HomeMy WebLinkAboutAppdx F-2_WQMPPreliminary Water Quality
Management Plan
For:
CITRUS INDUSTRIAL DEVELOPMENT
EAST OF CITRUS AVENUE,
BETWEEN SLOVER AVENUE AND BOYLE AVENUE,
CITY OF FONTANA, CA
APN: 0251-151-03 TO 07, 09, 10, 14 TO 16, 18 TO 22, 39 TO 44
WQMP: 22-000059
PM: 16055
DRP: 22-000049
Prepared for:
CHIPT Fontana Citrus Boyle, L.P.
527 W. 7th Street, Suite 200
Los Angeles, CA 90014
909.358.7715
Prepared by:
Langan Engineering & Environmental Services, Inc.
11801 Piece Street
Riverside, CA 92505
951.710.3000
Submittal Date: 04/21/2023
Revision Date: Insert Current Revision Date
Approval Date:_____________________
Water Quality Management Plan (WQMP)
Owner’s Certification
Project Owner’s Certification
This Water Quality Management Plan (WQMP) has been prepared for Crow Holding Industrial by Langan
Engineering & Environmental Services, Inc. The WQMP is intended to comply with the requirements of the
City of Fontana and the NPDES Areawide Stormwater Program requiring the preparation of a WQMP. The
undersigned, while it owns the subject property, is responsible for the implementation of the provisions of
this plan and will ensure that this plan is amended as appropriate to reflect up-to-date conditions on the
site consistent with San Bernardino County’s Municipal Storm Water Management Program and the intent
of the NPDES Permit for San Bernardino County and the incorporated cities of San Bernardino County
within the Santa Ana Region. Once the undersigned transfers its interest in the property, its successors in
interest and the city/county shall be notified of the transfer. The new owner will be informed of its
responsibility under this WQMP. A copy of the approved WQMP shall be available on the subject site in
perpetuity.
“I certify under a penalty of law that the provisions (implementation, operation, maintenance, and funding)
of the WQMP have been accepted and that the plan will be transferred to future successors.”
.
Project Data
Permit/Application
Number(s):
WQMP: 22-000059
DRP: 22-000049 Grading Permit Number(s):
Tract/Parcel Map
Number(s): PM: 16055 Building Permit Number(s):
CUP, SUP, and/or APN (Specify Lot Numbers if Portions of Tract): APN: 0251-151-03 TO 07, 09, 10, 14
TO 16, 18 TO 22, 39 TO 44
Owner’s Signature
Owner Name: Jorge A. Garcia
Title Development Associate
Company CHIPT Fontana Citrus Boyle, L.P.
Address 527 W. 7th Street, Suite 200 Los Angeles CA 90014
Email jagarcia@crowholdings.com
Telephone # 909.358.7715
Signature Date
Water Quality Management Plan (WQMP)
Contents
Preparer’s Certification
Project Data
Permit/Application
Number(s):
WQMP: 22-000059
DRP: 22-000049 Grading Permit Number(s):
Tract/Parcel Map
Number(s): PM: 16055 Building Permit Number(s):
CUP, SUP, and/or APN (Specify Lot Numbers if Portions of Tract):
APN: 0251-151-03 TO 07, 09,
10, 14 TO 16, 18 TO 22, 39
TO 44
“The selection, sizing and design of stormwater treatment and other stormwater quality and quantity control
measures in this plan were prepared under my oversight and meet the requirements of Regional Water Quality
Control Board Order No. R8-2010-0036.”
Engineer: Michael Golias PE Stamp Below
Title Principal
Company Langan Engineering & Environmental Services, Inc.
Address 11801 Piece Street
Email mgolias@langan.com
Telephone # 949.561.9215
Signature
Date
Water Quality Management Plan (WQMP)
Contents ii
Table of Contents
Section 1 Discretionary Permits ......................................................................................... 1-1
Section 2 Project Description ............................................................................................... 2-1
2.1 Project Information ........................................................................................ 2-1
2.2 Property Ownership / Management .............................................................. 2-2
2.3 Potential Stormwater Pollutants ................................................................... 2-3
2.4 Water Quality Credits ........ ……………………………………………………………………………. 2-4
Section 3 Site and Watershed Description ......................................................................... 3-1
Section 4 Best Management Practices ................................................................................ 4-1
4.1 Source Control BMP ....................................................................................... 4-1
4.1.1 Pollution Prevention ................................................................................... 4-1
4.1.2 Preventative LID Site Design Practices ....................................................... 4-7
4.2 Project Performance Criteria......................................................................... 4-8
4.3 Project Conformance Analysis ....................................................................... 4-13
4.3.1 Site Design Hydrologic Source Control BMP .............................................. 4-15
4.3.2 Infiltration BMP .......................................................................................... 4-19
4.3.3 Harvest and Use BMP .................................................................................. 4-22
4.3.4 Biotreatment BMP....................................................................................... 4-23
4.3.5 Conformance Summary ............................................................................... 4-27
4.3.6 Hydromodification Control BMP ............................................................... 4-29
4.4 Alternative Compliance Plan (if applicable) ................................................. 4-30
Section 5 Inspection & Maintenance Responsibility Post Construction BMPs ................. 5-1
Section 6 WQMP Attachments ............................................................................................ 6-1
6.1. Site Plan and Drainage Plan.......................................................................... 6-2
6.2 Electronic Data Submittal ............................................................................. 6-3
6.3 Post Construction .......................................................................................... 6-4
6.4 Other Supporting Documentation ................................................................ 6-5
6.4.1 Vicinity Map ............................................................................................ 6-6
6.4.2 Treatment BMP Factsheet ...................................................................... 6-7
6.4.3 Manufacturer’s Specification and Details .............................................. 6-8
6.4.4 NOAA Atlas 14 Rainfall Data ................................................................... 6-9
6.4.5 Factor of Safety Worksheet ..................................................................... 6-10
Forms
Form 1-1 Project Information ............................................................................................... 1-1
Form 2.1-1 Description of Proposed Project ......................................................................... 2-1
Form 2.2-1 Property Ownership/Management ..................................................................... 2-2
Form 2.3-1 Pollutants of Concern ......................................................................................... 2-3
Form 2.4-1 Water Quality Credits ......................................................................................... 2-4
Form 3-1 Site Location and Hydrologic Features ................................................................. 3-1
Form 3-2 Hydrologic Characteristics .................................................................................... 3-2
Form 3-3 Watershed Description .......................................................................................... 3-4
Form 4.1-1 Non-Structural Source Control BMP ................................................................... 4-2
Water Quality Management Plan (WQMP)
Contents iii
Form 4.1-2 Structural Source Control BMP .......................................................................... 4-5
Form 4.1-3 Site Design Practices Checklist ........................................................................... 4-7
Form 4.2-1 LID BMP Performance Criteria for Design Capture Volume ............................. 4-8
Form 4.2-2 Summary of HCOC Assessment .......................................................................... 4-9
Form 4.2-3 HCOC Assessment for Runoff Volume ............................................................... 4-10
Form 4.2-4 HCOC Assessment for Time of Concentration .................................................. 4-11
Form 4.2-5 HCOC Assessment for Peak Runoff .................................................................... 4-12
Form 4.3-1 Infiltration BMP Feasibility ................................................................................ 4-14
Form 4.3-2 Site Design Hydrologic Source Control BMP ..................................................... 4-15
Form 4.3-3 Infiltration LID BMP ........................................................................................... 4-20
Form 4.3-4 Harvest and Use BMP ......................................................................................... 4-22
Form 4.3-5 Selection and Evaluation of Biotreatment BMP ................................................ 4-23
Form 4.3-6 Volume Based Biotreatment – Bioretention and Planter Boxes w/Underdrains 4-24
Form 4.3-7 Volume Based Biotreatment- Constructed Wetlands and Extended Detention 4-25
Form 4.3-8 Flow Based Biotreatment ................................................................................... 4-26
Form 4.3-9 Conformance Summary and Alternative Compliance Volume Estimate .......... 4-27
Form 4.3-10 Hydromodification Control BMP ..................................................................... 4-29
Form 5-1 BMP Inspection and Maintenance ........................................................................ 5-1
Water Quality Management Plan (WQMP)
1-1
Section 1 Discretionary Permit(s)
Form 1-1 Project Information
Project Name Citrus Industrial Development
Project Owner Contact Name: Jorge Garcia
Mailing
Address:
527 W. 7th Street, Suite 200, Los Angeles,
CA 90014
E-mail
Address: jgarcia@crowholdings.com Telephone: 909.358.7715
Permit/Application Number(s): WQMP: 22-000059
DRP: 22-000049
Tract/Parcel Map
Number(s): PM: 16055
Additional Information/
Comments:
Description of Project:
The project is located in the City of Fontana, east of Citrus Avenue and between Slover
Avenue and Boyle Avenue. The proposed development will demolish the existing buildings
and other site improvements and to be replaced with an industrial warehouse building. The
project area is approximately 16.12 acres. Typical site improvements for the warehouse
building include loading docks, trailer parking, and vehicular parking. Landscaping is
proposed around the perimeter of the site and adjacent to the building where it is
appropriate. The warehouse building footprint is 359,157 SF in size.
Provide summary of Conceptual
WQMP conditions (if previously
submitted and approved). Attach
complete copy.
N/A
Water Quality Management Plan (WQMP)
2-1
Section 2 Project Description
2.1 Project Information
This section of the WQMP should provide the information listed below. The information provided for
Conceptual/ Preliminary WQMP should give sufficient detail to identify the major proposed site design and LID
BMPs and other anticipated water quality features that impact site planning. Final Project WQMP must
specifically identify all BMP incorporated into the final site design and provide other detailed information as
described herein.
The purpose of this information is to help determine the applicable development category, pollutants of
concern, watershed description, and long term maintenance responsibilities for the project, and any applicable
water quality credits. This information will be used in conjunction with the information in Section 3, Site
Description, to establish the performance criteria and to select the LID BMP or other BMP for the project or
other alternative programs that the project will participate in, which are described in Section 4.
Form 2.1-1 Description of Proposed Project
1 Development Category (Select all that apply):
Significant re-development
involving the addition or
replacement of 5,000 ft2 or
more of impervious surface on
an already developed site
New development involving
the creation of 10,000 ft2 or
more of impervious surface
collectively over entire site
Automotive repair
shops with standard
industrial classification (SIC)
codes 5013, 5014, 5541,
7532- 7534, 7536-7539
Restaurants (with SIC
code 5812) where the land
area of development is
5,000 ft2 or more
Hillside developments of
5,000 ft2 or more which are
located on areas with known
erosive soil conditions or
where the natural slope is
25 percent or more
Developments of 2,500 ft2
of impervious surface or more
adjacent to (within 200 ft) or
discharging directly into
environmentally sensitive areas
or waterbodies listed on the
CWA Section 303(d) list of
impaired waters.
Parking lots of 5,000 ft2
or more exposed to storm
water
Retail gasoline outlets
that are either 5,000 ft2 or
more, or have a projected
average daily traffic of 100
or more vehicles per day
Non-Priority / Non-Category Project May require source control LID BMPs and other LIP requirements. Please consult with local
jurisdiction on specific requirements.
2 Project Area (ft2): 702,187 SF
(16.12 acres)
3 Number of Dwelling Units: 4 SIC Code: 4225
5 Is Project going to be phased? Yes No If yes, ensure that the WQMP evaluates each phase as a distinct DA, requiring LID
BMPs to address runoff at time of completion.
6 Does Project include roads? Yes No If yes, ensure that applicable requirements for transportation projects are addressed (see
Appendix A of TGD for WQMP)
Water Quality Management Plan (WQMP)
2-2
2.2 Property Ownership/Management
Describe the ownership/management of all portions of the project and site. State whether any infrastructure
will transfer to public agencies (City, County, Caltrans, etc.) after project completion. State if a homeowners or
property owners association will be formed and be responsible for the long-term maintenance of project
stormwater facilities. Describe any lot-level stormwater features that will be the responsibility of individual
property owners.
Form 2.2-1 Property Ownership/Management
Describe property ownership/management responsible for long-term maintenance of WQMP stormwater facilities:
Crow Holdings Industrial
527 W. 7th Street, Suite 200
Los Angeles, CA 90014
The property owner will maintain onsite WQMP stormwater facilities.
Water Quality Management Plan (WQMP)
2-3
2.3 Potential Stormwater Pollutants
Determine and describe expected stormwater pollutants of concern based on land uses and site activities (refer
to Table 3-3 in the TGD for WQMP).
Form 2.3-1 Pollutants of Concern
Pollutant
Please check:
E=Expected, N=Not
Expected
Additional Information and Comments
Pathogens (Bacterial / Virus) E N Bacteria indicators are routinely detected in pavement runoff.
Including petroleum hydrocarbons.
Nutrients - Phosphorous E N Expected pollutants if landscaping exists on site.
Nutrients - Nitrogen E N Expected pollutants if landscaping exists on site.
Noxious Aquatic Plants E N Expected pollutants if landscaping exists on site.
Sediment E N Expected pollutants if landscaping exists on site.
Metals E N
Oil and Grease E N
Trash/Debris E N
Pesticides / Herbicides E N
Organic Compounds E N Expected pollutants if landscaping exists on site.
Other: E N
Other: E N
Other: E N
Other: E N
Other: E N
Water Quality Management Plan (WQMP)
2-4
2.4 Water Quality Credits
A water quality credit program is applicable for certain types of development projects if it is not feasible to meet
the requirements for on-site LID. Proponents for eligible projects, as described below, can apply for water
quality credits that would reduce project obligations for selecting and sizing other treatment BMP or
participating in other alternative compliance programs. Refer to Section 6.2 in the TGD for WQMP to
determine if water quality credits are applicable for the project.
Form 2.4-1 Water Quality Credits
1 Project Types that Qualify for Water Quality Credits: Select all that apply
Redevelopment projects that
reduce the overall impervious
footprint of the project site.
[Credit = % impervious reduced]
Higher density
development projects
Vertical density [20%]
7 units/ acre [5%]
Mixed use development,
(combination of residential,
commercial, industrial, office,
institutional, or other land uses
which incorporate design principles
that demonstrate environmental
benefits not realized through single
use projects) [20%]
Brownfield
redevelopment
(redevelop real property
complicated by presence
or potential of hazardous
contaminants) [25%]
Redevelopment projects in
established historic district,
historic preservation area, or
similar significant core city center
areas [10%]
Transit-oriented
developments (mixed use
residential or commercial
area designed to maximize
access to public
transportation) [20%]
In-fill projects (conversion of
empty lots & other underused
spaces < 5 acres, substantially
surrounded by urban land uses, into
more beneficially used spaces, such
as residential or commercial areas)
[10%]
Live-Work
developments (variety of
developments designed
to support residential and
vocational needs) [20%]
2 Total Credit % (Total all credit percentages up to a maximum allowable credit of 50 percent)
Description of Water Quality
Credit Eligibility (if applicable)
N/A
Water Quality Management Plan (WQMP)
3-1
Section 3 Site and Watershed Description
Describe the project site conditions that will facilitate the selection of BMP through an analysis of the physical
conditions and limitations of the site and its receiving waters. Identify distinct drainage areas (DA) that collect
flow from a portion of the site and describe how runoff from each DA (and sub-watershed DMAs) is conveyed
to the site outlet(s). Refer to Section 3.2 in the TGD for WQMP. The form below is provided as an example.
Then complete Forms 3.2 and 3.3 for each DA on the project site. If the project has more than one
drainage area for stormwater management, then complete additional versions of
these forms for each DA / outlet.
Form 3-1 Site Location and Hydrologic Features
Site coordinates take GPS
measurement at approximate
center of site
Latitude 34.06427 Longitude -117.44969 Thomas Bros Map page
1 San Bernardino County climatic region: Valley Mountain
2 Does the site have more than one drainage area (DA): Yes No If no, proceed to Form 3-2. If yes, then use this form to show a
conceptual schematic describing DMAs and hydrologic feature connecting DMAs to the site outlet(s). An example is provided below that can be
modified for proposed project or a drawing clearly showing DMA and flow routing may be attached
Conveyance Briefly describe on-site drainage features to convey runoff that is not retained within a DMA
DA1 To Outlet 1 All drainage will be captured by the proposed on-site storm systems and discharged into a proposed
underground infiltration chamber (A).
DA2 to Outlet 2 All drainage will be captured by the proposed on-site storm systems and discharged into a proposed
underground infiltration chamber (B).
Outlet 1
DA1
Outlet 2
DA2
Water Quality Management Plan (WQMP)
3-2
Form 3-2 Existing Hydrologic Characteristics for Drainage Area 1
For Drainage Area 1’s sub-watershed DMA,
provide the following characteristics DMA A
1 DMA drainage area (ft2) 104,544
2 Existing site impervious area (ft2) 9,377
3 Antecedent moisture condition For desert
areas, use
http://www.sbcounty.gov/dpw/floodcontrol/pdf/2
0100412_map.pdf
AMC II
4 Hydrologic soil group Refer to Watershed
Mapping Tool –
http://permitrack.sbcounty.gov/wap/
HSG A
5 Longest flowpath length (ft) 565
6 Longest flowpath slope (ft/ft) 0.012
7 Current land cover type(s) Select from Fig C-3
of Hydrology Manual SFR
8 Pre-developed pervious area condition:
Based on the extent of wet season vegetated cover
good >75%; Fair 50-75%; Poor <50% Attach photos
of site to support rating
See Appendix A-Google Aerial Photo
Poor
Water Quality Management Plan (WQMP)
3-3
Form 3-2 Existing Hydrologic Characteristics for Drainage Area 2
For Drainage Area 2’s sub-watershed DMA,
provide the following characteristics DMA B
1 DMA drainage area (ft2) 598,078
2 Existing site impervious area (ft2) 118,474
3 Antecedent moisture condition For desert
areas, use
http://www.sbcounty.gov/dpw/floodcontrol/pdf/2
0100412_map.pdf
AMC II
4 Hydrologic soil group Refer to Watershed
Mapping Tool –
http://permitrack.sbcounty.gov/wap/
HSG A
5 Longest flowpath length (ft) 1,005
6 Longest flowpath slope (ft/ft) 0.012
7 Current land cover type(s) Select from Fig C-3
of Hydrology Manual SFR
8 Pre-developed pervious area condition:
Based on the extent of wet season vegetated cover
good >75%; Fair 50-75%; Poor <50% Attach photos
of site to support rating
Poor
Water Quality Management Plan (WQMP)
3-4
Form 3-3 Watershed Description for Drainage Area
Receiving waters
Refer to Watershed Mapping Tool -
http://permitrack.sbcounty.gov/wap/
See ‘Drainage Facilities” link at this website
San Sevaine Channel
Santa Ana River, Reach 3
Prado Dam
Santa Ana River, Reach 2
Santa Ana River, Reach 1
Pacific Ocean
Applicable TMDLs
Refer to Local Implementation Plan
San Sevaine Channel: None
Santa Ana River, Reach 3: Pathogens, Nitrate
Prado Dam: Pathogens
Santa Ana River, Reach 2: None
Santa Ana River, Reach 1: None
Pacific Ocean: None
303(d) listed impairments
Refer to Local Implementation Plan and Watershed
Mapping Tool –
http://permitrack.sbcounty.gov/wap/ and State
Water Resources Control Board website –
http://www.waterboards.ca.gov/santaana/water_iss
ues/programs/tmdl/index.shtml
San Sevaine Channel: None
Santa Ana River, Reach 3: Copper, Indicator Bacteria, Lead
Prado Dam: pH
Santa Ana River, Reach 2: None
Santa Ana River, Reach 1: None
Pacific Ocean: None
Environmentally Sensitive Areas (ESA)
Refer to Watershed Mapping Tool –
http://permitrack.sbcounty.gov/wap/
N/A
Unlined Downstream Water Bodies
Refer to Watershed Mapping Tool –
http://permitrack.sbcounty.gov/wap/
Hydrologic Conditions of Concern
Yes Complete Hydrologic Conditions of Concern (HCOC) Assessment. Include Forms
4.2-2 through Form 4.2-5 and Hydromodification BMP Form 4.3-10 in submittal
No
Watershed–based BMP included in a RWQCB
approved WAP
Yes Attach verification of regional BMP evaluation criteria in WAP
• More Effective than On-site LID
• Remaining Capacity for Project DCV
• Upstream of any Water of the US
• Operational at Project Completion
• Long-Term Maintenance Plan
No
Water Quality Management Plan (WQMP)
4-1
Section 4 Best Management Practices (BMP)
4.1 Source Control BMP
4.1.1 Pollution Prevention
Non-structural and structural source control BMP are required to be incorporated into all new development
and significant redevelopment projects. Form 4.1-1 and 4.1-2 are used to describe specific source control BMPs
used in the WQMP or to explain why a certain BMP is not applicable. Table 7-3 of the TGD for WQMP provides
a list of applicable source control BMP for projects with specific types of potential pollutant sources or activities.
The source control BMP in this table must be implemented for projects with these specific types of potential
pollutant sources or activities.
The preparers of this WQMP have reviewed the source control BMP requirements for new development and
significant redevelopment projects. The preparers have also reviewed the specific BMP required for project as
specified in Forms 4.1-1 and 4.1-2. All applicable non-structural and structural source control BMP shall be
implemented in the project.
Water Quality Management Plan (WQMP)
4-2
Form 4.1-1 Non-Structural Source Control BMPs
Identifier Name
Check One Describe BMP Implementation OR,
if not applicable, state reason Included Not
Applicable
N1 Education of Property Owners, Tenants
and Occupants on Stormwater BMPs
Owner/tenant shall be familiarized with the educational materials in the attachment
and the contents of the WQMP
N2 Activity Restrictions Activities shall be restricted to that allowed by local governing agencies.
N3 Landscape Management BMPs
Irrigation shall be consistent with San Bernardino’s Water Conservation Ordinance.
Fertilizer and pesticide usage will be consistent with County Management Guidelines for
Use of Fertilizer and Pesticides. Landscape will be inspected and maintained weekly by a
qualified contractor and all landscape waste will be disposed of properly.
N4 BMP Maintenance
BMP shall be inspected and maintained in accordance with manufacturer’s
recommendations. BMPs shall be maintained in accordance with the WQMP Operations
and Maintenance Plan.
N5 Title 22 CCR Compliance
(How development will comply)
No hazardous waste expected to be kept on site.
N6 Local Water Quality Ordinances Owner/tenant shall comply with the requirements of the Local Water Quality
Ordinances.
N7 Spill Contingency Plan Owner/tenant shall have site specific Spill Contingency Plan consistent with the site
usage and potential for spills.
N8 Underground Storage Tank Compliance Owner/tenant shall comply with the requirements for the underground storage tank
compliance.
N9 Hazardous Materials Disclosure
Compliance
No hazardous materials expected to be stored on site.
Water Quality Management Plan (WQMP)
4-3
Form 4.1-1 Non-Structural Source Control BMPs
Identifier Name
Check One Describe BMP Implementation OR,
if not applicable, state reason Included Not
Applicable
N10 Uniform Fire Code Implementation Owner shall comply with Article 80 of the Uniform Fire Code as enforced by the local fire
protection agency.
N11 Litter/Debris Control Program A litter/debris control program shall be implemented as part of the site regularly
scheduled maintenance.
N12 Employee Training
The owner will ensure that tenants are also familiar with onsite BMPs and necessary
maintenance required of the tenants. Employees shall be trained to clean up minor spills
and participate in ongoing maintenance.
N13 Housekeeping of Loading Docks
Loading docks should be kept in a clean and orderly condition through a regular
program of sweeping and litter control and immediate cleanup of spills and broken
containers. Cleanup procedures should minimize or eliminate the use of water. If wash
water is used, it must be disposed of in an approved manner and not discharged to the
storm drain system.
N14 Catch Basin Inspection Program
At least 80 percent of drainage facilities shall be inspected, cleaned and maintained on
an annual basis with 100 percent of the facilities included in a two-year period. Cleaning
should take place in the late summer/early fall prior to the start of the rainy season.
Drainage facilities include catch basins (storm drain inlets), detention or retention
basins, and infiltration system.
N15 Vacuum Sweeping of Private Streets and
Parking Lots
Driveways, and parking lots are required to be swept on a regular frequency based
usage and field observations of waste accumulation, using a vacuum assisted
sweeper. All paved areas of a business shall be swept, in late summer or early fall,
prior to the start of the rainy season or equivalent, as required by the governing
jurisdiction.
N16 Other Non-structural Measures for Public
Agency Projects
Not a public agency project.
Water Quality Management Plan (WQMP)
4-4
N17 Comply with all other applicable NPDES
permits
Will comply with Construction General Permit.
Water Quality Management Plan (WQMP)
4-5
Form 4.1-2 Structural Source Control BMPs
Identifier Name
Check One Describe BMP Implementation OR,
If not applicable, state reason Included Not
Applicable
S1 Provide storm drain system stencilling and signage
(CASQA New Development BMP Handbook SD-13)
“No Dumping – Drains to Ocean” stencils will be applied. Legibility of stencil will be
inspected annually for legibility and corrected as necessary, and at a minimum re-
applied at least once every 5 years.
S2
Design and construct outdoor material storage
areas to reduce pollution introduction (CASQA
New Development BMP Handbook SD-34)
Outdoor storage areas shall be paved and sufficiently impervious to leaks and
spills.
S3
Design and construct trash and waste storage
areas to reduce pollution introduction (CASQA
New Development BMP Handbook SD-32)
Outdoor trash and waste storage areas shall be paved with impervious material,
and trash bins shall have solid covered lids.
S4
Use efficient irrigation systems & landscape
design, water conservation, smart controllers, and
source control (Statewide Model Landscape
Ordinance; CASQA New Development BMP
Handbook SD-12)
Irrigation systems shall include shutoff valves triggered by a pressure drop to
control water loss in the event of broken sprinkler heads or lines. Timers will be
used to avoid over watering and watering cycles and duration shall be adjusted
seasonally by the landscape maintenance contractor. The landscaping areas will be
grouped with plants that have similar water requirements. Native or drought
tolerant species shall also be used where appropriate to reduce excess irrigation
runoff and promote surface filtration.
S5
Finish grade of landscaped areas at a minimum of
1-2 inches below top of curb, sidewalk, or
pavement
Landscape areas will be depressed at a minimum 1” below top of curb or sidewalk.
S6
Protect slopes and channels and provide energy
dissipation (CASQA New Development BMP
Handbook SD-10)
No onsite channels or slopes to protect.
S7 Covered dock areas (CASQA New Development
BMP Handbook SD-31)
Dock areas shall be maintained and swept in accordance to the site’s regularly
scheduled maintenance program. Debris and trash shall be picked up, and
disposed.
S8
Covered maintenance bays with spill containment
plans (CASQA New Development BMP Handbook
SD-31)
No maintenance bays onsite.
Water Quality Management Plan (WQMP)
4-6
S9 Vehicle wash areas with spill containment plans
(CASQA New Development BMP Handbook SD-33)
No vehicle wash areas onsite.
S10 Covered outdoor processing areas (CASQA New
Development BMP Handbook SD-36)
No outdoor processing areas onsite.
Form 4.1-2 Structural Source Control BMPs
Identifier Name
Check One Describe BMP Implementation OR,
If not applicable, state reason Included Not
Applicable
S11
Equipment wash areas with spill containment
plans (CASQA New Development BMP Handbook
SD-33)
No equipment wash areas onsite.
S12 Fueling areas (CASQA New Development BMP
Handbook SD-30)
No fueling areas onsite.
S13 Hillside landscaping (CASQA New Development
BMP Handbook SD-10)
No hillside onsite.
S14 Wash water control for food preparation areas No food preparation onsite.
S15 Community car wash racks (CASQA New
Development BMP Handbook SD-33)
No community wash racks onsite.
Water Quality Management Plan (WQMP)
4-7
4.1.2 Preventative LID Site Design Practices
Site design practices associated with new LID requirements in the MS4 Permit should be considered in the earliest
phases of a project. Preventative site design practices can result in smaller DCV for LID BMP and hydromodification
control BMP by reducing runoff generation. Describe site design and drainage plan including:
Refer to Section 5.2 of the TGD for WQMP for more details.
Form 4.1-3 Preventative LID Site Design Practices Checklist
Site Design Practices
If yes, explain how preventative site design practice is addressed in project site plan. If no, other LID BMPs must be selected to meet targets
Minimize impervious areas: Yes No
Explanation: Infiltration BMP will be used to infiltrate the design capture volume (DCV).
Maximize natural infiltration capacity: Yes No
Explanation: Infiltration system shall be designed with sufficient base surface areas that will drawdown the design capture
volume within 48-hrs. Unnecessary compaction of soil shall be minimized.
Preserve existing drainage patterns and time of concentration: Yes No
Explanation: Post-development drainage patterns will mimic pre-development conditions to the extent feasible. The
infiltration facilities will assist in maintaining the existing time of concentration.
Disconnect impervious areas: Yes No
Explanation:
Protect existing vegetation and sensitive areas: Yes No
Explanation: The project site is a developed site. No vegetation or sensitive areas to protect.
Re-vegetate disturbed areas: Yes No
Explanation: Not applicable, development consists of a light industrial facility. Most of the disturbed areas will be paved;
landscape will be provided throughout the site.
Minimize unnecessary compaction in stormwater retention/infiltration basin/trench areas: Yes No
Explanation: Heavy construction vehicles will be prohibited from unnecessary soil compaction around the infiltration facilities.
Utilize vegetated drainage swales in place of underground piping or imperviously lined swales: Yes No
Explanation: Underground piping is located underneath paved areas that could not be substituted with vegetated swales.
Stake off areas that will be used for landscaping to minimize compaction during construction : Yes No
Explanation: Where feasible, landscaped areas will be staked to minimize unnecessary compaction during construction.
A narrative of site design practices utilized or rationale for not using practices
A narrative of how site plan incorporates preventive site design practices
Include an attached Site Plan layout which shows how preventative site design practices are included in
WQMP
Water Quality Management Plan (WQMP)
4-8
4.2 Project Performance Criteria
The purpose of this section of the Project WQMP is to establish targets for post-development hydrology based on
performance criteria specified in the MS4 Permit. These targets include runoff volume for water quality control
(referred to as LID design capture volume), and runoff volume, time of concentration, and peak runoff for
protection of any downstream waterbody segments with a HCOC. If the project has more than one
outlet for stormwater runoff, then complete additional versions of these forms for each
DA / outlet.
Methods applied in the following forms include:
For LID BMP Design Capture Volume (DCV), the San Bernardino County Stormwater Program requires use of
the P6 method (MS4 Permit Section XI.D.6a.ii) – Form 4.2-1
For HCOC pre- and post-development hydrologic calculation, the San Bernardino County Stormwater Program
requires the use of the Rational Method (San Bernardino County Hydrology Manual Section D). Forms 4.2-2
through Form 4.2-5 calculate hydrologic variables including runoff volume, time of concentration, and peak
runoff from the project site pre- and post-development using the Hydrology Manual Rational Method approach.
For projects greater than 640 acres (1.0 mi2), the Rational Method and these forms should not be used. For such
projects, the Unit Hydrograph Method (San Bernardino County Hydrology Manual Section E) shall be applied
for hydrologic calculations for HCOC performance criteria.
Refer to Section 4 in the TGD for WQMP for detailed guidance and instructions.
Form 4.2-1 LID BMP Performance Criteria for Design Capture Volume
(DA 1)
1 Project area DA 1 (ft2):
358,070
2 Imperviousness after applying preventative
site design practices (Imp%): 88.5
3 Runoff Coefficient (Rc): 0.709
Rc = 0.858(Imp%)^3-0.78(Imp%)^2+0.774(Imp%)+0.04
4 Determine 1-hour rainfall depth for a 2-year return period P2yr-1hr (in): 0.533 http://hdsc.nws.noaa.gov/hdsc/pfds/sa/sca_pfds.html
5 Compute P6, Mean 6-hr Precipitation (inches): 0.79
P6 = Item 4 *C1, where C1 is a function of site climatic region specified in Form 3-1 Item 1 (Valley = 1.4807; Mountain = 1.909; Desert = 1.2371)
6 Drawdown Rate
Use 48 hours as the default condition. Selection and use of the 24 hour drawdown time condition is subject to approval
by the local jurisdiction. The necessary BMP footprint is a function of drawdown time. While shorter drawdown times
reduce the performance criteria for LID BMP design capture volume, the depth of water that can be stored is also
reduced.
24-hrs
48-hrs
7 Compute design capture volume, DCV (ft3): 32,766
DCV = 1/12 * [Item 1* Item 3 *Item 5 * C2], where C2 is a function of drawdown rate (24-hr = 1.582; 48-hr = 1.963)
Compute separate DCV for each outlet from the project site per schematic drawn in Form 3-1 Item 2
Water Quality Management Plan (WQMP)
4-9
Form 4.2-1 LID BMP Performance Criteria for Design Capture Volume
(DA 2)
1 Project area DA 1 (ft2):
332,956
2 Imperviousness after applying preventative
site design practices (Imp%): 88.4
3 Runoff Coefficient (Rc): 0.707
Rc = 0.858(Imp%)^3-0.78(Imp%)^2+0.774(Imp%)+0.04
4 Determine 1-hour rainfall depth for a 2-year return period P2yr-1hr (in): 0.533 http://hdsc.nws.noaa.gov/hdsc/pfds/sa/sca_pfds.html
5 Compute P6, Mean 6-hr Precipitation (inches): 0.79
P6 = Item 4 *C1, where C1 is a function of site climatic region specified in Form 3-1 Item 1 (Valley = 1.4807; Mountain = 1.909; Desert = 1.2371)
6 Drawdown Rate
Use 48 hours as the default condition. Selection and use of the 24 hour drawdown time condition is subject to approval
by the local jurisdiction. The necessary BMP footprint is a function of drawdown time. While shorter drawdown times
reduce the performance criteria for LID BMP design capture volume, the depth of water that can be stored is also
reduced.
24-hrs
48-hrs
7 Compute design capture volume, DCV (ft3): 30,393
DCV = 1/12 * [Item 1* Item 3 *Item 5 * C2], where C2 is a function of drawdown rate (24-hr = 1.582; 48-hr = 1.963)
Compute separate DCV for each outlet from the project site per schematic drawn in Form 3-1 Item 2
Form 4.2-2 Summary of HCOC Assessment (DA 1)
Does project have the potential to cause or contribute to an HCOC in a downstream channel: Yes No
Go to: http://permitrack.sbcounty.gov/wap/
If “Yes”, then complete HCOC assessment of site hydrology for 2yr storm event using Forms 4.2-3 through 4.2-5 and insert results below
(Forms 4.2-3 through 4.2-5 may be replaced by computer software analysis based on the San Bernardino County Hydrology Manual)
If “No,” then proceed to Section 4.3 Project Conformance Analysis
Condition Runoff Volume (ft3) Time of Concentration (min) Peak Runoff (cfs)
Pre-developed
1
Form 4.2-3 Item 12
2
Form 4.2-4 Item 13
3
Form 4.2-5 Item 10
Post-developed
4
Form 4.2-3 Item 13
5
Form 4.2-4 Item 14
6
Form 4.2-5 Item 14
Difference
7
Item 4 – Item 1
8
Item 2 – Item 5
9
Item 6 – Item 3
Difference
(as % of pre-developed)
10 %
Item 7 / Item 1
11 %
Item 8 / Item 2
12 %
Item 9 / Item 3
Water Quality Management Plan (WQMP)
4-10
Form 4.2-3 HCOC Assessment for Runoff Volume (DA 1)
Weighted Curve Number
Determination for:
Pre-developed DA
DMA A DMA B DMA C DMA D DMA E DMA F DMA G DMA H
1a Land Cover type
2a Hydrologic Soil Group (HSG)
3a DMA Area, ft2 sum of areas of
DMA should equal area of DA
4a Curve Number (CN) use Items
1 and 2 to select the appropriate CN
from Appendix C-2 of the TGD for
WQMP
Weighted Curve Number
Determination for:
Post-developed DA
DMA A DMA B DMA C DMA D DMA E DMA F DMA G DMA H
1b Land Cover type
2b Hydrologic Soil Group (HSG)
3b DMA Area, ft2 sum of areas of
DMA should equal area of DA
4b Curve Number (CN) use Items
5 and 6 to select the appropriate CN
from Appendix C-2 of the TGD for
WQMP
5 Pre-Developed area-weighted CN: 7 Pre-developed soil storage capacity, S (in):
S = (1000 / Item 5) - 10
9 Initial abstraction, Ia (in):
Ia = 0.2 * Item 7
6 Post-Developed area-weighted CN: 8 Post-developed soil storage capacity, S (in):
S = (1000 / Item 6) - 10
10 Initial abstraction, Ia (in):
Ia = 0.2 * Item 8
11 Precipitation for 2 yr, 24 hr storm (in):
Go to: http://hdsc.nws.noaa.gov/hdsc/pfds/sa/sca_pfds.html
12 Pre-developed Volume (ft3):
Vpre =(1 / 12) * (Item sum of Item 3) * [(Item 11 – Item 9)^2 / ((Item 11 – Item 9 + Item 7)
13 Post-developed Volume (ft3):
Vpre =(1 / 12) * (Item sum of Item 3) * [(Item 11 – Item 10)^2 / ((Item 11 – Item 10 + Item 8)
14 Volume Reduction needed to meet HCOC Requirement, (ft3):
VHCOC = (Item 13 * 0.95) – Item 12
Water Quality Management Plan (WQMP)
4-11
Form 4.2-4 HCOC Assessment for Time of Concentration (DA 1)
Compute time of concentration for pre and post developed conditions for each DA (For projects using the Hydrology Manual complete the
form below)
Variables
Pre-developed DA1
Use additional forms if there are more than 4 DMA
Post-developed DA1
Use additional forms if there are more than 4 DMA
DMA A DMA B DMA C DMA D DMA A DMA B DMA C DMA D
1 Length of flowpath (ft) Use Form 3-2
Item 5 for pre-developed condition
2 Change in elevation (ft)
3 Slope (ft/ft), So = Item 2 / Item 1
4 Land cover
5 Initial DMA Time of Concentration
(min) Appendix C-1 of the TGD for WQMP
6 Length of conveyance from DMA
outlet to project site outlet (ft)
May be zero if DMA outlet is at project
site outlet
7 Cross-sectional area of channel (ft2)
8 Wetted perimeter of channel (ft)
9 Manning’s roughness of channel (n)
10 Channel flow velocity (ft/sec)
Vfps = (1.49 / Item 9) * (Item 7/Item 8)^0.67
* (Item 3)^0.5
11 Travel time to outlet (min)
Tt = Item 6 / (Item 10 * 60)
12 Total time of concentration (min)
Tc = Item 5 + Item 11
13 Pre-developed time of concentration (min): Minimum of Item 12 pre-developed DMA
14 Post-developed time of concentration (min): Minimum of Item 12 post-developed DMA
15 Additional time of concentration needed to meet HCOC requirement (min): TC-HCOC = (Item 13 * 0.95) – Item 14
Water Quality Management Plan (WQMP)
4-12
Form 4.2-5 HCOC Assessment for Peak Runoff (DA 1)
Compute peak runoff for pre- and post-developed conditions
Variables
Pre-developed DA to Project
Outlet (Use additional forms if
more than 3 DMA)
Post-developed DA to Project
Outlet (Use additional forms if
more than 3 DMA)
DMA A DMA B DMA C DMA A DMA B DMA C
1 Rainfall Intensity for storm duration equal to time of concentration
Ipeak = 10^(LOG Form 4.2-1 Item 4 - 0.6 LOG Form 4.2-4 Item 5 /60)
2 Drainage Area of each DMA (Acres)
For DMA with outlet at project site outlet, include upstream DMA (Using example
schematic in Form 3-1, DMA A will include drainage from DMA C)
3 Ratio of pervious area to total area
For DMA with outlet at project site outlet, include upstream DMA (Using example
schematic in Form 3-1, DMA A will include drainage from DMA C)
4 Pervious area infiltration rate (in/hr)
Use pervious area CN and antecedent moisture condition with Appendix C-3 of the TGD
for WQMP
5 Maximum loss rate (in/hr)
Fm = Item 3 * Item 4
Use area-weighted Fm from DMA with outlet at project site outlet, include upstream
DMA (Using example schematic in Form 3-1, DMA A will include drainage from DMA C)
6 Peak Flow from DMA (cfs)
Qp =Item 2 * 0.9 * (Item 1 - Item 5)
7 Time of concentration adjustment factor for other DMA to
site discharge point
Form 4.2-4 Item 12 DMA / Other DMA upstream of site discharge
point (If ratio is greater than 1.0, then use maximum value of 1.0)
DMA A n/a n/a
DMA B n/a n/a
DMA C n/a n/a
8 Pre-developed Qp at Tc for DMA A:
Qp = Item 6DMAA + [Item 6DMAB * (Item 1DMAA - Item
5DMAB)/(Item 1DMAB - Item 5DMAB)* Item 7DMAA/2] +
[Item 6DMAC * (Item 1DMAA - Item 5DMAC)/(Item 1DMAC -
Item 5DMAC)* Item 7DMAA/3]
9 Pre-developed Qp at Tc for DMA B:
Qp = Item 6DMAB + [Item 6DMAA * (Item 1DMAB - Item
5DMAA)/(Item 1DMAA - Item 5DMAA)* Item 7DMAB/1] +
[Item 6DMAC * (Item 1DMAB - Item 5DMAC)/(Item 1DMAC -
Item 5DMAC)* Item 7DMAB/3]
10 Pre-developed Qp at Tc for DMA C:
Qp = Item 6DMAC + [Item 6DMAA * (Item 1DMAC - Item
5DMAA)/(Item 1DMAA - Item 5DMAA)* Item 7DMAC/1] +
[Item 6DMAB * (Item 1DMAC - Item 5DMAB)/(Item 1DMAB
- Item 5DMAB)* Item 7DMAC/2]
10 Peak runoff from pre-developed condition confluence analysis (cfs): Maximum of Item 8, 9, and 10 (including additional forms as needed)
11 Post-developed Qp at Tc for DMA A:
Same as Item 8 for post-developed values
12 Post-developed Qp at Tc for DMA B:
Same as Item 9 for post-developed values
13 Post-developed Qp at Tc for DMA C:
Same as Item 10 for post-developed
values
14 Peak runoff from post-developed condition confluence analysis (cfs): Maximum of Item 11, 12, and 13 (including additional forms as
needed)
15 Peak runoff reduction needed to meet HCOC Requirement (cfs): Qp-HCOC = (Item 14 * 0.95) – Item 10
Water Quality Management Plan (WQMP)
4-13
4.3 Project Conformance Analysis
Complete the following forms for each project site DA to document that the proposed LID BMPs conform to the
project DCV developed to meet performance criteria specified in the MS4 Permit (WQMP Template Section
4.2). For the LID DCV, the forms are ordered according to hierarchy of BMP selection as required by the MS4
Permit (see Section 5.3.1 in the TGD for WQMP). The forms compute the following for on-site LID BMP:
Site Design and Hydrologic Source Controls (Form 4.3-2)
Retention and Infiltration (Form 4.3-3)
Harvested and Use (Form 4.3-4) or
Biotreatment (Form 4.3-5).
At the end of each form, additional fields facilitate the determination of the extent of mitigation provided by
the specific BMP category, allowing for use of the next category of BMP in the hierarchy, if necessary.
The first step in the analysis, using Section 5.3.2.1 of the TGD for WQMP, is to complete Forms 4.3-1 and 4.3-3)
to determine if retention and infiltration BMPs are infeasible for the project. For each feasibility criterion in
Form 4.3-1, if the answer is “Yes,” provide all study findings that includes relevant calculations, maps, data
sources, etc. used to make the determination of infeasibility.
Next, complete Forms 4.3-2 and 4.3-4 to determine the feasibility of applicable HSC and harvest and use BMPs,
and, if their implementation is feasible, the extent of mitigation of the DCV.
If no site constraints exist that would limit the type of BMP to be implemented in a DA, evaluate the use of
combinations of LID BMPs, including all applicable HSC BMPs to maximize on-site retention of the DCV. If no
combination of BMP can mitigate the entire DCV, implement the single BMP type, or combination of BMP
types, that maximizes on-site retention of the DCV within the minimum effective area.
If the combination of LID HSC, retention and infiltration, and harvest and use BMPs are unable to mitigate the
entire DCV, then biotreatment BMPs may be implemented by the project proponent. If biotreatment BMPs are
used, then they must be sized to provide sufficient capacity for effective treatment of the remainder of the
volume-based performance criteria that cannot be achieved with LID BMPs (TGD for WQMP Section 5.4.4.2).
Under no circumstances shall any portion of the DCV be released from the site without effective
mitigation and/or treatment.
Water Quality Management Plan (WQMP)
4-14
Form 4.3-1 Infiltration BMP Feasibility (DA 1 and DA2)
Feasibility Criterion – Complete evaluation for each DA on the Project Site
1 Would infiltration BMP pose significant risk for groundwater related concerns? Yes No
Refer to Section 5.3.2.1 of the TGD for WQMP
If Yes, Provide basis: (attach)
2 Would installation of infiltration BMP significantly increase the risk of geotechnical hazards? Yes No
(Yes, if the answer to any of the following questions is yes, as established by a geotechnical expert):
The location is less than 50 feet away from slopes steeper than 15 percent
The location is less than eight feet from building foundations or an alternative setback.
A study certified by a geotechnical professional or an available watershed study determines that stormwater infiltration
would result in significantly increased risks of geotechnical hazards.
If Yes, Provide basis: (attach)
3 Would infiltration of runoff on a Project site violate downstream water rights? Yes No
If Yes, Provide basis: (attach)
4 Is proposed infiltration facility located on hydrologic soil group (HSG) D soils or does the site geotechnical investigation indicate
presence of soil characteristics, which support categorization as D soils? Yes No
If Yes, Provide basis: (attach)
5 Is the design infiltration rate, after accounting for safety factor of 2.0, below proposed facility less than 0.3 in/hr (accounting for
soil amendments)? Yes No
If Yes, Provide basis: (attach)
6 Would on-site infiltration or reduction of runoff over pre-developed conditions be partially or fully inconsistent with watershed
management strategies as defined in the WAP, or impair beneficial uses? Yes No
See Section 3.5 of the TGD for WQMP and WAP
If Yes, Provide basis: (attach)
7 Any answer from Item 1 through Item 3 is “Yes”: Yes No
If yes, infiltration of any volume is not feasible onsite. Proceed to Form 4.3-4, Harvest and Use BMP. If no, then proceed to Item 8
below.
8 Any answer from Item 4 through Item 6 is “Yes”: Yes No
If yes, infiltration is permissible but is not required to be considered. Proceed to Form 4.3-2, Hydrologic Source Control BMP.
If no, then proceed to Item 9, below.
9 All answers to Item 1 through Item 6 are “No”:
Infiltration of the full DCV is potentially feasible, LID infiltration BMP must be designed to infiltrate the full DCV to the MEP.
Proceed to Form 4.3-2, Hydrologic Source Control BMP.
Water Quality Management Plan (WQMP)
4-15
4.3.1 Site Design Hydrologic Source Control BMP
Section XI.E. of the Permit emphasizes the use of LID preventative measures; and the use of LID HSC BMPs
reduces the portion of the DCV that must be addressed in downstream BMPs. Therefore, all applicable HSC
shall be provided except where they are mutually exclusive with each other, or with other BMPs. Mutual
exclusivity may result from overlapping BMP footprints such that either would be potentially feasible by itself,
but both could not be implemented. Please note that while there are no numeric standards regarding the use of
HSC, if a project cannot feasibly meet BMP sizing requirements or cannot fully address HCOCs, feasibility of all
applicable HSC must be part of demonstrating that the BMP system has been designed to retain the maximum
feasible portion of the DCV. Complete Form 4.3-2 to identify and calculate estimated retention volume from
implementing site design HSC BMP. Refer to Section 5.4.1 in the TGD for more detailed guidance.
Form 4.3-2 Site Design Hydrologic Source Control BMPs (DA 1)
1 Implementation of Impervious Area Dispersion BMP (i.e.
routing runoff from impervious to pervious areas), excluding
impervious areas planned for routing to on-lot infiltration
BMP: Yes No If yes, complete Items 2-5; If no,
proceed to Item 6
DA 1 DMA A
BMP Type
Infiltration
Chamber
DA DMA
BMP Type
(Use additional forms
for more BMPs)
DA DMA
BMP Type
(Use additional forms
for more BMPs)
2 Total impervious area draining to pervious area (ft2) 316,873
3 Ratio of pervious area receiving runoff to impervious area 41,197/316,873 =
0.13
4 Retention volume achieved from impervious area
dispersion (ft3) V = Item2 * Item 3 * (0.5/12), assuming retention
of 0.5 inches of runoff
1,716
5 Sum of retention volume achieved from impervious area dispersion (ft3): Vretention =Sum of Item 4 for all BMPs
6 Implementation of Localized On-lot Infiltration BMPs (e.g.
on-lot rain gardens): Yes No If yes, complete Items 7-
13 for aggregate of all on-lot infiltration BMP in each DA; If no,
proceed to Item 14
DA DMA
BMP Type
DA DMA
BMP Type
DA DMA
BMP Type
(Use additional forms
for more BMPs)
7 Ponding surface area (ft2)
8 Ponding depth (ft)
9 Surface area of amended soil/gravel (ft2)
10 Average depth of amended soil/gravel (ft)
11 Average porosity of amended soil/gravel
12 Retention volume achieved from on-lot infiltration (ft3)
Vretention = (Item 7 *Item 8) + (Item 9 * Item 10 * Item 11)
Water Quality Management Plan (WQMP)
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13 Runoff volume retention from on-lot infiltration (ft3): Vretention =Sum of Item 12 for all BMPs
Form 4.3-2 cont. Site Design Hydrologic Source Control BMPs (DA 1)
14 Implementation of evapotranspiration BMP (green,
brown, or blue roofs): Yes No
If yes, complete Items 15-20. If no, proceed to Item 21
DA DMA
BMP Type
DA DMA
BMP Type
DA DMA
BMP Type
(Use additional forms
for more BMPs)
15 Rooftop area planned for ET BMP (ft2)
16 Average wet season ET demand (in/day)
Use local values, typical ~ 0.1
17 Daily ET demand (ft3/day)
Item 15 * (Item 16 / 12)
18 Drawdown time (hrs)
Copy Item 6 in Form 4.2-1
19 Retention Volume (ft3)
Vretention = Item 17 * (Item 18 / 24)
20 Runoff volume retention from evapotranspiration BMPs (ft3): Vretention =Sum of Item 19 for all BMPs
21 Implementation of Street Trees: Yes No
If yes, complete Items 22-25. If no, proceed to Item 26
DA DMA
BMP Type
DA DMA
BMP Type
DA DMA
BMP Type
(Use additional forms
for more BMPs)
22 Number of Street Trees
23 Average canopy cover over impervious area (ft2)
24 Runoff volume retention from street trees (ft3)
Vretention = Item 22 * Item 23 * (0.05/12) assume runoff retention of
0.05 inches
25 Runoff volume retention from street tree BMPs (ft3): Vretention = Sum of Item 24 for all BMPs
26 Implementation of residential rain barrel/cisterns: Yes
No If yes, complete Items 27-29; If no, proceed to Item 30
DA DMA
BMP Type
DA DMA
BMP Type
DA DMA
BMP Type
(Use additional forms
for more BMPs)
27 Number of rain barrels/cisterns
28 Runoff volume retention from rain barrels/cisterns (ft3)
Vretention = Item 27 * 3
29 Runoff volume retention from residential rain barrels/Cisterns (ft3): Vretention =Sum of Item 28 for all BMPs
Water Quality Management Plan (WQMP)
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30 Total Retention Volume from Site Design Hydrologic Source Control BMPs: 1,716 Sum of Items 5, 13, 20, 25 and 29
Form 4.3-2 Site Design Hydrologic Source Control BMPs (DA 2)
1 Implementation of Impervious Area Dispersion BMP (i.e.
routing runoff from impervious to pervious areas), excluding
impervious areas planned for routing to on-lot infiltration
BMP: Yes No If yes, complete Items 2-5; If no,
proceed to Item 6
DA 2 DMA B
BMP Type
Infiltration Chamber
DA DMA
BMP Type
(Use additional forms
for more BMPs)
DA DMA
BMP Type
(Use additional forms
for more BMPs)
2 Total impervious area draining to pervious area (ft2) 294,396
3 Ratio of pervious area receiving runoff to impervious area 38,560/294,396=
0.13
4 Retention volume achieved from impervious area
dispersion (ft3) V = Item2 * Item 3 * (0.5/12), assuming retention
of 0.5 inches of runoff
1,607
5 Sum of retention volume achieved from impervious area dispersion (ft3): Vretention =Sum of Item 4 for all BMPs
6 Implementation of Localized On-lot Infiltration BMPs (e.g.
on-lot rain gardens): Yes No If yes, complete Items 7-
13 for aggregate of all on-lot infiltration BMP in each DA; If no,
proceed to Item 14
DA DMA
BMP Type
DA DMA
BMP Type
DA DMA
BMP Type
(Use additional forms
for more BMPs)
7 Ponding surface area (ft2)
8 Ponding depth (ft)
9 Surface area of amended soil/gravel (ft2)
10 Average depth of amended soil/gravel (ft)
11 Average porosity of amended soil/gravel
12 Retention volume achieved from on-lot infiltration (ft3)
Vretention = (Item 7 *Item 8) + (Item 9 * Item 10 * Item 11)
13 Runoff volume retention from on-lot infiltration (ft3): Vretention =Sum of Item 12 for all BMPs
Form 4.3-2 cont. Site Design Hydrologic Source Control BMPs (DA2)
14 Implementation of evapotranspiration BMP (green,
brown, or blue roofs): Yes No
DA DMA
BMP Type
DA DMA
BMP Type DA DMA
Water Quality Management Plan (WQMP)
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If yes, complete Items 15-20. If no, proceed to Item 21 BMP Type
(Use additional forms
for more BMPs)
15 Rooftop area planned for ET BMP (ft2)
16 Average wet season ET demand (in/day)
Use local values, typical ~ 0.1
17 Daily ET demand (ft3/day)
Item 15 * (Item 16 / 12)
18 Drawdown time (hrs)
Copy Item 6 in Form 4.2-1
19 Retention Volume (ft3)
Vretention = Item 17 * (Item 18 / 24)
20 Runoff volume retention from evapotranspiration BMPs (ft3): Vretention =Sum of Item 19 for all BMPs
21 Implementation of Street Trees: Yes No
If yes, complete Items 22-25. If no, proceed to Item 26
DA DMA
BMP Type
DA DMA
BMP Type
DA DMA
BMP Type
(Use additional forms
for more BMPs)
22 Number of Street Trees
23 Average canopy cover over impervious area (ft2)
24 Runoff volume retention from street trees (ft3)
Vretention = Item 22 * Item 23 * (0.05/12) assume runoff retention of
0.05 inches
25 Runoff volume retention from street tree BMPs (ft3): Vretention = Sum of Item 24 for all BMPs
26 Implementation of residential rain barrel/cisterns: Yes
No If yes, complete Items 27-29; If no, proceed to Item 30
DA DMA
BMP Type
DA DMA
BMP Type
DA DMA
BMP Type
(Use additional forms
for more BMPs)
27 Number of rain barrels/cisterns
28 Runoff volume retention from rain barrels/cisterns (ft3)
Vretention = Item 27 * 3
29 Runoff volume retention from residential rain barrels/Cisterns (ft3): Vretention =Sum of Item 28 for all BMPs
30 Total Retention Volume from Site Design Hydrologic Source Control BMPs: 1,607 Sum of Items 5, 13, 20, 25 and 29
Water Quality Management Plan (WQMP)
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4.3.2 Infiltration BMPs
Use Form 4.3-3 to compute on-site retention of runoff from proposed retention and infiltration BMPs. Volume
retention estimates are sensitive to the percolation rate used, which determines the amount of runoff that can
be infiltrated within the specified drawdown time. The infiltration safety factor reduces field measured
percolation to account for potential inaccuracy associated with field measurements, declining BMP
performance over time, and compaction during construction. Appendix D of the TGD for WQMP provides
guidance on estimating an appropriate safety factor to use in Form 4.3-3.
If site constraints limit the use of BMPs to a single type and implementation of retention and infiltration BMPs
mitigate no more than 40% of the DCV, then they are considered infeasible and the Project Proponent may
evaluate the effectiveness of BMPs lower in the LID hierarchy of use (Section 5.5.1 of the TGD for WQMP)
If implementation of infiltrations BMPs is feasible as determined using Form 4.3-1, then LID infiltration BMPs
shall be implemented to the MEP (section 4.1 of the TGD for WQMP).
.
Water Quality Management Plan (WQMP)
4-20
Form 4.3-3 Infiltration LID BMP - including underground BMPs (DA 1)
1 Remaining LID DCV not met by site design HSC BMP (ft3): 31,050 Vunmet = Form 4.2-1 Item 7 - Form 4.3-2 Item 30
BMP Type Use columns to the right to compute runoff volume retention
from proposed infiltration BMP (select BMP from Table 5-4 in TGD for
WQMP) - Use additional forms for more BMPs
DA 1 DMA A
BMP Type
Infiltration
Chamber
DA DMA
BMP TYPE
DA DMA
BMP Type
(Use additional forms
for more BMPs)
2 Infiltration rate of underlying soils (in/hr) See Section 5.4.2 and
Appendix D of the TGD for WQMP for minimum requirements for
assessment methods
15.9
3 Infiltration safety factor See TGD Section 5.4.2 and Appendix D 2
4 Design percolation rate (in/hr) Pdesign = Item 2 / Item 3 7.95
5 Ponded water drawdown time (hr) Copy Item 6 in Form 4.2-1 48
6 Maximum ponding depth (ft) BMP specific, see Table 5-4 of the TGD
for WQMP for BMP design details
5
7 Ponding Depth (ft) dBMP = Minimum of (1/12*Item 4*Item 5) or Item 6 5
8 Infiltrating surface area, SABMP (ft2) the lesser of the area needed for
infiltration of full DCV or minimum space requirements from Table 5.7 of
the TGD for WQMP
4,689
9 Amended soil depth, dmedia (ft) Only included in certain BMP types,
see Table 5-4 in the TGD for WQMP for reference to BMP design details
N/A
10 Amended soil porosity N/A
11 Gravel depth, dmedia (ft) Only included in certain BMP types, see
Table 5-4 of the TGD for WQMP for BMP design details
1.75
12 Gravel porosity 0.4
13 Duration of storm as basin is filling (hrs) Typical ~ 3hrs 3
14 Above Ground Retention Volume (ft3) Vretention = Item 8 * [Item7 +
(Item 9 * Item 10) + (Item 11 * Item 12) + (Item 13 * (Item 4 / 12))]
0
15 Underground Retention Volume (ft3) Volume determined using
manufacturer’s specifications and calculations
55,818
16 Total Retention Volume from LID Infiltration BMPs: 55,818 (Sum of Items 14 and 15 for all infiltration BMP included in plan)
17 Fraction of DCV achieved with infiltration BMP: 100% Retention% = Item 16 / Form 4.2-1 Item 7
18 Is full LID DCV retained onsite with combination of hydrologic source control and LID retention/infiltration BMPs? Yes No
If yes, demonstrate conformance using Form 4.3-10; If no, then reduce Item 3, Factor of Safety to 2.0 and increase Item 8, Infiltrating Surface Area, such that
the portion of the site area used for retention and infiltration BMPs equals or exceeds the minimum effective area thresholds (Table 5-7 of the TGD for WQMP)
for the applicable category of development and repeat all above calculations.
Water Quality Management Plan (WQMP)
4-21
Form 4.3-3 Infiltration LID BMP - including underground BMPs (DA2)
1 Remaining LID DCV not met by site design HSC BMP (ft3): 28,786 Vunmet = Form 4.2-1 Item 7 - Form 4.3-2 Item 30
BMP Type Use columns to the right to compute runoff volume retention
from proposed infiltration BMP (select BMP from Table 5-4 in TGD for
WQMP) - Use additional forms for more BMPs
DA 2 DMA B
BMP Type
Infiltration
Chamber
DA DMA
BMP TYPE
DA DMA
BMP Type
(Use additional forms
for more BMPs)
2 Infiltration rate of underlying soils (in/hr) See Section 5.4.2 and
Appendix D of the TGD for WQMP for minimum requirements for
assessment methods
15.9
3 Infiltration safety factor See TGD Section 5.4.2 and Appendix D 2
4 Design percolation rate (in/hr) Pdesign = Item 2 / Item 3 7.95
5 Ponded water drawdown time (hr) Copy Item 6 in Form 4.2-1 48
6 Maximum ponding depth (ft) BMP specific, see Table 5-4 of the TGD
for WQMP for BMP design details
5
7 Ponding Depth (ft) dBMP = Minimum of (1/12*Item 4*Item 5) or Item 6 5
8 Infiltrating surface area, SABMP (ft2) the lesser of the area needed for
infiltration of full DCV or minimum space requirements from Table 5.7 of
the TGD for WQMP
4,350
9 Amended soil depth, dmedia (ft) Only included in certain BMP types,
see Table 5-4 in the TGD for WQMP for reference to BMP design details
N/A
10 Amended soil porosity N/A
11 Gravel depth, dmedia (ft) Only included in certain BMP types, see
Table 5-4 of the TGD for WQMP for BMP design details
1.75
12 Gravel porosity 0.4
13 Duration of storm as basin is filling (hrs) Typical ~ 3hrs 3
14 Above Ground Retention Volume (ft3) Vretention = Item 8 * [Item7 +
(Item 9 * Item 10) + (Item 11 * Item 12) + (Item 13 * (Item 4 / 12))]
0
15 Underground Retention Volume (ft3) Volume determined using
manufacturer’s specifications and calculations
55,818
16 Total Retention Volume from LID Infiltration BMPs: 55,818 (Sum of Items 14 and 15 for all infiltration BMP included in plan)
17 Fraction of DCV achieved with infiltration BMP: 100% Retention% = Item 16 / Form 4.2-1 Item 7
18 Is full LID DCV retained onsite with combination of hydrologic source control and LID retention/infiltration BMPs? Yes No
If yes, demonstrate conformance using Form 4.3-10; If no, then reduce Item 3, Factor of Safety to 2.0 and increase Item 8, Infiltrating Surface Area, such that
the portion of the site area used for retention and infiltration BMPs equals or exceeds the minimum effective area thresholds (Table 5-7 of the TGD for WQMP)
for the applicable category of development and repeat all above calculations.
Water Quality Management Plan (WQMP)
4-22
4.3.3 Harvest and Use BMP
Harvest and use BMP may be considered if the full LID DCV cannot be met by maximizing infiltration BMPs.
Use Form 4.3-4 to compute on-site retention of runoff from proposed harvest and use BMPs.
Volume retention estimates for harvest and use BMPs are sensitive to the on-site demand for captured
stormwater. Since irrigation water demand is low in the wet season, when most rainfall events occur in San
Bernardino County, the volume of water that can be used within a specified drawdown period is relatively low.
The bottom portion of Form 4.3-4 facilitates the necessary computations to show infeasibility if a minimum
incremental benefit of 40 percent of the LID DCV would not be achievable with MEP implementation of on-site
harvest and use of stormwater (Section 5.5.4 of the TGD for WQMP).
Form 4.3-4 Harvest and Use BMPs (DA 1)
1 Remaining LID DCV not met by site design HSC or infiltration BMP (ft3):
Vunmet = Form 4.2-1 Item 7 - Form 4.3-2 Item 30 – Form 4.3-3 Item 16
BMP Type(s) Compute runoff volume retention from proposed
harvest and use BMP (Select BMPs from Table 5-4 of the TGD for
WQMP) - Use additional forms for more BMPs
DA DMA
BMP Type
DA DMA
BMP Type
DA DMA
BMP Type
(Use additional forms
for more BMPs)
2 Describe cistern or runoff detention facility
3 Storage volume for proposed detention type (ft3) Volume of
cistern
4 Landscaped area planned for use of harvested stormwater
(ft2)
5 Average wet season daily irrigation demand (in/day)
Use local values, typical ~ 0.1 in/day
6 Daily water demand (ft3/day) Item 4 * (Item 5 / 12)
7 Drawdown time (hrs) Copy Item 6 from Form 4.2-1
8Retention Volume (ft3)
Vretention = Minimum of (Item 3) or (Item 6 * (Item 7 / 24))
9 Total Retention Volume (ft3) from Harvest and Use BMP Sum of Item 8 for all harvest and use BMP included in plan
10 Is the full DCV retained with a combination of LID HSC, retention and infiltration, and harvest & use BMPs? Yes No
If yes, demonstrate conformance using Form 4.3-10. If no, then re-evaluate combinations of all LID BMP and optimize their implementation
such that the maximum portion of the DCV is retained on-site (using a single BMP type or combination of BMP types). If the full DCV cannot
be mitigated after this optimization process, proceed to Section 4.3.4.
Water Quality Management Plan (WQMP)
4-23
4.3.4 Biotreatment BMP
Biotreatment BMPs may be considered if the full LID DCV cannot be met by maximizing retention and
infiltration, and harvest and use BMPs. A key consideration when using biotreatment BMP is the effectiveness
of the proposed BMP in addressing the pollutants of concern for the project (see Table 5-5 of the TGD for
WQMP).
Use Form 4.3-5 to summarize the potential for volume based and/or flow based biotreatment options to
biotreat the remaining unmet LID DCV w. Biotreatment computations are included as follows:
Use Form 4.3-6 to compute biotreatment in small volume based biotreatment BMP (e.g. bioretention w/underdrains);
Use Form 4.3-7 to compute biotreatment in large volume based biotreatment BMP (e.g. constructed wetlands);
Use Form 4.3-8 to compute sizing criteria for flow-based biotreatment BMP (e.g. bioswales)
Form 4.3-5 Selection and Evaluation of Biotreatment BMP (DA 1)
1 Remaining LID DCV not met by site design HSC,
infiltration, or harvest and use BMP for potential
biotreatment (ft3): Form 4.2-1 Item 7 - Form 4.3-2
Item 30 – Form 4.3-3 Item 16- Form 4.3-4 Item 9
List pollutants of concern Copy from Form 2.3-1.
2 Biotreatment BMP Selected
(Select biotreatment BMP(s)
necessary to ensure all pollutants of
concern are addressed through Unit
Operations and Processes, described
in Table 5-5 of the TGD for WQMP)
Volume-based biotreatment
Use Forms 4.3-6 and 4.3-7 to compute treated volume
Flow-based biotreatment
Use Form 4.3-8 to compute treated volume
Bioretention with underdrain
Planter box with underdrain
Constructed wetlands
Wet extended detention
Dry extended detention
Vegetated swale
Vegetated filter strip
Proprietary biotreatment
3 Volume biotreated in volume based
biotreatment BMP (ft3): Form 4.3-
6 Item 15 + Form 4.3-7 Item 13
4 Compute remaining LID DCV with
implementation of volume based biotreatment
BMP (ft3): Item 1 – Item 3
5 Remaining fraction of LID DCV for
sizing flow based biotreatment BMP:
% Item 4 / Item 1
6 Flow-based biotreatment BMP capacity provided (cfs): Use Figure 5-2 of the TGD for WQMP to determine flow capacity required to
provide biotreatment of remaining percentage of unmet LID DCV (Item 5), for the project’s precipitation zone (Form 3-1 Item 1)
7 Metrics for MEP determination:
Provided a WQMP with the portion of site area used for suite of LID BMP equal to minimum thresholds in Table 5-7 of the
TGD for WQMP for the proposed category of development: If maximized on-site retention BMPs is feasible for partial capture,
then LID BMP implementation must be optimized to retain and infiltrate the maximum portion of the DCV possible within the prescribed
minimum effective area. The remaining portion of the DCV shall then be mitigated using biotreatment BMP.
Water Quality Management Plan (WQMP)
4-24
Form 4.3-6 Volume Based Biotreatment (DA 1) –
Bioretention and Planter Boxes with Underdrains
Biotreatment BMP Type
(Bioretention w/underdrain, planter box w/underdrain, other
comparable BMP)
DA DMA
BMP Type
DA DMA
BMP Type
DA DMA
BMP Type
(Use additional forms
for more BMPs)
1 Pollutants addressed with BMP List all pollutant of concern that
will be effectively reduced through specific Unit Operations and
Processes described in Table 5-5 of the TGD for WQMP
2 Amended soil infiltration rate Typical ~ 5.0
3 Amended soil infiltration safety factor Typical ~ 2.0
4 Amended soil design percolation rate (in/hr) Pdesign = Item 2 /
Item 3
5 Ponded water drawdown time (hr) Copy Item 6 from Form 4.2-1
6 Maximum ponding depth (ft) see Table 5-6 of the TGD for WQMP
for reference to BMP design details
7 Ponding Depth (ft) dBMP = Minimum of (1/12 * Item 4 * Item 5) or
Item 6
8 Amended soil surface area (ft2)
9 Amended soil depth (ft) see Table 5-6 of the TGD for WQMP for
reference to BMP design details
10 Amended soil porosity, n
11 Gravel depth (ft) see Table 5-6 of the TGD for WQMP for reference
to BMP design details
12 Gravel porosity, n
13 Duration of storm as basin is filling (hrs) Typical ~ 3hrs
14 Biotreated Volume (ft3) Vbiotreated = Item 8 * [(Item 7/2) + (Item 9
* Item 10) +(Item 11 * Item 12) + (Item 13 * (Item 4 / 12))]
15 Total biotreated volume from bioretention and/or planter box with underdrains BMP:
Sum of Item 14 for all volume-based BMPs included in this form
Water Quality Management Plan (WQMP)
4-25
Form 4.3-7 Volume Based Biotreatment (DA 1) –
Constructed Wetlands and Extended Detention
Biotreatment BMP Type
Constructed wetlands, extended wet detention, extended dry detention,
or other comparable proprietary BMP. If BMP includes multiple modules
(e.g. forebay and main basin), provide separate estimates for storage
and pollutants treated in each module.
DA DMA
BMP Type
DA DMA
BMP Type
(Use additional forms
for more BMPs)
Forebay Basin Forebay Basin
1 Pollutants addressed with BMP forebay and basin
List all pollutant of concern that will be effectively reduced through
specific Unit Operations and Processes described in Table 5-5 of the TGD
for WQMP
2 Bottom width (ft)
3 Bottom length (ft)
4 Bottom area (ft2) Abottom = Item 2 * Item 3
5 Side slope (ft/ft)
6 Depth of storage (ft)
7 Water surface area (ft2)
Asurface =(Item 2 + (2 * Item 5 * Item 6)) * (Item 3 + (2 * Item 5 * Item 6))
8 Storage volume (ft3) For BMP with a forebay, ensure fraction of
total storage is within ranges specified in BMP specific fact sheets, see
Table 5-6 of the TGD for WQMP for reference to BMP design details
V =Item 6 / 3 * [Item 4 + Item 7 + (Item 4 * Item 7)^0.5]
9 Drawdown Time (hrs) Copy Item 6 from Form 2.1
10 Outflow rate (cfs) QBMP = (Item 8forebay + Item 8basin) / (Item 9 * 3600)
11 Duration of design storm event (hrs)
12 Biotreated Volume (ft3)
Vbiotreated = (Item 8forebay + Item 8basin) +( Item 10 * Item 11 * 3600)
13 Total biotreated volume from constructed wetlands, extended dry detention, or extended wet detention :
(Sum of Item 12 for all BMP included in plan)
Water Quality Management Plan (WQMP)
4-26
Form 4.3-8 Flow Based Biotreatment (DA 1)
Biotreatment BMP Type
Vegetated swale, vegetated filter strip, or other comparable proprietary
BMP
DA DMA
BMP Type
DA DMA
BMP Type
DA DMA
BMP Type
(Use additional forms
for more BMPs)
1 Pollutants addressed with BMP
List all pollutant of concern that will be effectively reduced through
specific Unit Operations and Processes described in TGD Table 5-5
2 Flow depth for water quality treatment (ft)
BMP specific, see Table 5-6 of the TGD for WQMP for reference to BMP
design details
3 Bed slope (ft/ft)
BMP specific, see Table 5-6 of the TGD for WQMP for reference to BMP
design details
4 Manning's roughness coefficient
5 Bottom width (ft)
bw = (Form 4.3-5 Item 6 * Item 4) / (1.49 * Item 2^1.67 * Item 3^0.5)
6 Side Slope (ft/ft)
BMP specific, see Table 5-6 of the TGD for WQMP for reference to BMP
design details
7 Cross sectional area (ft2)
A = (Item 5 * Item 2) + (Item 6 * Item 2^2)
8 Water quality flow velocity (ft/sec)
V = Form 4.3-5 Item 6 / Item 7
9 Hydraulic residence time (min)
Pollutant specific, see Table 5-6 of the TGD for WQMP for reference to
BMP design details
10 Length of flow based BMP (ft)
L = Item 8 * Item 9 * 60
11 Water surface area at water quality flow depth (ft2)
SAtop = (Item 5 + (2 * Item 2 * Item 6)) * Item 10
Water Quality Management Plan (WQMP)
4-27
4.3.5 Conformance Summary
Complete Form 4.3-9 to demonstrate how on-site LID DCV is met with proposed site design hydrologic source
control, infiltration, harvest and use, and/or biotreatment BMP. The bottom line of the form is used to describe
the basis for infeasibility determination for on-site LID BMP to achieve full LID DCV, and provides methods for
computing remaining volume to be addressed in an alternative compliance plan. If the project has more than
one outlet, then complete additional versions of this form for each outlet.
Form 4.3-9 Conformance Summary and Alternative
Compliance Volume Estimate (DA 1)
1 Total LID DCV for the Project DA-1 (ft3): 32,766 Copy Item 7 in Form 4.2-1
2 On-site retention with site design hydrologic source control LID BMP (ft3): 1,716 Copy Item 30 in Form 4.3-2
3 On-site retention with LID infiltration BMP (ft3): 55,818 Copy Item 16 in Form 4.3-3
4 On-site retention with LID harvest and use BMP (ft3): 0 Copy Item 9 in Form 4.3-4
5 On-site biotreatment with volume based biotreatment BMP (ft3): 0 Copy Item 3 in Form 4.3-5
6 Flow capacity provided by flow based biotreatment BMP (cfs): 0 Copy Item 6 in Form 4.3-5
7 LID BMP performance criteria are achieved if answer to any of the following is “Yes”:
Full retention of LID DCV with site design HSC, infiltration, or harvest and use BMP: Yes No
If yes, sum of Items 2, 3, and 4 is greater than Item 1
Combination of on-site retention BMPs for a portion of the LID DCV and volume-based biotreatment BMP that
address all pollutants of concern for the remaining LID DCV: Yes No
If yes, a) sum of Items 2, 3, 4, and 5 is greater than Item 1, and Items 2, 3 and 4 are maximized; or b) Item 6 is greater than Form
4.3--5 Item 6 and Items 2, 3 and 4 are maximized
On-site retention and infiltration is determined to be infeasible and biotreatment BMP provide biotreatment for all
pollutants of concern for full LID DCV: Yes No
If yes, Form 4.3-1 Items 7 and 8 were both checked yes
8 If the LID DCV is not achieved by any of these means, then the project may be allowed to develop an alternative
compliance plan. Check box that describes the scenario which caused the need for alternative compliance:
Combination of HSC, retention and infiltration, harvest and use, and biotreatment BMPs provide less than full LID DCV
capture:
Checked yes for Form 4.3-5 Item 7, Item 6 is zero, and sum of Items 2, 3, 4, and 5 is less than Item 1. If so, apply water quality credits
and calculate volume for alternative compliance, Valt = (Item 1 – Item 2 – Item 3 – Item 4 – Item 5) * (100 - Form 2.4-1 Item 2)%
An approved Watershed Action Plan (WAP) demonstrates that water quality and hydrologic impacts of urbanization
are more effective when managed in at an off-site facility:
Attach appropriate WAP section, including technical documentation, showing effectiveness comparisons for the project site and
regional watershed
Water Quality Management Plan (WQMP)
4-28
Form 4.3-9 Conformance Summary and Alternative
Compliance Volume Estimate (DA 2)
1 Total LID DCV for the Project DA-1 (ft3): 30,393 Copy Item 7 in Form 4.2-1
2 On-site retention with site design hydrologic source control LID BMP (ft3): 1,607 Copy Item 30 in Form 4.3-2
3 On-site retention with LID infiltration BMP (ft3): 55,818 Copy Item 16 in Form 4.3-3
4 On-site retention with LID harvest and use BMP (ft3): 0 Copy Item 9 in Form 4.3-4
5 On-site biotreatment with volume based biotreatment BMP (ft3): 0 Copy Item 3 in Form 4.3-5
6 Flow capacity provided by flow based biotreatment BMP (cfs): 0 Copy Item 6 in Form 4.3-5
7 LID BMP performance criteria are achieved if answer to any of the following is “Yes”:
Full retention of LID DCV with site design HSC, infiltration, or harvest and use BMP: Yes No
If yes, sum of Items 2, 3, and 4 is greater than Item 1
Combination of on-site retention BMPs for a portion of the LID DCV and volume-based biotreatment BMP that
address all pollutants of concern for the remaining LID DCV: Yes No
If yes, a) sum of Items 2, 3, 4, and 5 is greater than Item 1, and Items 2, 3 and 4 are maximized; or b) Item 6 is greater than Form
4.3--5 Item 6 and Items 2, 3 and 4 are maximized
On-site retention and infiltration is determined to be infeasible and biotreatment BMP provide biotreatment for all
pollutants of concern for full LID DCV: Yes No
If yes, Form 4.3-1 Items 7 and 8 were both checked yes
8 If the LID DCV is not achieved by any of these means, then the project may be allowed to develop an alternative
compliance plan. Check box that describes the scenario which caused the need for alternative compliance:
Combination of HSC, retention and infiltration, harvest and use, and biotreatment BMPs provide less than full LID DCV
capture:
Checked yes for Form 4.3-5 Item 7, Item 6 is zero, and sum of Items 2, 3, 4, and 5 is less than Item 1. If so, apply water quality credits
and calculate volume for alternative compliance, Valt = (Item 1 – Item 2 – Item 3 – Item 4 – Item 5) * (100 - Form 2.4-1 Item 2)%
An approved Watershed Action Plan (WAP) demonstrates that water quality and hydrologic impacts of urbanization
are more effective when managed in at an off-site facility:
Attach appropriate WAP section, including technical documentation, showing effectiveness comparisons for the project site and
regional watershed
Water Quality Management Plan (WQMP)
4-29
4.3.6 Hydromodification Control BMP
Use Form 4.3-10 to compute the remaining runoff volume retention, after LID BMP are implemented, needed to
address HCOC, and the increase in time of concentration and decrease in peak runoff necessary to meet targets
for protection of waterbodies with a potential HCOC. Describe hydromodification control BMP that address
HCOC, which may include off-site BMP and/or in-stream controls. Section 5.6 of the TGD for WQMP provides
additional details on selection and evaluation of hydromodification control BMP.
Form 4.3-10 Hydromodification Control BMPs (DA 1)
1 Volume reduction needed for HCOC
performance criteria (ft3):
(Form 4.2-2 Item 4 * 0.95) – Form 4.2-2 Item 1
2 On-site retention with site design hydrologic source control, infiltration, and
harvest and use LID BMP (ft3): Sum of Form 4.3-9 Items 2, 3, and 4 Evaluate
option to increase implementation of on-site retention in Forms 4.3-2, 4.3-3, and 4.3-4 in
excess of LID DCV toward achieving HCOC volume reduction
3 Remaining volume for HCOC
volume capture (ft3): Item 1 –
Item 2
4 Volume capture provided by incorporating additional on-site or off-site retention BMPs
(ft3): Existing downstream BMP may be used to demonstrate additional volume capture (if
so, attach to this WQMP a hydrologic analysis showing how the additional volume would be retained
during a 2-yr storm event for the regional watershed)
5 If Item 4 is less than Item 3, incorporate in-stream controls on downstream waterbody segment to prevent impacts due to
hydromodification Attach in-stream control BMP selection and evaluation to this WQMP
6 Is Form 4.2-2 Item 11 less than or equal to 5%: Yes No
If yes, HCOC performance criteria is achieved. If no, select one or more mitigation options below:
Demonstrate increase in time of concentration achieved by proposed LID site design, LID BMP, and additional on-site
or off-site retention BMP
BMP upstream of a waterbody segment with a potential HCOC may be used to demonstrate increased time of concentration through
hydrograph attenuation (if so, show that the hydraulic residence time provided in BMP for a 2-year storm event is equal or greater
than the addition time of concentration requirement in Form 4.2-4 Item 15)
Increase time of concentration by preserving pre-developed flow path and/or increase travel time by reducing slope
and increasing cross-sectional area and roughness for proposed on-site conveyance facilities
Incorporate appropriate in-stream controls for downstream waterbody segment to prevent impacts due to
hydromodification, in a plan approved and signed by a licensed engineer in the State of California
7 Form 4.2-2 Item 12 less than or equal to 5%: Yes No
If yes, HCOC performance criteria is achieved. If no, select one or more mitigation options below:
Demonstrate reduction in peak runoff achieved by proposed LID site design, LID BMPs, and additional on-site or off-
site retention BMPs
BMPs upstream of a waterbody segment with a potential HCOC may be used to demonstrate additional peak runoff reduction
through hydrograph attenuation (if so, attach to this WQMP, a hydrograph analysis showing how the peak runoff would be reduced
during a 2-yr storm event)
Incorporate appropriate in-stream controls for downstream waterbody segment to prevent impacts due to
hydromodification, in a plan approved and signed by a licensed engineer in the State of California
Water Quality Management Plan (WQMP)
4-30
4.4 Alternative Compliance Plan (if applicable)
Describe an alternative compliance plan (if applicable) for projects not fully able to infiltrate, harvest and use,
or biotreat the DCV via on-site LID practices. A project proponent must develop an alternative compliance plan
to address the remainder of the LID DCV. Depending on project type some projects may qualify for water
quality credits that can be applied to reduce the DCV that must be treated prior to development of an
alternative compliance plan (see Form 2.4-1, Water Quality Credits). Form 4.3-9 Item 8 includes instructions on
how to apply water quality credits when computing the DCV that must be met through alternative compliance.
Alternative compliance plans may include one or more of the following elements:
On-site structural treatment control BMP - All treatment control BMP should be located as close to
possible to the pollutant sources and should not be located within receiving waters;
Off-site structural treatment control BMP - Pollutant removal should occur prior to discharge of runoff to
receiving waters;
Urban runoff fund or In-lieu program, if available
Depending upon the proposed alternative compliance plan, approval by the executive officer may or may not be
required (see Section 6 of the TGD for WQMP).
Water Quality Management Plan (WQMP)
5-1
Section 5 Inspection and Maintenance Responsibility
for Post Construction BMP
All BMP included as part of the project WQMP are required to be maintained through regular scheduled
inspection and maintenance (refer to Section 8, Post Construction BMP Requirements, in the TGD for WQMP).
Fully complete Form 5-1 summarizing all BMP included in the WQMP. Attach additional forms as needed. The
WQMP shall also include a detailed Operation and Maintenance Plan for all BMP and may require a
Maintenance Agreement (consult the jurisdiction’s LIP). If a Maintenance Agreement is required, it must also
be attached to the WQMP.
Form 5-1 BMP Inspection and Maintenance
(use additional forms as necessary)
BMP Reponsible Party(s) Inspection/ Maintenance
Activities Required
Minimum Frequency
of Activities
Water Quality Management Plan (WQMP)
6-1
Section 6 WQMP Attachments
6.1. Site Plan and Drainage Plan
Include a site plan and drainage plan sheet set containing the following minimum information:
6.2 Electronic Data Submittal
Minimum requirements include submittal of PDF exhibits in addition to hard copies. Format must not require
specialized software to open. If the local jurisdiction requires specialized electronic document formats (as
described in their local Local Implementation Plan), this section will describe the contents (e.g., layering,
nomenclature, geo-referencing, etc.) of these documents so that they may be interpreted efficiently and
accurately.
6.3 Post Construction
Attach all O&M Plans and Maintenance Agreements for BMP to the WQMP.
6.4 Other Supporting Documentation
BMP Educational Materials
Activity Restriction – C, C&R’s & Lease Agreements
Project location
Site boundary
Land uses and land covers, as applicable
Suitability/feasibility constraints
Structural Source Control BMP locations
Site Design Hydrologic Source Control BMP locations
LID BMP details
Drainage delineations and flow information
Drainage connections
Water Quality Management Plan (WQMP)
6-2
6.1. Site Plan and Drainage Plan
Water Quality Management Plan (WQMP)
6-3
6.2. Electronic Data Submittal
Water Quality Management Plan (WQMP)
6-4
6.3. Post Construction
Attached is all O&M Plans and Maintenance Agreements for BMP to the WQMP.
Water Quality Management Plan (WQMP)
6-5
6.4. Other Supporting Documentation
Water Quality Management Plan (WQMP)
6-6
6.4.1 Vicinity Map
Water Quality Management Plan (WQMP)
6-7
6.4.2 Treatment BMP Factsheet
Water Quality Management Plan (WQMP)
6-8
6.4.3 Manufacturer’s Specification and Details
Water Quality Management Plan (WQMP)
6-9
6.4.4 NOAA Atlas 14 Rainfall Data
2.0
/
Water Quality Management Plan (WQMP)
6-10
6.4.5 Factor of Safety Worksheet