintenance responsibilities and scheduling should be adhered to throughout the
life of the project. The irrigation and landscape maintenance will help increase the effectiveness
of these systems and minimize the amount of runoff that enters the storm drain system. Erosion
and the conveyance of pesticides/fertilizers in runoff should also be prevented through proper
routine maintenance. Routine irrigation system and landscape maintenance will also serve as a
vector control measure due to the minimization of nuisance water runoff and stagnation.
Common Area Litter Control: (Property management/operator)
Common area litter control should be implemented to reduce pollution in runoff. Routine or
scheduled monitoring should be performed in the common areas, landscaped areas, parking lots,
in and around the trash enclosures, and along the perimeter walls of the project. Any observed
accumulated trash, vegetation debris or improper disposal should be addressed promptly by the
designated staff. Common area litter control measures can be coordinated and improved by the
landscaping maintenance that will take place at the site. The raking or sweeping of trash shall
only be performed in manner that avoids trash from entering the storm drain system. All
landscape-related debris or maintenance deficiencies are to be corrected promptly.
Paved Area Sweeping and Cleaning: (Property management/operator)
Paved area sweeping and cleaning should be performed on-site on a routine basis to prevent
trash, sediment, and other debris from being conveyed into the on-site storm drain system. Paved
area sweeping should be performed during dry weather and the frequency should be flexible to
accommodate climate conditions and areas of concern. Street sweeping equipment must be
operated only by trained personnel based on the manufacturer’s specifications. Street sweeping
equipment should be properly maintained off-site by the operator. All collected debris must be
taken to an approved permanent disposal site.
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 23
Structural Source Control BMPs
The project will incorporate measures to discourage illegal dumping in the proposed private
storm drain system.
• MS4 Stenciling: (Property management/operator)
At each storm drain inlet, a stencil or fixed sign (including medallions) should contain a
brief statement that prohibits dumping of improper materials into the urban runoff
conveyance system. The legibility of markers and signs should be maintained throughout
the life of the project.
• Rules and Regulations: (Property management/operator)
The management should establish and implement rules that prohibit improper non-
stormwater discharge into the storm drain system. This measure may also be considered
non-structural and form part of the activity restrictions associated with the site’s standard
operating procedures.
• Signage at the Trash Enclosures: (Property management/operator)
Language prohibiting illegal dumping into the storm drain system should be integrated in
the signage posted on the side of trash enclosures with the intent to discourage trash and
waste misplacement that could ultimately impact the on-site storm drain system.
Landscape and Irrigation System Design: (Property management/operator)
The site’s structural source control BMP involves an efficient landscape irrigation design. The
system will include native or drought-tolerant plants and mechanisms to minimize excess
irrigation and nuisance water into the stormwater conveyance system while working to reduce
soil amendments and irrigation frequency. The system should also minimize the conveyance of
landscape related chemicals, including pesticides.
Trash Containers: (Property management/operator)
Trash containers shall be leak proof and have attached covers or lids. Connection of trash to the
MS4 shall be prohibited.
Storm Drain System Facilities: (Property management/operator)
Storm drain inlets and storm drainage facilities on-site should be inspected, cleaned, and
maintained routinely. Maintenance staff should take prompt action to correct or repair
malfunctioning facilities.
Safer Alternative Products (CASQA SC-35): (Property management/operator)
The use of less harmful products as alternatives to chemical fertilizers, pesticides, cleaning
solutions, janitorial chemicals, and consumables will be pursued under the guidance of SC-35
primarily aimed at the commercial portions of the project. The objective of this Source Control
BMP will be to integrate the measures as much as possible with the future programs at this
facility.
Building and Grounds Maintenance (CASQA SC-41): (Property management/operator)
A series of maintenance practices can be implemented to prevent or reduce the discharge of
potential pollutants into the storm drain system resulting from building and grounds maintenance
activities. The BMP implementation will be achieved with the following guidelines under SC-41:
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 24
washing and cleaning up with as little water as possible; following good landscape management
practices; preventing and cleaning up spills immediately; keeping debris from entering the storm
drains; and properly maintaining the stormwater collection system.
Protection of Slopes and Channels: (Property management/operator)
Landscaping improvements will help stabilize the proposed landscaped areas and prevent
erosion. These areas will be subject to routine maintenance to address potential instances of soil
erosion. Basin slopes should be visually inspected on a quarterly basis and after major rainfall
events. Physical obstructions caused by vegetation debris or littering should be cleared to ensure
that the slopes continue to function as designed. Any material collected (e.g. landscape debris or
trash) should be properly handled and disposed of.
Note about Wash Water Controls for Food Preparation Areas: Pursuant to Section E.4.b.v of
the Whitewater River Region MS4, illicit discharges to the MS4 of food-related wastes (e.g.
grease, fish processing, and restaurant kitchen mat and trash bin water, etc.) are prohibited. Food
preparation areas (per State Health & Safety Code 27520) shall have either contained areas or
sinks, each with connections to the sanitary sewer for disposal of wash waters containing kitchen
and food wastes. The entry of wash water controls into urban runoff or the proposed storm drain
system is prohibited.
V.3 EQUIVALENT TREATMENT CONTROL BMP ALTERNATIVES
Not applicable.
V.4 REGIONALLY-BASED BMPS
Not Applicable
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 25
VI. Operation and Maintenance Responsibility for
BMPs
The WQMP shall include the applicable copies of the mechanisms used to ensure the ongoing operation,
maintenance, funding, transfer and implementation of the project-specific WQMP requirements.
TABLE 8 -OPERATIONS AND MAINTENANCE
BMP Requiring
Maintenance
Party
Responsibility
Recommended
Inspection and
Maintenance
Frequency
Recommended
Self-Inspection and
Record Keeping
Implementation Period Recommended
O & M
Activities and
Process
Landscaped Areas
Property Owner,
Operator, Hired
Management,
Home Owner’s
Association
At least twice
monthly or according
to a maintenance
schedule.
Quarterly summaries of
inspection and maintenance
activities should be
appended to the WQMP.
Post-Construction
(See the following
page)
Irrigation System
Property Owner,
Operator, Hired
Management,
Home Owner’s
Association
At least twice
monthly or according
to a maintenance
schedule.
Trash Enclosures
and Common Area
Litter Control
Property Owner,
Operator, Hired
Management,
Home Owner’s
Association
Based on trash pick-
up intervals and
according to a
maintenance
schedule.
Paved Area
Sweeping
Property Owner,
Operator, Hired
Management,
Home Owner’s
Association
Twice monthly or
according to a
maintenance
schedule
Storm Drain System
Property Owner,
Operator, Hired
Management,
Home Owner’s
Association
Quarterly and
after storm events or
according to a
maintenance
schedule
Retention Basins
Property Owner,
Operator, Hired
Management,
Home Owner’s
Association
Quarterly and
after storm events or
according to an
established
maintenance
schedule
*Note: “Storm events” refer to precipitation events producing 0.5 inches of rain or greater within a 48-hour period. The occurrence of these
events may be confirmed against the local rain event summaries published in the National Weather Service or National Oceanic and
Atmospheric Administration web site (www.noaa.gov). The recommended inspection, maintenance, and recordkeeping practices in this
WQMP may be addressed by a formal schedule, operations manual, and other standard operating procedures which may be developed for
this site.
Note: The maintenance recommendations, including responsible parties, inspection intervals, and
maintenance intervals, and activities are not intended to be exhaustive in nature and should not
serve as the sole source of on-site operating procedures. As the Final WQMP documentation is
produced for City review and approval, additional maintenance procedures may be necessary to
implement. Where applicable, refer to the equipment manufacturer’s recommendations.
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 26
Description of Maintenance Requirements:
Landscaped Areas: All trimming, pruning, and removal of fallen organic material from plants,
shrubs, and trees should be collected per an approved or adopted landscape maintenance plan,
stored in an appropriate location and transported to an approved green-waste collection facility.
Any equipment or material temporarily staged during maintenance activities should be placed
away from drainage courses and storm drain inlets. Contracted maintenance staff should haul
collected material promptly following the maintenance activities to avoid prolonged on-site
storage. The planting materials are to remain as indicated on the approved set of landscape
planting plans. In conjunction with the routine activities, maintenance staff should verify that the
landscape design continues to function properly by adjusting to eliminate overspray to hardscape
areas and to verify that irrigation timing and cycle lengths are adjusted in accordance with water
demands, given the time of year, weather and day or nighttime temperatures.
Irrigation Systems: Water conservation is to be maintained at all times per the approved
irrigation plans. Monitoring of the irrigation system should be provided as necessary to ensure
that appropriate watering levels are maintained and to verify that no piping or irrigation heads
are leaking. Any debris, sediment, mineral and grit deposits should be removed from the
irrigation system at regular intervals to provide consistent watering levels.
The irrigation and landscape maintenance will help increase the effectiveness of these systems
and minimize the amount of runoff that enters the storm drain system. Erosion and the
conveyance of pesticides/fertilizers in runoff will also be prevented through routine maintenance.
Routine irrigation system and landscape maintenance will also serve as a vector control measure
due to the minimization of nuisance water runoff and stagnation.
Trash Management and Common Area Litter Control: Common area litter control should be
implemented to reduce pollution in runoff. Routine or scheduled monitoring should be
performed in the common areas, landscaped areas, parking lots, in and around the trash
enclosures, and along the perimeter walls of the project. Any observed accumulated trash,
vegetation debris or improper disposal should be addressed promptly by the designated staff.
Common area litter control measures can be coordinated and improved by the landscaping
maintenance that will take place at the site. All landscape-related debris or maintenance
deficiencies are to be corrected immediately. No trash should be allowed to be stored at the base
of the containers. Pick-up intervals are to be determined so that the containers are not overfilled.
Only approved materials and chemicals should be allowed in the dumpsters.
Storm Drain System: Storm water conveyance systems, including inlets, outlets, cleanouts,
manholes and pipelines within the project are to be inspected quarterly and after each major
storm event or according to a maintenance schedule. All parts of the system are to be
periodically cleaned to ensure that the system works properly during any storm event. Any waste
collected from the cleaning activities is to be stored and properly disposed of.
Paved Area Sweeping and Cleaning
Paved area sweeping and cleaning should be performed on-site, specifically in the parking areas,
to prevent sediment, litter and other debris from being washed by runoff into the on-site storm
drain system. Paved area sweeping should be performed during dry weather if possible and the
frequency should be flexible to accommodate climate conditions and areas of concern. Street
sweeping equipment must be operated only by trained personnel based on the manufacturer’s
specifications. Street sweeping equipment should be properly maintained off-site by the operator.
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 27
Sweeping equipment should not be maintained or washed off on-site. All collected debris must
be taken to an approved permanent disposal site.
Retention Basins: Retention basins should be visually inspected on a quarterly basis or
according to a landscaping maintenance schedule. Physical obstructions caused by vegetation
debris or littering should be promptly cleared to ensure that the basins continue to function as
designed. Any material collected (e.g. landscape debris or trash) should be properly handled and
disposed of. Basin outlets must be inspected for signs of erosion or obstruction. The condition
and effectiveness of the basin infiltration will depend in part on the maintenance procedures,
such as those outlined below.
Before annual storm seasons and following rainfall events producing precipitation of 0.5 inches
or more:
• Maintain landscaping and irrigation system as needed.
• Remove debris and litter from the entire basin to minimize clogging and improve
aesthetics.
• Inspect for obvious problems and repair as needed. Address odor, insects, and
overgrowth issues associated with stagnant or standing water in the basin bottom. No
standing water should be present longer than 72 hours.
• Check for erosion and sediment laden areas in the basin. Repair as needed.
• Re-stabilize the basin slopes as needed.
Perform the following inspection procedures within 72 hours after a rainfall event producing
precipitation of 0.5 inches or greater:
• Examine the tributary inlet for blockage, the embankment and spillway integrity, as well
as damage to any structural element.
• Check for erosion, slumping and overgrowth. Repair as needed.
• Check basin depth for sediment build up and reduced total capacity. Scrape bottom as
needed and remove sediment. Restore to original cross‐section and infiltration rate.
Replant basin vegetation.
• No water should be present 72 hours after a rainfall event. No long-term standing water
should be present at all. No algae formation should be visible.
Record Keeping: A copy of this project-specific WQMP shall be maintained on-site or remotely
by the project owner or operator (Property Manager). Records of maintenance shall be appended
to this WQMP based on the information provided by the contracted management.
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
March 2, 2022 28
VII. Funding
The funding source for operation and maintenance of each BMP identified in the Project Specific
Preliminary Water Quality Management Plan shall be the responsibility of Meriwether
Companies. The owner recognizes that a source of funding is required to support the on-going
operation and maintenance of BMPs, and that funding will continue for the life of the project.
By certifying the final project specific WQMP, the Project applicant is certifying that the funding
responsibilities have been addressed and will be transferred to future owners. One example of
how to adhere to the requirement to transfer operation and maintenance responsibilities is to
record the project specific WQMP against the title to the property.
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
Appendix A
CONDITIONS OF APPROVAL
(TO BE PROVIDED)
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
Appendix B
VICINITY MAP, WQMP SITE PLAN, AND RECEIVING WATERS MAP
MAP OF RECEIVING WATERS
0 2 4MI.
PROJECTSITE
WHITEWATER RIV ER COAC HELLA VALLEY STOR M WATER CHANNEL
AVENUE 58
MADISON STREETNOPARKINGNOPARKINGGGSTREET "A
"
Prop. Building
No. 2
Prop.
Building
No. 1
Prop.
Building
No. 3A = 7.8
DA-A
EXHIBIT DATE:
THE CORNERPROJECT NAME:
TENTATIVE TRACT MAP NO. 37815, LOTS 134-138MAP NUMBER:
PRELIMINARY WATER QUALITY MANAGEMENT PLANPLAN:
MARCH 2022
MSA CONSULTING, INC.
> PLANNING > CIVIL ENGINEERING > LAND SURVEYING
34200 Bob Hope Drive, Rancho Mirage, CA 92270
760.320.9811 msaconsultinginc.com
SAW
DESIGN BY
DRAWN BY
CHECK BY
DG
JHC
LEGEND
PROJECT BOUNDARY
COMMERCIAL
DRAINAGE OVERFLOW DIRECTION
DRAINAGE SUB-AREA ID
AREA (AC)
FALLOW WITH SURFACE RETENTION
A
DA
AC.
DA
ELEV.
ACREAGE
DRAINAGE AREA
ELEVATION
EX.
PROP.
RET.
EXISTING
PROPOSED
RETENTION
SUMMARY OF DRAINAGE AREA RETENTION CAPACITY
A 7.8 AC.5.7 AC. (73%)5,934 CF 78,605 CF
DRAINAGE
AREA
DRAINAGE
AREA ID
IMPERVIOUS AREA
AND PERCENTAGE
WQMP STORMWATER
VOLUME (VBMP)
PROVIDED
RETENTION CAPACITY
IN FALLOW AREAS
ABBREVIATIONS
DRAINAGE DIRECTION
R:\2553\ACAD\Grading\WQMP\The Corner\2553 WQMP - CORNER.dwg, 3/3/2022 10:32:47 AM, dgallerani, MSA Consulting, Inc.
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
Appendix C
SUPPORTING DETAIL RELATED TO HYDROLOGIC CONDITIONS OF CONCERN
(NOT APPLICABLE – SEE APPENDIX F FOR HYDROLOGY REPORT SUMMARY)
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
Appendix D
EDUCATIONAL MATERIALS
CHECKLIST FOR MINIMIZING VECTOR PRODUCTION IN STORMWATER MANAGEMENT STRUCTURES
CALIFORNIA STORMWATER BMP HANDBOOK - MUNICIPAL
SC-35: Safer Alternative Products
SC-41: Building and Grounds Maintenance
SC-43: Parking/Storage Area Maintenance
SC-70: Road and Street Maintenance
SC-71: Plaza and Sidewalk Cleaning
SC-73: Landscape Maintenance
SC-74: Drainage System Maintenance
SD-12: Efficient Irrigation
SD-13: Storm Drain Signage
TC-11: Infiltration Basin
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
Appendix E
SOILS REPORT
Hydrologic Soil Group—Riverside County, Coachella Valley Area, California
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
2/8/2022
Page 1 of 437207403720820372090037209803721060372114037212203720740372082037209003720980372106037211403721220569010569090569170569250569330569410569490569570569650569730
569010 569090 569170 569250 569330 569410 569490 569570 569650 569730
33° 37' 43'' N 116° 15' 22'' W33° 37' 43'' N116° 14' 52'' W33° 37' 26'' N
116° 15' 22'' W33° 37' 26'' N
116° 14' 52'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 11N WGS84
0 150 300 600 900
Feet
0 50 100 200 300
Meters
Map Scale: 1:3,540 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: Riverside County, Coachella Valley Area,
California
Survey Area Data: Version 13, Sep 15, 2021
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Feb 3, 2021—May
27, 2021
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Hydrologic Soil Group—Riverside County, Coachella Valley Area, California
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
2/8/2022
Page 2 of 4
Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
CpA Coachella fine sand, 0
to 2 percent slopes
A 12.9 27.1%
CsA Coachella fine sandy
loam, 0 to 2 percent
slopes
A 10.7 22.3%
GcA Gilman fine sandy loam,
wet, 0 to 2 percent
slopes
B 1.1 2.3%
Ir Indio fine sandy loam,
wet
B 23.0 48.2%
Totals for Area of Interest 47.7 100.0%
Hydrologic Soil Group—Riverside County, Coachella Valley Area, California
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
2/8/2022
Page 3 of 4
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff: None Specified
Tie-break Rule: Higher
Hydrologic Soil Group—Riverside County, Coachella Valley Area, California
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
2/8/2022
Page 4 of 4
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
Appendix F
STRUCTURAL BMP AND/OR RETENTION FACILITY SIZING CALCULATIONS
AND DESIGN DETAILS
SUMMARY OF PRELIMINARY HYDROLOGY REPORT FOR
CORAL MOUNTAIN RESORT: THE CORNER
ATRIB = 7.800 acres
Determine the Impervious Area Within ATRIB (AIMP)AIMP = 5.700 acres
Calculate the Impervious Area Ratio (IF)
IF = AIMP/ATRIB IF = 0.73
Use the following equation based on the WEF/ASCE Method
CBMP = 0.858If3 - 0.78If2 + 0.774If + 0.04 CBMP = 0.52
Calculate VU, the 80% Unit Storage Volume VU = 0.40 x CBMP VU = 0.21 (in*ac)/ac
Calculate the design storage volume of the BMP, VBMP
VBMP (ft3) =VBMP = 5,934 ft3
QBMP = CBMP x I x ATRIB QBMP = 0.82 ft3/s
I = Design Rainfall Intensity, 0.2 in/hr
Notes:
BMP Design Flow Rate, QBMP
Company Name
Designed By
Company Project Number/Name
Drainage Area Number/Name
2553 Coral Mountain Resort: The Corner
DA-A
March 2, 2022
VU (in-ac/ac) x AT (ac) x 43,560 (ft2/ac)
12(in/ft)
Calculate the Composite Runoff Coefficient, C for the BMP Tributary Area
Determine Design Storage Volume, VBMP
Legend:Required Entries
Calculated Cells
Determine the Impervious Area Ratio
Whitewater Watershed
BMP Design Volume, VBMP & Design Flow Rate , QBMP (Rev. 06-2014)
Enter the Area Tributary to this Feature (ATRIB)
MSA Consulting, Inc
MSA Consulting, Inc
Date
County/City Case No.
PROECT
JOB No.
BASIN DESIGNATION:
BASIN CHARACTERISTICS
CONTOUR
ELEVATION INCR TOTAL INCR TOTAL INCR
(ft) (ft) (sf) (sf) (cuft) (cuft) (acre-ft)
455 0 0 74,929 0 0 0.00
456 1 1 7,410 82,339 78,605 78,605 1.80
WHERE:
TOTAL
Agriculture Areas
BASIN VOLUME WORKSHEET
DEPTH AREA VOLUME
The Corner
2553
2121213
1 AAAAEEV
Basin Volume Worksheet
Page 13 of 13
NOPARKINGNOPARKINGMSA CONSULTING,INC.
> PLANNING > CIVIL ENGINEERING > LAND SURVEYING
34200 Bob Hope Drive, Rancho Mirage, CA 92270
760.320.9811 msaconsultinginc.com
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
Appendix G
AGREEMENTS – CC&RS, COVENANT AND AGREEMENTS, BMP
MAINTENANCE AGREEMENTS AND/OR OTHER
MECHANISMS FOR ENSURING ONGOING OPERATION,
MAINTENANCE, FUNDING AND TRANSFER OF
REQUIREMENTS FOR THIS PROJECT-SPECIFIC WQMP
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
Appendix H
PHASE 1 ENVIRONMENTAL SITE ASSESSMENT – SUMMARY OF SITE
REMEDIATION CONDUCTED AND USE RESTRICTIONS
(NOT AVAILABLE)
Whitewater River Region WQMP
Coral Mountain Resort: The Corner
Appendix I
PROJECT-SPECIFIC WQMP SUMMARY DATA FORM
Project-Specific WQMP Summary Data Form
Applicant Information
Name and Title Garrett Simon
Company Meriwether Companies
Phone (303) 395-3150
Email gsimon@meriwetherco.com
Project Information
Project Name
(as shown on project application/project-specific WQMP) Coral Mountain Resort: The Corner
Street Address South of Avenue 58; West of Madison Street
Nearest Cross Streets Madison Street
Municipality
(City or Unincorporated County) City of La Quinta
Zip Code 92253
Tract Number(s) and/or Assessor Parcel Number(s) Tentative Tract Map No. 37815
Other
(other information to help identify location of project)
Indicate type of project. Priority Development Projects (Use an "X" in cell preceding project type):
SF hillside residence; impervious area ≥ 10,000 sq. ft.; Slope ≥ 25%
SF hillside residence; impervious area ≥ 10,000 sq. ft.; Slope ≥ 10% & erosive soils
X Commercial or Industrial ≥ 100,000 sq. ft. (Commercial Only)
Automotive repair shop
X Retail Gasoline Outlet disturbing > 5,000 sq. ft.
X Restaurant disturbing > 5,000 sq. ft.
X Home subdivision ≥ 10 housing units
X Parking lot ≥ 5,000 sq. ft. or ≥ 25 parking spaces
Date Project-Specific WQMP Submitted March 2, 2022
Size of Project Area (nearest 0.1 acre) 7.8 Acres
Will the project replace more than 50% of the impervious
surfaces on an existing developed site? No
Project Area managed with LID/Site Design BMPs (nearest 0.1
acre) 7.8 Acres
Are Treatment Control BMPs required? No
Is the project subject to onsite retention by ordinance or policy? Yes
Did the project meet the 100% LID/Site Design Measurable
Goal? Yes
Name of the entity that will implement, operate, and maintain
the post-construction BMPs Meriwether Companies
Contact Name Garrett Simon
Street or Mailing Address 2440 Junction Place, Suite 200
City Boulder, CO
Zip Code 80301
Phone (303) 395-3150
Space Below for Use by City/County Staff Only
Preceding Information Verified by
(consistent with information in project-specific WQMP)
Name:
Date:
Date Project-Specific WQMP Approved:
Data Entered by Name:
Date:
Other Comments