HomeMy WebLinkAboutMS 2019-0003; BMW OF CARLSBAD; PRIORITY DEVELOPMENT PROJECT (PDP) STORM WATER QUALITY MANAGEMENT PLAN (SWQMP); 2021-05-24ENGINEER OF WORK:
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PRIORITY DEVELOPMENT PROJECT (PDP)
STORM WATER QUALITY MANAGEMENT PLAN (SWQMP)
FOR
BMW OF CARLSBAD
1060 Auto Center Court
Carlsbad, CA 92008
CDP2019-001 3, DEV20 18-0198, MS2019-0003
SWQMP No. TBD
Aaron M. Albertson, RCE 65513, Exp. 09/30/21
(Provide Wet Signature and Stamp Above Line)
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NO. 65513 zirn
EXP. /3O/21 I
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PREPARED FOR:
AutoNation Inc.
200 SW 1st Ave, 14th Floor
Fort Lauderdale, FL 33301
TEL: (954) 769-6000
PREPARED BY:
Cr—
Commercial
DeWopmert
Resources
Today's Ideas. Tomorrows Reality.
4121 Westerly Place, Suite 112
Newport Beach, CA 92660
TEL: (949) 610-8997
DATE:
May 24th, 2021
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LAND DEVELOPMEN IM ENGINEERING (.)
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Priority Development Project (POP) SWQMP
BMW of Carlsbad
TABLE OF CONTENTS
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PDPSWQMP
CertificationPage ... ............. ................. ............ ............................................ .. ............ 2
Project Vicinity Map...................................................................................................3
FORM E-34: Storm Water Standard Questionnaire...........................................................4
SiteInformation ................. ......... .... . ...................... ......................... ........................... 5
FORM E-36: Standard Project Requirement Checklist......................................................13
Summary of PDP Structural BMPs..............................................................................14
Attachment 1: Backup for PDP Pollutant Control BMPs....................................................21
Attachment la: DMA Exhibit
Attachment I b: DMA Summary
Attachment Ic: Harvest and Use Feasibility Screening
Attachment Id: Categorization of Infiltration Feasibility Condition (Form 1-8)
Attachment le: Pollutant Control BMP Design Worksheets / Calculations
LID DCV Calculation Summary
San Diego County 851h Percentile Isopluvial Map
Workseet B.5-I: Simple Sizing Method for Biofiltration BMPs (x4)
Worksneet B.4-1: Simple Sizing Method for Infiltration BMPs
Works-heet B.6-1: Flow-Thru Design Flows
BMP Sizing & Detail Sheets
Attachment 2: Backup for PDP Hydromodification Control Measures ....... ............................ 23
Attachment 2a: Hydromodification Management Exhibit
Attachment 2b: Management of Critical Coarse Sediment Yield Areas (WMAA Exhibit)
Attachment 2c: Not Included
Attachment 2d: Flow Control Facility Design
Attachment 3: Structural BMP Maintenance Information....................................................25
Attachment 4: Single Sheet BMP (SSBMP) Exhibit .................. ............................ ............ 28
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Priority Development Project (PDP) SWQMP cwvblkqn~
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BMW of Carlsbad alfts=cas
CERTIFICATION PAGE
Project Name: BMW of Carlsbad
Project ID: MS2019-0003/CDP20I9-0013
I hereby declare that I am the Engineer in Responsible Charge of design of storm water BMPs for
this project, and that I have exercised responsible charge over the design of the project as defined
in Section 6703 of the Business and Professions Code, and that the design is consistent with the
requirements of the BMP Design Manual, which is based on the requirements of SDRWQCB
Order No. R9-2013-0001 (MS4 Permit) or the current Order.
I have read and understand that the City Engineer has adopted minimum requirements for
managing urban runoff, including storm water, from land development activities, as described in
the BMP Design Manual. I certify that this SWQMP has been completed to the best of my ability
and accurately reflects the project being proposed and the applicable source control and site
design BMPs proposed to minimize the potentially negative impacts of this project's land
development activities on water quality. I understand and acknowledge that the plan check review
of this SWQMP by the City Engineer is confined to a review and does not relieve me, as the
Engineer in Responsible Charge of design of storm water BMPs for this project, of my
responsibilities for project design.
65513, Exp. 09/30/21
Engineer of Work's Signature, PE Number & Expiration Date
Aaron Albertson
Print Name
Commercial Development Resources
Company
05/24/2021
Date
PDPSWQMP 2of27
PROJECT LOCATION
1050 AUTO CENTER DR
(.ADI D AD, CA
Priority Development Project (POP) SWQMP
BMW of Carlsbad PIResources
commerdw
PROJECT VICINITY MAP
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PDPSWQMP 3 of 27
Priority Development Project (POP) SWQMP
BMW of Carlsbad C tffimerda L' kpn
Routes
[Insert City's Storm Water Standard Questionnaire (Form E-34) here]
POP SWQMP 4of27
STORM WATER STANDARDS Dev&QPmflt Services
(J tv of Development Engineering QUESTIONNAIRE Land Engineering
Carlsbad 1635 Faraday Avenue E-34 (760) 602-2750
www,carlsbadca.gov
INSTRUCTIONS:
To address post-development pollutants that may be generated from development projects, the city requires that new
development and significant redevelopment priority projects incorporate Permanent Storm Water Best Management
Practices (BMPs) into the project design per Carlsbad BMP Design Manual (BMP Manual). To view the BMP Manual,
refer to the Engineering Standards (Volume 5).
This questionnaire must be completed by the applicant in advance of submitting for a development application
(subdivision, discretionary permits and/or construction permits). The results of the questionnaire determine the level of
storm water standards that must be applied to a proposed development or redevelopment project. Depending on the
outcome, your project will either be subject to STANDARD PROJECT' requirements or be subject to PRIORITY
DEVELOPMENT PROJECT' (PDP) requirements.
Your responses to the questionnaire represent an initial assessment of the proposed project conditions and impacts. City
staff has responsibility for making the final assessment after submission of the development application. If staff
determines that the questionnaire was incorrectly filled out and is subject to more stringent storm water standards than
initially assessed by you, this will result in the return of the development application as incomplete. In this case, please
make the changes to the questionnaire and resubmit to the city.
If you are unsure about the meaning of a question or need help in determining how to respond to one or more of the
questions, please seek assistance from Land Development Engineering staff.
A completed and sgned questionnaire must be submitted with each development project application. Only one
completed and signed questionnaire is required when multiple development applications for the same project are
submitted concurrently.
PROJECT INFORMATION
PROJECT NAME: BMW OF CARLSBAD PROJECT ID: MS2019.0003/ CDP2019-0013
ADDRESS: 1060 Auto Center Court, Carlsbad, CA 92008 APN: 211-080-11-00
The project is (check one): 0 New Development E1 Redevelopment
The total proposed disturbed area is: 161,503 ft2 (__1.71__j acres
The total proposed newly created and/or replaced impervious area is: 120,934 ft2 ( 2.78 ) acres
If your project is covered by an approved SWOMP as part of a larger development project, provide the project ID and the
SWQMP # of the larger development project:
Project ID: NIA SWQMP #: N/A
Then, go to Step 1 and follow the instructions. When completed, sign the form at the end and submit this with your
application to the city.
E-34 Page 1of 4 REV 02116
E-34 REV 04/17 1 Page 2 of 4
STEP I
TO BE COMPLETED FOR ALL PROJECTS
To determine if your project is a "development project", please answer the following question:
YES NO
Is your project LIMITED TO routine maintenance activity and/or repair/improvements to an existing building El or structure that do not alter the size (See Section 1.3 of the BMP Design Manual for guidance)?
If you answered "yes" to the above question, provide justification below then go to Step 5, mark the third box stating "my
project is not a 'development project' and not subject to the requirements of the BMP manual" and complete applicant
information.
Justification/discussion: (e.g. the project includes only interior remodels within an existing building):
If you answered "no" to the above question, the project is a 'development project', go to Step 2. -
STEP 2
TO BE COMPLETED FOR ALL DEVELOPMENT PROJECTS
To determine if your project is exempt from PDP requirements pursuant to MS4 Permit Provision E.3.b.(3), please answer
the following questions:
Is your project LIMITED to one or more of the following:
YES NO
1. Constructing new or retrofitting paved sidewalks, bicycle lanes or trails that meet the following criteria:
Designed and constructed to direct storm water runoff to adjacent vegetated areas, or other non
erodible permeable areas; El M Designed and constructed to be hydraulically disconnected from paved streets or roads;
C) Designed and constructed with permeable pavements or surfaces in accordance with USEPA
Green Streets guidance?
2. Retrofitting or redeveloping existing paved alleys, streets, or roads that are designed and constructed in o IN accordance with the USEPA Green Streets guidance?
3. Ground Mounted Solar Array that meets the criteria provided in section 1.4.2 of the BMP manual? 0 EJ
If you answered "yes" to one or more of the above questions, provide discussion/justification below, then go to Step 5, mark
the second box stating "my project is EXEMPT from PDP ..." and complete applicant information.
Discussion to justify exemption ( e.g. the project redeveloping existing road designed and constructed in accordance with
the USEPA Green Street guidance):
If you answered "no" to the above questions, your project is not exempt from PDP, go to Step 3.
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S'1EP3
TO BE COMPLETED FOR ALL NEW OR REDEV€tOPMENT PROJECTS
To determine if your project is a PDP, please answer the following questions (MS4 Permit Provision E.3.b.(1)):
YES NO
Is your project a new development that creates 10,000 square feet or more of impervious surfaces
collectively over the entire project site? This includes commercial, industrial, residential, mixed-use, 0 KI and public development projects on public or private land.
Is your project a redevelopment project creating and/or replacing 5,000 square feet or more of
impervious surface collectively over the entire project site on an existing site of 10,000 square feet or
more of impervious surface? This includes commercial, industrial, residential, mixed-use, and public
development projects on public or private land.
Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious surface collectively over the entire project site and supports a restaurant? A restaurant is
a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and 0 iXJ
refreshment stands selling prepared foods and drinks for immediate consumption (Standard Industrial
Classification (SIC) code 5812).
Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious
surface collectively over the entire project site and supports a hillside development project? A hillside 0 IXI
development project an_ any that is_ twenty-five or greater. _includes _development _natural _slope _percent
Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious surface collectively over the entire project site and supports a parking lot? A parking lot is El a land area or facility for the temporary parking or storage of motor vehicles used personally for
business or for commerce.
6, Is your project a new or redevelopment project that creates and/or replaces 5,000 square feet or more
of impervious street, road, highway, freeway or driveway surface collectively over the entire project
site? A street, road, highway, freeway or driveway is any paved impervious surface used for the
transportation of automobiles, trucks, motorcycles, and other vehicles.
Is your project a new or redevelopment project that creates and/or replaces 2,500 square feet or more
of impervious surface collectively over the entire site, and discharges directly to an Environmentally
Sensitive Area (ESA)? "Discharging Directly to" includes flow that is conveyed overland a distance of 0 IZJ 200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an
isolated flow from the project to The ESA (i.e. not commingled with flows from adjacent lands) *
Is your project a new development or redevelopment project that creates and/or replaces 5,000 square
feet or more of impervious surface that supports an automotive repair shop? An automotive repair > shop is a facility that is categorized in any one of the following Standard Industrial Classification (SIC)
codes: 5013, 5014, 5541, 7532-7534, or 7536-7539.
Is your project a new development or redevelopment project that creates and/or replaces 5,000 square
feet or more of impervious area that supports a retail gasoline outlet (RGO)? This category includes
RGO'S that meet the following criteria: (a) 5,000 square feet or more or (b) a project Average Daily
Traffic (AD T) of 100 or more vehicles per day.
Is your project a new or redevelopment project that results in the disturbance of one or more acres of land
and are expected to generate pollutants post construction?
Is your project located within 200 feet of the Pacific Ocean and (1) creates 2,500 square feet or more of
impervious surface or (2) increases impervious surface on the property by more than 10%? (CIVIC 0 EXJ 21.203.040)
If you answered "yes" to one or more of the above questions, your project is a PDP. If your project is a redevelopment
project, go to step 4. If your project is a new project, go to step 5, check the first box stating "My project is a POP . .
and complete applicant information.
If you answered "no" to all of the above questions, your project is a 'STANDARD PROJECT.' Go to step 5, check the
second box stating "My project is a 'STANDARD PROJECT'..." and complete applicant information.
E-34 Page 3of4 REV 04117
STEP 4
TO BE COMPLETED FOR REDEVELOPMENT PROJECTS THAT ARE PRIORITY DEVELOPMENT PROJECTS (POP)
ONLY
Complete the questions below regarding your redevelopment project (MS4 Permit Provision E.3.b.(2)):
YES NO
Does the redevelopment project result in the creation or replacement of impervious surface in an amount
of less than 50% of the surface area of the previously existing development? Complete the percent
impervious calculation below:
Existing impervious area (A) = 118,892 sq. ft. 0 FZI
Total proposed newly created or replaced impervious area (B) = 120,934 sq. ft.
Percent impervious area created or replaced (B/A)* 100 = 102 %
If you answered 'yes", the structural BMPs required for PDP apply only to the creation or replacement of impervious
surface and not the entire development. Go to step 5, check the first box stating "My project is a PDP ..," and complete
applicant information.
If you answered "no," the structural BMP's required for PDP apply to the entire development. Go to step 5, check the
check the first box stating "My project isaPDP ." and complete applicant information.
STEP 5
CHECK THE APPROPRIATE BOX AND COMPLETE APPLICANT INFORMATION
EI My project is a PDP and must comply with PDP stormwater requirements of the BMP Manual. I understand I must
prepare a Storm Water Quality Management Plan (SWQMP) for submittal at time of application.
0 My project is a 'STANDARD PROJECT' OR EXEMPT from POP and must only comply with 'STANDARD PROJECT'
stormwater requirements of the BMP Manual. As part of these requirements, I will submit a "Standard Project
Requirement Checklist Form E-36' and incorporate low impact development strategies throughout my project.
Note: For projects that are close to meeting the PDP threshold, staff may require detailed impervious area calculations
and exhibits to verify if 'STANDARD PROJECT' stormwater requirements apply.
My Project is NOT a 'development project' and is not subject to the requirements of the BMP Manual.
Applicant Information and Signature Box
Applicant Name: Applicant Title:
Applicant Signature: Date:
nvrunmeniaiiy oensiive ireas inciuoe OUT are not iimrtea to an r.tean vvater Act ectron U3(0) impairea water mates; areas designated as Areas of Special
Biological Significance by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); water bodies
designated with the RARE beneficial use by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and
amendments); areas designated as preserves or their equivalent under the Multi Species Conservation Program within the Cities and County of San Diego; Habitat
Management Plan; and any other equivalent environmentally sensitive areas which have been identified by the City.
This Box for City Use Only EMMEAM
YES NO
City Concurrence: o
By: I Date;
Project ID:
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E-34 Page 4 of 4 REV 04117 1
Priority Development Project (POP) SWQMP commmu
BMW of Carlsbad b - -
SITE INFORMATION CHECKLIST
Project Summary Information
Project Name BMW of Carlsbad
Project ID MS2019-0003, CDP20I9-0013
Project Address 1060 Auto Center Court
Carlsbad, CA 92008
Assessor's Parcel Number (APN) 211-080-11-00
Project Watershed (Hydrologic Unit) Carlsbad 904, Agua Hedionda (904.3)
Parcel Area 3.708 Acres (161,503 Square Feet)
Existing Impervious Area
(subset of Parcel Area)
Area
2.729 Acres ( 118 892 Square Feet)
to be disturbed by the project
(Project Area) 3.708 Acres (161,503 Square Feet)
Project Proposed Impervious Area
(subset of Project Area) 2.776 Acres (120,934 Square Feet)
Project Proposed Pervious Area
(subset of Project Area) 0.931 Acres (40,568 Square Feet)
Note: Proposed Impervious Area + Proposed Pervious Area = Area to be Disturbed by the
Project. This may be less than the Parcel Area.
POP SWQMP 5 of 27
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Priority Development Project (PDP) SWQMP
BMW of Carlsbad C I >1 I
Description of Existing Site Condition and Drainaqe Patterns
Current Status of the Site (select all that apply):
Existing development
El Previously graded but not built out
El Agricultural or other non-impervious use
El Vacant, undeveloped/natural
Description /Additional Information:
Existing project site is an automotive dealer and repair complex with onsite AC pavement
parking lot, drive aisles and landscape areas.
Existing Land Cover Includes (select all that apply):
Vegetative Cover
El Non-Vegetated Pervious Areas
Impervious Areas
Description / Additional Information:
Existing project site is 26% pervious landscape and 74% impervious area (roof, parking lot,
sidewalks, etc.)
Underlying Soil belongs to Hydrologic Soil Group (select all that apply):
El NRCS Type A
NRCS Type B
O NRCS Type C
El NRCS Type D
Approximate Depth to Groundwater (OW):
El GW Depth <5 feet
El 5 feet < GW Depth < 10 feet
El 10 feet < GW Depth <20 feet
GW Depth >20 feet
Existing Natural Hydrologic Features (select all that apply):
El Watercourses
El Seeps
C1 Springs
El Wetlands
None
Description /Additional Information:
N/A
POP SWQMP 6of27
Priority Development Project (PDP) SWQMP
BMW of Car[sbad CIAResaw4s
C m2cl
on of Existing Site Topography and Drainage:
[How is storm wafer runoff conveyed from the site? At a minimum, this description should answer
(1) whether existing drainage conveyance is natural or urban; (2) describe existing constructed
storm water conveyance systems, if applicable; and (3) is runoff from offsite conveyed through
the site? if so, describe]
The existing site is an automotive detail and repair complex. Onsite stormwater flows away from
the existing building, across the AC pavement parking lot, to curb and gutter around perimeter of
site, then flows into onsite catch basin. The onsite catch basins discharge directly to the City's
storm drain system. Runoff in the perimeter landscaping flows offsite and into existing catch
basins in the public-right-of way before joining the City's storm drain system. The City's storm
drain system discharges to Agua Hedionda Lagoon, then to the Pacific Ocean.
PDPSWQMP 70f27
Priority Development Project (PDP) SWQMP
BMW of Carlsbad C Resawms
Description of Proposed Site Development and Drainage Patterns
Project Description I Proposed Land Use and/or Activities:
The proposed project is the construction of a new BMW dealership with a 2-story building with
1.4 acres of rooftop parking. This will include new onsite AC pavement parking areas, drive aisles,
landscape setbacks, landscape islands, and trash enclosure.
List/describe proposed impervious features of the project (e.g., buildings, roadways,
parking lots, courtyards, athletic courts, other impervious features):
Proposed impervious features include a new 2-story building with rooftop parking, AC pavement
parking lot with drive aisles, and concrete walkways. The proposed condition will be 75%
impervious areas.
List/describe proposed pervious features of the project (e.g. landscape areas):
Proposed pervious features include landscaped areas along property lines and throughout the
project site. In addition, permeable payers are provided in parking areas to reduce the total
impervious area for the project site. Permeable payers are not considered treatment control
BMPs. The proposed condition will be 25% impervious areas.
Does the project include grading and changes to site topography?
Yes
0 N
Description I Additional Information:
The project site will be regraded to construct a 2-story, at-grade building in the center of the site.
The surrounding area in the project site will be regraded to capture all rooftop and parking lot
flows onsite. The landscape area along Cannon Road will remain as steep slopes from the
property line down to the public right-of-way. Landscape areas along the property line on Car
County Drive and Auto Center Court will continue to slope as it does in existing condition - part
of the area will slope towards the road, and part will slope onto the project site. Project site flows
will be directed to biofiltration basins (two with partial retention) for treatment and discharge to the
underground detention system. The retaining walls along the western property line will remain in
place. The project site does not receive run-on from outside property limits.
Does the project include changes to site drainage (e.g., installation of new storm water
conveyance systems)?
Yes
0 N
Description I Additional Information:
New storm drain system, biofiltration basins, biofiltration basins with partial retention and
underground detention system to capture, treat, and detain stormwater runoff onsite prior to
draining offsite to meet LID and hydromodification requirements. Onsite runoff sheetfiows to
proposed biofiltration areas (some with partial retention) for treatment prior to discharging to
underground detention. Rooftop runoff will be captured and treated via BioClean's Modular
Wetland System (MWS) prior to discharging to the underground detention system. Detention vault
outlet structure will drain to the existing private storm drain lateral on Cannon Road.
PDP SWQMP 8o127 I
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Priority Development Project (PDP) SWQMP
BMW of Carlsbad C cwmwdw
alRommes
Identify whether any of the following features, activities, and/or pollutant source areas
will be present (select all that apply):
On-site storm drain inlets
o Interior floor drains and elevator shaft sump pumps
O Interior parking garages
O Need for future indoor & structural pest control
Landscape/Outdoor Pesticide Use
0 Pools, spas, ponds, decorative fountains, and other water features
0 Food service
Refuse areas
0 Industrial processes
0 Outdoor storage of equipment or materials
Vehicle and Equipment Cleaning
Vehicle/Equipment Repair and Maintenance
O Fuel Dispensing Areas
O Loading Docks
Fire Sprinkler Test Water
Miscellaneous Drain or Wash Water
Plazas, sidewalks, and parking lots
PDP SWQMP 9 of 27
Priority Development Project (PDP) SWQMP COMINIEL
c ommrdw
BMW of Carlsbad
Identification of Receiving Water Pollutants of Concern
Describe path of storm water from the project site to the Pacific Ocean (or bay, lagoon,
lake or reservoir, as applicable):
The onsite detention system will discharge to the existing private storm drain lateral at the
northwest property corner. Runoff from the perimeter landscaping along Cannon Road flows north
to the gutter in the public right-of-way, then to an existing public storm drain inlet approximately
600-ft west of the project site. Runoff from the perimeter landscaping along Car County Drive
flows east to the gutter in the public right-of-way, then north to an existing public storm drain inlet
on Car Country Drive near the northeast property corner. Runoff from the perimeter landscaping
along Auto Center Court flows south to the gutter in the public right-of-way, then to an existing
public storm drain inlet located west of the project site at the end of the cul-de-sac.
The existing private storm drain lateral and public storm drain inlets convey flows to the existing
City storm drain line flowing west along Cannon Road. This conveys runoff to the Agua Hedionda
Lagoon and ultimately drains to the Pacific Ocean.
List any 303(d) impaired water bodies within the path of storm water from the project site to the
Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable), identify the pollutant(s)/
stressor(s) causing impairment, and identify any TMDLs for the impaired water bodies:
303(d) Impaired Water Body Pollutant(s)/Stressor(s) TMDLs
Agua Hedionda Lagoon Indicator Bacteria Indicator Bacteria Invasive
Species, Sedimentation/Siltation
Identification of Project Site Pollutants
Identify pollutants anticipated from the project site based on all proposed use(s) of the site (see
BMP Design Manual Appendix B.6): Commercial Development (>I ac), Parking Lot
Pollutant Not Applicable to Anticipated from the Also a Receiving
Water Pollutant of the Project Site Project Site Concern
Sediment X
Nutrients X
Heavy Metals X
Organic Compounds X
Trash & Debris X
Oxygen Demanding x Substances
Oil& Grease X
Bacteria & Viruses X X
Pesticides X
PDP SWQMP 10 of 27
Priority Development Project (PDP) SWQMP
BMW of Carlsbad CW4ECR0Z9=CeS
Hydromodification Management Requirements
Do hydromodification management requirements apply (see Section 1.6 of the BMP
Design Manual)?
Yes, hydromodification management flow control structural BMPs required.
III No, the project will discharge runoff directly to existing underground storm drains
discharging directly to water storage reservoirs, lakes, enclosed embayments, or the Pacific
Ocean.
LJ No, the project will discharge runoff directly to conveyance channels whose bed and bank
are concrete-lined all the way from the point of discharge to water storage reservoirs, lakes,
enclosed embayments, or the Pacific Ocean.
0 No, the project will discharge runoff directly to an area identified as appropriate for an
exemption by the WMAA for the watershed in which the project resides.
Description /Additional Information (to be provided if a 'No' answer has been selected above):
N/A
Critical Coarse Sediment Yield Areas*
*This Section only required if hydromodification management requirements apply
Based on the maps provided within the WMAA, do potential critical coarse sediment
yield areas exist within the project drainage boundaries?
DYes
0 No, No critical coarse sediment yield areas to be protected based on WMAA maps
If yes, have any of the optional analyses presented in Section 6.2 of the BMP Design
Manual been performed?
0 6.2.1 Verification of Geomorphic Landscape Units (GLUs) Onsite
0 6.2.2 Downstream Systems Sensitivity to Coarse Sediment
0 6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite
0 No optional analyses performed, the project will avoid critical coarse sediment yield areas
identified based on WMAA maps
If optional analyses were performed, what is the final result?
0 No critical coarse sediment yield areas to be protected based on verification of GLUs onsite
0 Critical coarse sediment yield areas exist but additional analysis has determined that
protection is not required. Documentation attached in Attachment 8 of the SWQMP.
O Critical coarse sediment yield areas exist and require protection. The project will implement
management measures described in Sections 6.2.4 and 6.2.5 as applicable, and the areas
are identified on the SWQMP Exhibit.
Discussion /Additional Information:
N/A
PDP SWQMP 11 of 27
Priority Development Project (POP) SWQMP
BMW of Carlsbad
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Flow Control for Post-Project Runoff*
*This Section only required if hydromodification management requirements apply
List and describe point(s) of compliance (POCs) for flow control for hydromodification
management (see Section 6.3.1). For each POC, provide a POC identification name or number
correlating to the project's HMP Exhibit and a receiving channel identification name or number
correlating to the project's HMP Exhibit.
There is I point of compliance (POC) for flow control for hydromodification management for the
proposed project:
DMA-1 & DMA-2 - City SD System - POC #1 -* Aqua Hedionda Lagoon
DMA-i flows to City SD system via existing private lateral on Cannon Road. DMA-2 flows to City
SD system via existing inlets in the public ROW on Auto Center Court, Car Country Drive, and
Cannon Road.
POC #1 is located at STA 31+80.00 of existing City storm drain line on Cannon Road, east of
Paseo Del Norte, per City Drawing No. 285-2 (sheets 6 and 10). The storm drain system conveys
flows west along Cannon Road, then discharges north to Agua Hedionda Lagoon.
Has a geomorphic assessment been performed for the receiving channel(s)?
No, the low flow threshold is 0.1Q2 (default low flow threshold)
E Yes, the result is the low flow threshold is 0.1Q2
LJ Yes, the result is the low flow threshold is 0.3Q2
LI Yes, the result is the low flow threshold is 0.5Q2
If a geomorphic assessment has been performed, provide title, date, and preparer:
N/A
Discussion / Additional Information: (optional)
N/A
Other Site Requirements and Constraints
When applicable, list other site requirements or constraints that will influence storm water
management design, such as zoning requirements including setbacks and open space, or City
codes governing minimum street width, sidewalk construction, allowable pavement types, and
drainage requirements.
25'-wide landscape setback along Cannon Road
10'-wide landscape setback along Car Country Drive
10'-wide landscape setback along Auto Center Court
Optional Additional Information or Continuation of Previous Sections As Needed
This space provided for additional information or continuation of information from previous
sections as needed.
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POP SWQMP I2of27 I
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Priority Development Project (PDP) SWQMP
BMW of Carlsbad ClAwsmMs ~
cwmtdw
[Insert City's Standard Project Requirement Checklist Form E-36 (here)]
PDP SWQMP 13 of 27
!~Clty of
C Isbad
STANDARD PROJECT
REQUIREMENT
CHECKLIST
E36
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
Project Information
Project Name: BMW of Carlsbad
Project ID: MS2019-0003
DWG No. or Building Permit No.: CDP2019-0013/SDP20I9-0005, DWG NO. 529-6A
Source Control BMPs
All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible. See
Chapter 4 and Appendix El of the BMP Design Manual (Volume 5 of City Engineering Standards) for information to
implement source control BMPs shown in this checklist.
Answer each category below pursuant to the following.
"Yes" means the project will implement the source control BMP as described in Chapter 4 and/or Appendix El of the
Model BMP Design Manual. Discussion/justification is not required.
"No" means the BMP is applicable to the project but it is not feasible to implement. Discussion/justification must be
provided. Please add attachments if more space is needed.
"N/A" means the BMP is not applicable at the project site because the project does not include the feature that is
addressed by the BMP (e.g., the project has no outdoor materials storage areas). Discussion/justification may be
provided.
Source Control Requirement Applied?
-
SC-1 Prevention of Illicit Discharges into the M54 IZI Yes 0 No 0 N/A
Discussion/justification if SC-1 not implemented: -,
SC-2 Storm Drain Stenciling or Signage IXl Yes 0 No 0 N/A
Discussion/justification if SC-2 not implemented:
SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind o Yes 0 No N/A Dispersal
Discussion/justification if SC-3 not implemented:
Outdoor material storage areas are not proposed for this project.
E-36 Page 1 of 4 Revised 09116
Source Control Requirement (continued)
SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and
Wind Dispersal ri Yes .. e
Applied?
No N/A
Discussion/justificaton if SC4 not implemented:
Outdoor work areas not proposed for this project. All work areas will be indoor.
SC-6 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal j IX Yes 0 No 0 N/A
Discussion/justificalion if SC-5 not implemented:
SC-6 Additional BMPs based on Potential Sources of Runoff Pollutants must answer for each source listed below and
identify additional BMPs. (See Table in Appendix E. 1 of BMP Manual for guidance).
IX On-site storm drain inlets IX Yes 0 No 0 N/A
IJ Interior floor drains and elevator shaft sump pumps IX Yes 0 No 0 N/A
Interior parking garages 0 Yes 0 No IX N/A
Need for future indoor & structural pest control IX Yes 0 No 0 N/A
IX Landscate/Outdoor Pesticide Use IX Yes 0 No 0 N/A
Pools, spas, ponds, decorative fountains, and other water features 0 Yes 0 No IX N/A
Food service 0 Yes 0 No IN N/A
r.J Refuse areas IX Yes 0 No 0 N/A
Industrial processes 0 Yes 0 No IX N/A
Outdoor storage of equipment or materials 0 Yes 0 No IX N/A
IX Vehicle and Equipment Cleaning J Yes 0 No 0 N/A
LX Vehicle/Equipment Repair and Maintenance IX Yes 0 No 0 N/A
Fuel Dispensing Areas 0 Yes 0 No IX N/A
Loading Docks 0 Yes 0 No IX N/A
IX Fire Sprinkler Test Water 0 Yes 0 No 0 N/A
IKI Miscellaneous Drain or Wash Water
- IX Yes 0 No 0 N/A
IX Plazas, -sidewalks, and parking lots M Yes 0 No 0 N/A
For "Yes" answers, identify the additional BMP per Appendix El. Provide iustiflcation for "Non answers.
- Onsite storm drain inlets will be marked with "NO DUMPING" signs.
- Interior floor drains and sum pumps will be plumbed to sanitary sewer.
- Landscape areas will be designed to minimize use of fertilizers and pesticides.
- Trash enclosure area will be covered and protected form run-on
- Vehicle and equipment cleaning is limited to rinsing-cars with only water
- Parking lots and sidewalks will be swept regularly and debris will be collected prior to entering the storm drain.
E-36 Page 2of4 Revised 09/16
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Site Design BMPs
All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible. See
Chapter 4 and Appendix E.2 thru E.6 of the BMP Design Manual (Volume 5 of City Engineering Standards) for information
to implement site design BMPs shown in this checklist.
Answer each category below pursuant to the following.
"Yes" means the project will implement the site design BMPs as described in Chapter 4 and/or Appendix E.2 thru E.6 of
the Model BMP Design Manual. Discussion/justification is not required.
"No" means the BMPs is applicable to the project but it is not feasible to implement. Discussionustification must be
provided. Please add attachments if more space is needed.
'NIA" means the BMPs is not applicable at the project site because the project does not include the feature that is
addressed by the BMPs (e.g., the project site has no existing natural areas to conserve). Discussion/justification may be
provided.
Site Design Applied? _Requirement
SD-1 Maintain -N—a-tural —Drnage Pathways and Hydrologic Features - - 0 Yes I 0 No fN/A
Discussion/justification if SD-1 not implemented:
Existing project site has been developed as a commercial center with minimal interior landscaping and no natural
drainage pathways or hydrologic features to protect.
SD-2 Conserve Natural Areas, Soils, and Vegetation I tl Yes I 0 No I 0 N/A
SD-3 Minimize Impervious Area M Yes 0 No I 0 N/A
Discussion/justification if SD-3 not implemented:
SD-4 Minimize Soil Compaction 191 Yes I 0 No I 0 N/A
Discussion/justification if SD-4 not implemented:
SD-5 Impervious Area Dispersion 0 Yes I 0 No I 0 N/A
Discussion/justification if SD-5 not implemented:
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E-36 Page 3 of 4 Revised 09116
Site Design Rquiremenjçmtinued)
SD-6 Runoff Collection
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IN Yes 0 NoJD N/A
Discussion/justification if SD-6 not implemented:
SD-7 Landscaping with Native or Drought Tolerant Species I Yes I 0 No I 0 N/A
Discussion/justification if SD-7 not implemented:
SD-8 Harvesting and Using Precipitation I 0 Yes I IZI No I 0 N/A
Discussion/justification if SD-8 not implemented:
Harvest and Use determined infeasible due to low water usage for commercial site.
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E-36 Page 4of4 Revised 09116
.
Priority Development Project (PDP) SWQMP I
BMW of Carlsbad cl*=-
SUMMARY OF PDP STRUCTURAL BMPS
PDP Structural BMPs I
All POPs must implement structural BMPs for storm water pollutant control (see Chapter 5 of the BMP Design Manual)
Selection of POP structural BMPs for storm water pollutant control must be based on the selection process described
in Chapter 5 PDPs subject to hydromodification management requirements must also implement structural BMPs for
flow control for hydromodification management (see Chapters of the BMP Design Manual). Both storm water pollutant
control and flow control for hydromodification management can be achieved within the same structural BMP(s)
POP structural BMPs must be verified by the City at the completion of construction. This may include requiring the
project owner or project owners representative to certify construction of the structural BMPs (see Section 112 of the
BMP Design Manual) PDP structural BMPs must be maintained into perpetuity, and the City must confirm the
maintenance (see Section 7 of the BMP Design Manual).
Use this form to provide narrative description of the general strategy for structural BMP implementation at the project
site in the box below, Then complete the POP structural BMP summary information sheet for each structural BMP within
the project (copy the BMP summary information page as many times as needed to provide summary information for
each individual structural BMP).
Describe the general strategy for structural BMP implementation at the site. This information must describe how the
steps for selecting and designing storm water pollutant control BMPs presented in Section 5.1 of the BMP Design
Manual were followed, and the results (type of BMPs selected). For projects requiring hydromodification flow control
BMPs, indicate whether pollutant control and flow control BMPs are integrated together or separate.
The BMP selection process has been developed in accordance with the new MS4 Permit (R9-2013-0001
as amended by R9-2015-0001 and R9-2015-0100). Harvest and re-use is considered impractical for use
on the project site due to it being a proposed commercial area with low water usage. Due to inadequate
infiltration rates within the upper 5 feet of site soils and the presence of engineered fill and dense to very
dense formation, the project geotechnical engineer concluded that full infiltration is infeasible for the entire
project site. Infiltration in any capacity is prohibited adjacent to the western property line or in the northwest
property corner due to nearby structures and hillside landscaping. However, partial infiltration is feasible at
the northeast and southeast property corners. Therefore, biofiltration areas with partial retention (PR-1) are
proposed to treat project flows for pollutant control on the eastern half of the site and lined biofiltration areas
(BF-1) are proposed to treat runoff from the western half of the site. Proprietary Biofiltration BMP (BF-3) is
proposed for runoff from building roof area due to site layout restrictions due to the nature of a car
dealership. Permeable payers are provided in parking areas east and south of the proposed building to
reduce the project site's total impervious area. The permeable payers are not considered treatment control
BMPs.
For DMA-IA and DMA-1 B, onsite stormwater will sheetfiow to local biofiltration areas with partial retention
for treatment and flow control, then routed to the underground detention vault for hydromodification
management flow control prior to discharging from the project site.
For DMA-IC and DMA-ID, onsite stormwater will sheetfiow to local biofiltration areas with impermeable
liners for treatment and flow control, then routed to the underground detention vault for hydromodification
management flow control prior to discharging from the project site.
For DMA-I E, stormwater runoff from rooftop area will be collected at a localized inlet and routed thru I BioClean's Modular Wetland System (MWS) for treatment prior to discharging to the underground detention
vaults for hydromodification management flow control.
DMA-2A is comprised of self-mitigating landscape area and does not require pollutant control. The
hydromodification management for this area is accounted for by the underground detention system (flow
control BMP).
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PDP SWQMP 14 of 27 I
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Priority Development Project (POP) SWQMP
BMW of Carlsbad
cwftllwk~01ROSOWAS
Structural BMP Summary Information
Structural BMP ID No. I (DMA-IA)
DWG: No. 529-6A, Sheets 08 & 11
Type of structural BMP:
O Retention by harvest and use (HU-1)
O Retention by infiltration basin (IN F-1)
U Retention by bioretention (INF-2)
O Retention by permeable pavement (INF-3)
Partial retention by biofiltration with partial retention (PR-1)
U Biofiltration (BF-1)
U Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or
biofiltration BMP (provide BMP type/description and indicate which onsite retention or
biofiltration BMP it serves in discussion section below)
U Detention pond or vault for hydromodification management
U Other (describe in discussion section below)
Purpose:
U Pollutant control only
U Hydromodification control only
Combined pollutant control and hydromodification control
U Pre-treatment/forebay for another structural BMP
U Other (describe in discussion section below)
Discussion (as needed):
Bioflltration area with partial retention is proposed to treat runoff from DMA-1A and provide flow
control for the project site's hydromodification requirement. Geotechnical engineer determined
that full infiltration is infeasible for the project site.
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BMW of Carlsbad
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Structural BMP Summary Information
-:
Structural BMP ID No.2 (DMA-113)
DWG: No. 529-6A, Sheets 08 & ii
Type of structural BMP:
El Retention by harvest and use (HIJ-1)
El Retention by infiltration basin (IN F-1)
El Retention by bioretention (INF-2)
LI Retention by permeable pavement (lNF-3)
Z Partial retention by biofiltration with partial retention (PR-1)
O Biofiltration (BF-1)
O Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or
biofiltration BMP (provide BMP type/description and indicate which Onsite retention or
biofiltration BMP it serves in discussion section below)
O Detention pond or vault for hydromodification management
0 Other (describe in discussion section below)
Purpose:
O Pollutant control only
O Hydromodification control only
El Combined pollutant control and hydromodification control
O Pre-treatment/forebay for another structural BMP
O Other (describe in discussion section below)
Discussion (as needed):
Biofiltration basin with partial retention is proposed to treat runoff from DMA-1 B and provide flow
control for the project site's hydromodification requirement. Geotechnical engineer determined
that full infiltration is infeasible for the project site.
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Priority Development Project (PDP) SWQMP
BMW of Carlsbad
caftlZah,
pn Coerd
P1L' Reoutc.es
- Structural BMP Summary Information
Structural BMP ID No. 3 (DMA-IC)
DWG: No. 529-6A, Sheets 08 & ii
Type of structural BMP:
El Retention by harvest and use (H U-1)
El Retention by infiltration basin (lNF-I)
El Retention by bioretention (INF-2)
El Retention by permeable pavement (INF-3)
El Partial retention by biofiltration with partial retention (PR-1)
Biofiltration (BF-1)
El Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or
biofiltration BMP (provide BMP type/description and indicate which onsite retention or
biofiltration BMP it serves in discussion section below)
El Detention pond or vault for hydromodification management
El Other (describe in discussion section below)
Purpose:
El Pollutant control only
El Hydromodification control only
Combined pollutant control and hydromodification control
El Pre-treatmentlforebay for another structural BMP
El Other (describe in discussion section below)
Discussion (as needed):
Biofiltration basin with an impermeable liner is proposed to treat runoff from DMA-i C and provide
flow control for the project site's hydromodification requirement. Geotechnical engineer
determined that infiltration is infeasible in the project site's northwest corner.
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BMW of Carlsbad
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Structural BMP Summary Information
Structural BMP ID No.4 (DMA-ID)
DWG: No. 529-6A, Sheets 08 & 11
Type of structural BMP:
O Retention by harvest and use (HLJ-1)
LI Retention by infiltration basin (INF-1)
LI Retention by bioretention (INF-2)
O Retention by permeable pavement (INF-3)
LI Partial retention by biofiltration with partial retention (PR-1)
ER Biofiltration (BF-1)
LI Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or
biofiltration BMP (provide BMP type/description and indicate which onsite retention or
biofiltration BMP it serves in discussion section below)
LI Detention pond or vault for hydromodification management
LI Other (describe in discussion section below)
Purpose:
LI Pollutant control only
LI Hydromodification control only
Combined pollutant control and hydromodification control
LI Pre-treatment/forebay for another structural BMP
LI Other (describe in discussion section below)
Discussion (as needed):
Biofiltration basin with an impermeable is proposed to treat runoff from DMA-1 D and provide flow
control for the project site's hydromodification requirement. Geotechnical engineer determined
that infiltration is infeasible along the project site's western property line.
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Priority Development Project (PDP) SWQMP
BMW of Carlsbad C Coffimerdal VIResources
Structural BMP Summary Information
Structural BMP ID No. 5 (DMA-11E)
DWG: No. 529-6A, Sheets 08 & 11
Type of structural BMP:
U Retention by harvest and use (HU-1)
U Retention by infiltration basin (lNF-1)
O Retention by bioretention (INF-2)
0 Retention by permeable pavement (INF-3)
O Partial retention by biofiltration with partial retention (PR-1)
0 Biofiltration (BF-1)
0 Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or
biofiltration BMP (provide BMP type/description and indicate which onsite retention or
biofiltration BMP it serves in discussion section below)
0 Detention pond or vault for hydromodification management
Other (describe in discussion section below)
Purpose:
Z Pollutant control only
C Hydromodification control only
O Combined pollutant control and hydromodification control
O Pre-treatment/forebay for another structural BMP
O Other (describe in discussion section below)
Discussion (as needed):
Other = Proprietary Biofiltration BMP (BF-3)
BioClean Modular Wetland System (MWS) flow-thru device proposed to treat rooftop runoff from
DMA-1E.
Geotechnical engineer determined that full infiltration is infeasible for the project site. Providing
an onsite biofiltration basin for this area would require approximately 1,550 sq-ft, which would
reduce the parking count by a total of 10 stalls. Due to the nature of the project site as a car
dealership and limited non-hillside landscaping, the use of biofiltration basin for treatment of
rooftop runoff is infeasible.
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PDP SWQMP 19 of 27
Priority Development Project (POP) SWQMP
BMW of Carlsbad C Commeda
YW Resources
Structural BMP Summary Information
Structural BMP ID No. 6 (all of DMA-I)
DWG: No. 529-6A, Sheets 08 & 12
Type of structural BMP:
El Retention by harvest and use (HU-1)
El Retention by infiltration basin (INF-1)
El Retention by bioretention (lNF-2)
El Retention by permeable pavement (INF-3)
o Partial retention by biofittration with partial retention (PR-1)
El Biofiltration (BF-1)
El Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or
biofiltration BMP (provide BMP type/description and indicate which onsite retention or
biofiltration BMP it serves in discussion section below)
Detention pond or vault for hydromodification management
El Other (describe in discussion section below)
Purpose:
El Pollutant control only
Hydromodification control only
El Combined pollutant control and hydromodification control
El Pre-treatment/forebay for another structural BMP
El Other (describe in discussion section below)
Discussion (as needed):
Proposed underground detention system (solid 8' dia. CMP by Contech) is proposed for
hydromodification management for runoff from entire site. Project site plan shows two vaults
(BMP-6A and 613) that are set at the same invert elevation and hydraulically connected to act as
one system.
Geotechnical engineer determined that full infiltration is infeasible for the project site.
PDP SWQMP 20 of 27
Priority Development Project (POP) SWQMP
BMW of Carlsbad
ATTACHMENT I
BACKUP FOR POP POLLUTANT CONTROL BMPS
This is the cover sheet for Attachment 1.
Check which Items are Included behind this cover sheet:
Attachment
Sequence Contents Checklist
DMA Exhibit (Required)
Attachment
la See DMA Exhibit Checklist on the 0 Included
back of this Attachment cover sheet.
(24"x36" Exhibit typically required)
Tabular Summary of DMAs Showing El Included on DMA Exhibit in DMA ID matching DMA Exhibit, DMA Attachment la Attachment Area, and DMA Type (Required)*
lb
*Provide table in this Attachment OR Included as Attachment I b,
on DMA Exhibit in Attachment 1 separate from DMA Exhibit
Form 1-7, Harvest and Use Feasibility
Screening Checklist (Required
Attachment unless the entire project will use 0 Included
Ic infiltration BMPs) El Not included because the entire
project will use infiltration BMPs
Refer to Appendix 13.3-1 of the BMP
Design Manual to complete Form 1-7.
Form 1-8, Categorization of Infiltration
Feasibility Condition (Required
unless the project will use harvest 0 Included
Attachment and use BMPs) El Not included because the entire
Id project will use harvest and use
Refer to Appendices C and D of the BMPs
BMP Design Manual to complete
Form 1-8.
Pollutant Control BMP Design
Worksheets / Calculations
(Required)
Attachment Included le Refer to Appendices B and E of the
BMP Design Manual for structural
pollutant control BMP design
guidelines
U PDPSWQMP 21 of 27
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Priority Development Project (PDP) SWQMP Conmdal
BMW of Carlsbad Cl AlRer4trCes
Use this checklist to ensure the required
information has been included on the DMA Exhibit:
The DMA Exhibit must identify:
Underlying hydrologic soil group
Approximate depth to groundwater
Existing natural hydrologic features (watercourses, seeps, springs, wetlands)
Critical coarse sediment yield areas to be protected (if present)
Existing topography and impervious areas
Existing and proposed site drainage network and connections to drainage offsite
Proposed grading
Proposed impervious features
Proposed design features and surface treatments used to minimize imperviousness
Drainage management area (DMA) boundaries, DMA ID numbers, and DMA areas (square
footage or acreage), and DMA type (i.e, drains to BMP, self-retaining, or self-mitigating)
Structural BMPs (identify location and type of BMP)
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PDP SWQMP 22o127 I
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ATTACHMENT 1A:
[I1kATA1
I
-- - - CANNON ROAD LEGEND
4022,492 - - lls$' 22 32032
WNCMTE - M4—U— - or 027, 4-0.04- NISCHARGC~;, To 034
7,)', 'o21-M - - ,[A sT / P 4- 2 tO 34-4-040.00 - '.1— 13 -.0"") 5Ffl ',TI V "4-All tvi
I PO L
OCIP 4-4-4-A OVA 8,3044-4-AlP N. L,.'J_s l . - 2,,jA2,4204,3..,82Y QUR
P14-4-To 00034-1314-
-
8-
n------o -7— Me R J
DMA-11C. .1 DM \ .
I
P4-4-8210024--A D. ..'. -_-._---. 4- So. ''-r r8,A'o3-r-'w
I L 1 I CCSYA ANALYSIS
r r°"- O- p Li . 2240022. 4-4- "3 12244-A4-4-4-IM3NILOAA.A81313424'S100010103,IMM4-141
4- I...............................:.............................
..
4- DMA 2A . . BMP DETAILS:
3
DMA SUMMARY:
I 11 1 I I
- L . . .. . MA4A'+81OF19AflNW/9ET1210909 9130001
's . 4- __._ __ S 4- if ({1 4- 2.1 MW 0401 .2.2 3fl.0-5%) 8.324 0.05%
LI] V 'Ed I I
z
'S,_ ...- , I . $ OMA.l,9,Iwu,nhlouw/onlura 412(10122
I 4- ii ' I 1.2 (86f4-03v9,,S('t 2.406 0.125 tj
, .L_-I]I] ., 1 ,1 - . 2.2 S40$S40,14042l 2.202 12029 F .s / .23 .951199828,5.254-3 14-34 0.1124
4-9, '. ..fl •I5I ,1 ' II 4- .
,,. - " IS
. / - /' , 4, / 0A.lC4Bl1106TM120t98693129102
0221
/ 2.2 02709599$ 21.611 8,101
- IS "' F / , I / 1.2 695100486(8,04-2,1 1,964 22.036
-. 4- 4- 4' 4'- "' I I 3904841302232(0130390092034130001 531 4- DMA 0340
- l
, - OS 06.13,3230.9,9555 2,13 00,3 <)-
/lu it
.1000,269 3212M02210421936 961399120091
2*1 :;:;II : : 0282
S.31$
8201311358, 8,3 1104
V$l')i4-AL4-MP.4. S IDMA-18i,4- 911_s'4-F.13F0i(P4-i.4-i4-44011 4-
Al I4Y4-1140M04-II22$OAISO.'.I 1 1 'S i . 4- 4 / 0 ,1E03i' •S,..,.__i I--- * ................. --------.--4-'--------------------.----------r.. .
27 JC1u824-LAM4--2- /1 7 / 20 0 20 40
I H /A/
/
lcLcA
- . Sit
1A-2Al4- -14 , / PREPARED -OR: PREPARED BY: SWQMPAITACHMENT IA: - 86'44-'QD2, 19232,73- 4 L 'T ' - - iT - ------ -- - . / =22tHFL '
DMA EXHIBIT - - FORT LALJOEROALE. FL34-30 Commercial 4-
/ CONTA,1Cj"-P0V,-LL Development
I>lResources BMW OF CARLSBAD
AUTO CENTER CT .-
/
4-263? 3o3 T14(R01. 5060 AUTO CENTER COURT - -- ---' — ------ - - C/RLSAD, CA 92W8
ATTACHMENT 1B:
TTACHMENT ib: DMA SUMMARY
Pre-Developed Condition
DMA Type ID
Area
(SF)
Area
(AC)
DMA-1 -* POC #1
1.1 Natural (B, 0-5%) 161,503 3.708
161,503 3.708
POC 41 TOTAL 161,503 3.708
PROJECT: BMW of Carlsbad
LOCATION: Carlsbad, CA
DATE: 05/21/021
Post-Developed Condition
DMA Area Area
ID Type (SF) (Ac)
DMA-1A 4 BIOFILTRATION W/ RETENTION 9 POC Ui
1.1 Roof/Pavement 19,664 0.451
1.2 Landscape (B, 0-5%) 2,314 0.053
1.3 Landscape (B, 5-15%) 520 0,012
1.4 Landscape (B, >15%) 387 0.009
1.5 Permeable Payers 9,589 0.220
32,474 0.746
DMA-113 4 BIOFILTRATION W/ RETENTION 4 POC #1
1.1 Roof/Pavement 8,486 0.195
1.2 Landscape (B, 0-5%) 1,281 0.029
1.3 Landscape (B, 5-15%) 1,030 0.024
1.4 Landscape (B, >15%) 3,765 0.086
1.5 Permeable Payers 3,874 0.089
18,436 0.423
DMA-1C 4 BIOFILTRATION BASIN 3 POC #1
1.1 Roof/Pavement 21,181 0.486
1.2 Landscape (8, 0-5%) 1,466 0.034
22,647 0.520
DMA-1D4 BIOFILTRATION BASIN .3 POC #1
1.1 Roof/Pavement 13,935 0.320
1.2 Landscape (B, 0-5%) 1,117 0.026
1.3 Landscape (8, 5-15%) 230 0.005
1.5 Permeable Payers 2,312 0.053
17,594 0.404
DMA-1E 4 PROPRIETARY BIOFILT. (MWS) 4 POC #1
1.1 Roof/Pavement 57,558 - 1.321
57,558 1.321
DMA .71 TOTAL 148,710 3,414
DMA-2A 4 SELF-MITIGATING AREA 4 POC #1
2.1 Roof/Pavement 110 0.003
2.2 Landscape (B, 5-15%) 658 0.015
2.3 Landscape (B, >15%) 12,025 0.276
12,793 0.294
DMA-2 TOTAL 12,793 0.294
POC #1TOTAL 161,503 3.709
ATTACHMENT 1C:
HARVESTAND USE FEASIBILITY CHECKLIST (FORM 1-7)
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1-2 February 2016
Appendix I: Forms and Checklists
-
Is there a 1emand for harvested water (check all that apply) at the project site that is reliably presnt during
the wet season?
E] i oilct and urinal flushing
O Landscape irrigation
C] Otheri_________
if there is a demand; estimate the anticipated average wet season demand over a period of 36 hours. Guidance
for planning level demand calculations for toilet/urinal flushing and landscape irrigation is provided .in Section
13.3.2,
Toilet Flushing = 7 gal x 100 employees x 1.5 days= 1,050 gal = 140 cf
Irrigation = 1,470 gal/ac x 0.569 ac = 836 gal = 112 cf
Total 36-Hour Demand = 252 cf
Calculate the D(..V using worksheet B.24.
i)CV = 5,391 (cubic feet))
3a. Is the 36 hour demand greater 3b. Is the 36 hour demand greater than 3c. Is the 36 hour demand
than or equal to the MW U.2SDCV but less than the full 1)CV? less than 0.25DCV?
Yes / i\ \c' / ' \o
Harvest and use appears to be Harvest and use may be feasible. Harvest and use is
feasible. Conduct more derailed Conduct more detailed evaluation and considered to be infeasible.
evaluation and sizing calculations sizing calculations to determine
to confirm that 1)CV can be used feasibility. Harvest and. use may only be
at an adequate rate to meet able to be used for a portion of the site,
drawdown criteria, or (optionally) the storage may need to he
upsized Co meet. long term capture targets
while draining in longer than 36 hours.
Is harvest and use feasible based on further evaluation?
1 Yes, refer to Appendix E to select and size harvest and use I3Ml>s.
iJ. No, select alternate BMPs.
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ATTACHMENT 1D:
INFILTRA11ON FEASIBILITY CHECKLIST (FORM 1-8)
Appendix I: Forms and Checklists
I - 1u11 lnflltr.unti F:i-ihili rtin Criiri;
\\3uld inllltr,ulon f t1w full t1cn uluinc hc I tihlc from a phicul crpcti\: \vlth)ut 111\ ueiruhlc
u(Cl!ji, ihat "111111t H bc reainahl\ ttiaiud
Yes No
— Is the estimated reliable infiltration rate below proposed
facility locations greater than 0.5 inches per hour? the rt ponsc
1 to this Screening Question shall be based on a comprehensive X
evaluation of the factors presented in Appendix C.2 and Appendix
D.
Provide basis:
Per the geotechnical investigation report by GM1.J dated 12/13/19, infiltration rates within the upper 5 feet of
site soils were determined to he 0.02 inch/hour and 0.23 inch/hour (not using a factor of safety), Full Infiltration is
not feasible at the project site due to the presence of engineered fill and dense to very dense formation. See
Geotechnical Investigation Report by GMU attached to this report.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources. etc. Provide narrative
discussion of study/data source applicability.
Can infiltration greater than 0.5 inches per hour be allowed
without increasing risk of geotechnical hazards (slope stability,
2
groundwater mounding, utilities, or other factors) that eatiflot
be mitigated to an acceptable level? The response to this
Screening Question shall be based on a comprehensive evaluation of
the factors presented in Appendix C.2.
Provide basis:
N/A
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability.
1-3 February 2016
Appendix I: Forms and Checklists
us No
Can infiltration greater than 0.5 inches per hour be allowed
without increasing risk of groundwater contamination (shallow
water tables storm. water pollutants or other factors) that cannot
be mitigated to an acceptable level? The response to this
Screening Question. shall be based on a comprehensive evaluation of
the factors presented in Appendix CS.
Provide basis:
N/A
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability.
Can infiltration greater than 0.5 inches per hour be allowed
without causing potential water balance issues such as change
of seasonality of ephemeral streams or increased discharge of
contaminated groundwater to surface waters? The response to
this Screening Question shall be based on a comprehensive
evaluation of the factors presented in. Appendix C.3.
Provide basis:
N/A
Summarize findings of studies; provide reference to studies, calculations, naps, data sources, etc. Provide narrative
discussion of study/data source applicability.
If all answers to rows 1, - 4 are "Yes" a full infiltration design is potentially feasible.
Part 1 The feasibility screening category is Full infiltration
Result 'so ife to oil1. .
would not ecnunljl b yohk <n d. onhk to 1ch 1 "full ntiltt itiofi k se,n
lrud to Put 2
'To be cctmp]cted using gathered site information and best professional judgmeiit considering the definition of .MEP in
the MS4 Pertnh - Additional lusting and/or studies may be required by the City to substantiate findings,
1-4 February 2016
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Appendix I: Forms and Checklists
ri i:l lifi]tr ti, ,v.Xol ritilt rm i i i i I ., i h i Ii S crck, it i ti c ri
\\ otild in1tr.tin I \v;lt(r i ll :tiiv .pte&i. III l( tit)iiii kc ph\ '.ica1! 1Uil)Ic uiIiiut ally n2,lti
:l'l111' that yalinot he rea.nahl 11ii1tcd
Do soil and geologic conditions allow for infiltration in any
appreciable rate or volume? 'Ihe rpolse to this Scrtning
Question shall be based on a comprehensive evaluation of the X
factors presented in Appendix C.2 and Appendix D.
Provide baits:
Per the gcotechnicai investigation report by (;MU dated 12/13/19, infiltration rates within the upper 5 feet of
site soils were determined to be 0.02 inch/hour and 0.23 inch/hour unfactored). Pull infiltration is not feasible at
the project site due to the presence of engineered fill and dense to very dense formation. Sec Geotechnical
Investigation Report by (iMU attached to this report. An averaged infiltration rate or 0.041 in/hr (with factor of
safety = 3) is used for partial infiltration.
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide
narrative discussion of studs,/data sourc apphcibilit and 'ah it was not ttbk to mitigate low infiltration rates.
Can Infiltration in any appreciable quantity be allowed
without increasing risk of geotechnical hazards (slope
( stability, groundwater mounding, utilities, or other factors)
that cannot be mitigated to an acceptable level? The response X
to this Screening Question shall he based on a comprehensive
evaluation of the factors presented in Appendix C.2.
Provide basis:
N/A
Summarize findings of studies; provide reference to studies, calculations, maps. data sources. etc. Provide narrative
discussion of st:uclv/daia source applicability and why it was not feasible to mitigate low infiltration rates.
1-5 February 2016
Appendix I: Forms and Checklists
Can Infiltration in any appreciable quantity be allowed
without posing significant risk for groundwater related
concerns (shallow water table, storm water pollutants or other
factors)? The response to this Screening Question shall be based X
on a comprehensive evaluation of the factors presented in
Appendix C3.
Provide basis:
N/A
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates.
Can infiltration be allowed without violating downstream
8 water rights? The response to this Screening Question shall be x based on a comprehensive evaluation of the factors presented in
Appendix (:3.
provide basis:
N/A
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates.
If ill an sx hc n pith a n i ration deogn i potrntia IF Idt
Part Fhc tdainl i u , Partial Infiltration.
Result* If
- any answer from row 58 is no, then itthltraion of an' volume is considered to be
infeasible within the drainage area. The feasibility screening categc.ry is No Infiltration.
TO be completed using gathered site information and best professional iudgmcnt considering the definition of MEl? ii
the 'S4 Permit. Additional testing and/or studies may be required by the City to substantiate findings.
1-6 February 2016
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Soil assessment methods 0.25 2 0.50
Predominant soil texture 0.25 3 0.75
Suitability. Site soil variabiht 0.25 1 0.25
Assessment Depth to groundwater / imperuous 0 layer 0.25
Suitability .\ssccsnlent Safety Factor, SA IEP 1.75
Level of pretreat menu expected
sediment loads 0.5 1. 0.50
B Design Redundancy/resiliency 0.25 2 0.50
Compaction during COfl>truCtiufl 0,25 1 0.25
Design Safety Factor, Sli ).p 1.25
Combined Safety Factor, S -1 SB 3.0
()bscred Infiltration Rare, inch/hr, l<<4r,,a 0.02 + 0.23 = 0,125
(corrected for test-specific bias) 2
Design Infiltration Rate, in/hr, = / s,. 0.041 in/hr
Suppri n'' I) t.
Briefly describe infiltration Lest and provide reference to test forms:
Per geotechnical report by GMU dated 12/13/19:
"iwo (2) preliminary infiltration tests were performed in general conformance with the County of Sari Diego
Low Impact Development (LID) Uandhook. The infiltration drill holes were excavated to depths ranging from
4 to 5 feet below the existing grade using a hollmv stetmaugcr, truckmounred drill rig.'
The calculated unfactored infiltration rates are 0.02 in/br at 5.0' bgs and 0.23 in/hr at 4.0' bgs.
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Appendix I: Forms and Checklists
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'-7 February 2016 Li
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May 20, 2021
May Patel
Autonation
200 SW 1" Street, 14 Floor
Ft. Lauderdale, FL, 33301 GMU Project 18-101-00
Subject: Partial Infiltration of Unlined Biofiltration Basins
References: Geotechnical Investigation Report, Auto Nation BMW of Carlsbad, 1050 and
1060 Auto Center Court, Carlsbad, California
Dear Mr. Patel:
Per our referenced geotechnical report two preliminary infiltration tests were completed hi general
accordance with the San Diego Low Impact Development (LID) handbook. These tests were
completed at approximately 5 feet below grade. The results presented in our report do not
incorporate a factor of safety. The unfactored rates are 0.02 inches per hour and 0.23 inches per
hour for drill hole locations 6 and 7, respectively. See our referenced report for these drill hole
locations within the site. Although "infiltration" was determined not to be feasible, it is our opinion
that partial infiltration may be considered from a geotechnical perspective for the (2) site unlined
bioflitration basins given that some infiltration was recorded. provided the following:
The infiltration rates contained in our referenced report be utilized for design. How the rates
are utilized in the design shall be solely per the basin designer - i.e. project civil engineer or
hydromodification consultant.
There is an overflow outlet incorporated in the design.
Our specifications for the permeable concrete interlocking vehicular payers with respect to
subgrade preparation are adapted to the unlined biofiltration basins where partial infiltration
is desired.
Respectfully submitted,
MatjIfw T. Farrington M.Sc., PE 90349
Prcect Engineer
Distribution: Aaron Alberts, CDR
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ATTACHMENT 1E:
POLLUTANT CONTROL BMP DESIGN WORKSHEETS/CALCULATIONS
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ATTACHMENT le:
LID DESIGN CAPTURE VOLUME (DCV) CALCULATIONS
Per Appendix B of the City of Carlsbad AMP Design Monual:
DCV 3,630XCXdxA
Q= CXIXA
DCV - Design Capture Volume (cf)
Q - Diversion flow rate (cfs) for off/inc BMP
C = Adjusted ru ioff factor (unitfesc) = (IC A, 14EA )
d 85 ' percentile, 24-hr storm event rainfall depth (in)
A = Tributary area to AMP (ac)
Rainfall intensity - 0.2 in/hr
PROJECT: BMW of Carlsbad
LOCATION: Carlsbad, CA
DATE: 05/21/2021
NOTES:
Impervious - Roof/Pavement IC,=0.901
Pervious 4 Landscape (B), Permeable Payers [C=0.10]
DCV result used for City Worksheets 9.4-1 & 9.5-1
0% of A*CJ
DMA ID Area A
(SF)
Area A
(AC) A (SF) A (SF) A A ( ) - C5A
A5
DCV
(CF)
Minimum
Footprint (58) (CFS)
8iDfiltratiDn Basin WI Partial Retention '3 POC 411
1A 32,474 1 0.746 19,664 12,810 60.6% 39.4% 0.584 917 569 0.087
18 18,436 0.423 8,486 9,951 46.0% 54.0% 0.468 417 259 0.040
50,911 1.169 28,149 22,761 55.3% J 44.7%
f0trat;on basin wl IthrmeabIe
1,335
Bio
Liner-) POC #1 _____
1C 22,647 0.520 21,181 1,466 93.5% 6.5% 01848 928 576 0.088
10 17,594 0.404 13,935 3,659 1 79.2% 20.8% 0.734 624 387 0.059
40,241 0.924 35,116 5,125 1 87.3% 12.7% 1,552
Proprietary Bofiltration (MWS) 4 POC #1
ZA 1 57,558 I 1.321 1 57,558 I 0 I 10D,0% I 00/ 0,900 2,534 554 0.238
57,558 1.321 1 57,558 0 100.05/. 0.0% 2,534
celf-Mitigát n Areas ->POC 411
ZA f_12,793 I 0,294 I 110 I 12,682 I 0.9%99.1%- -
12,793 0.294 110 12,682 0.9'/ 99.1%
TOTAL 1 161,503 3.708 120,934 40,568 74.9% 25.1% 0.699 5,391 3,387
Leg rd
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Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods
N
\
N N z 1
/ N
N \
\
\ N
San Diego County
85 th Percentile lsopluvials
' \
-
\\N
z;/ H111'\\\ \
N
/
UU
+ ---a-- - -
+ — — -
+ GS --
Figure B.1-1: 85th Percentile 24-hour isopluvial Map
B-5 February 2016
DMA-IA: Biofiltration wl Partial Retention
(Structural BMP-I)
Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods
Worksheet B.5-1: Simple Sizing Method for Biofiltrafion BMPs
RemainingDCVaftcr.impnen6ngrtionBM13s 917 cic-feet
Partial Retention
2 Infiltration rate from Form 1-9 if partial infiltration is feasible 0.041 in/hr.
3 Allowable drawdown time for aggregate storage below the underdrain 36 hours
4 Depth of runoff that can be infiltrated [Line 2 < Line 3] 1.48 inches
5 Aggregate pore space 0.40 in/in
6 Required depth of gravel below the underdrain. [Line 4/ Line 5.1 3.69 inches
7 Assumed surface area of the biofiltration BMP 812 sq-ft
8 Media retained pore storage 0.1. in/in
9 Volume retained by BMP [[Line 4 ± (Line 12 x Line 8)]/121 x Line 7 242 cubic-feet
10 DCV that requires biotiltration [Line I — Line 9] 675 cubic-feet
BMP Parameters
ii 1 Surface Ponding 1.6 inch minimum, 12 inch maximum] 6 inches
12 Media Thickness [18 inches minimum], also add mulch layer thickness to
. . this line for sizing calculations 18+3=21 inches
13 Aggregate Storage above underdrain invert (12 inches typical) use 0
inches for sizing if the aggregate is not over the entire bottom surface area 3 inches
14 Media available pore space 0.2 in/in
15 Media filtration rate to be used for sizing (5 in/hr. with no outlet control;
if the filtration is controlled by the outlet, use the outlet controlled rate) in/hr.
Baseline Calculations
16 Allowable Routing 1'inie for sizing 6 hours
17 Depth filtered during storm [line 15 x line 16] 30 inches
18 Depth of Detention Storage ' 12.6 inches
-
[Line 11 + (Line 12 x Line 14) + (Line 13 x Line 5)]
19 Total Depth Treated [Line 17 + line 181 . 42.6 inches
2p,tion l — Biofilter 1.5 times the DCV
20 Required biofiltered volume [1.5,x Line 101 1,013 cubic-feet
21 Required [Line 20/ Line 191 x 12 285 sq-ft _Footprint
2 SIOTL 0.775 of rrnarnrng DCV_mpw5 incpunding
22 1 Required Storage (surface + pores) Volume [0.75 x line 10] 506 cubic-feet
23 RequiredFootprint [Line 22/ Line 18] x 12 482 sq-ft
Footprint of the BMP
24 Area draining to the BMP 32,474 sq-ft
25 Adjusted Runoff Factor for drainage area (Refer to Appendix B.1 and 13.2) 0.584
26 Minimum BMP Footprint [Tine 24 x Line 25 x 0.031 569 sq-ft
27 Footprint of the BMP = l\1 ximum'1inimum(Line 21, Line 23), Line 26) 569 sq-ft
Note: line 7 is used to estimate the amount of volume retained by the B.M.P. Update assumed surface area in Line 7 until
its equivalent to the requited bioltration footprint (either Line 21 or Line 23
B-26 February 2016
DMA-113: Biofiltration wl Partial Retention
(Structural BMP-2)
Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods
Worksheet B.5-1: Simple Sizing Method for Biofiltration BMPs
I Remaining DCV after implementing re Hon BMP - cubic-feet
Partial Retention
2 Infiltration rate from Form 1-9 it partial infiltration is feasible 0.041 in/hr.
3 Allowable drawdown time for aggregate storage below the undcrdrain 36 hours
4 Depth of runoff that can be infiltrated [Line 2 x Line 31 1.48 inches
5 Aggregate pore space 0.40 in/in
6 Reqinred depth of gravel below the undcrdrain lIme 4/ Line 5] 3.69 inches
7 Assumed surface area of the biofiltration BMP 359 sq-ft
8 Media retained pore storage 0.1 in/in
9 Volume retained by BMP fl1tne 4 ± (Line 12 x Line 8)1/121 x Line 7 107 cubic-feet
10 DC\' that requires biofiltration [Line I --Line 91 310 cubic-feet
U \1 I' Parameters
Ii Surface Ponding [6 inch minimum, 12 inch maximum] 6 inches
12 Media Thickness [18 inches minimum], also add mulch layer thickness to
-
. this line for sr/ing calculations 18+3=21 inches
13 Aggregate Storage above underdrain invert (12 inches tpical) - use 0
-
. inches for swing if the aggregate is not over the entire bottom surface area 6 inches
14 Media available pore space 0.2 in/in
15 Media filtration rate to be used for si'ng (3 in/hr. with no outlet control;-
' - it the filtration is controlled by the out let- use the outlet controlled rate) in/hr.
Bascliin Calculations
16 Allowable Routing Time for si/ing 6 hours
17 Depth filtered during storm ]1 inc 15 x line 16] 30 inches
18
1.
Depth of Detention Storage
inches [Line 11 + (Line 12 x Line 14) + ine 13 x 5)] 12.6
19 Total 1)cpth Treated ]Linc 17 + Line 181 42.6 inches
Option 1-- Biofilter 1.5 tinies the DCV
20 Required biofiltered volume [1.5,x Line 101 465 cubic-feet
21 Required Footprint [Line 20/ Line 19] x 12 135 sq-ft
ption_2- Store 0.75 of renlaining 1)CV in prc. and pondin!
-
22 Required Storage (surface + pores) Volume [0.75 x Line 101 233 cubic-feet I
23 Required Footprint ILine 22/ Line 181 x 12 [ 222 sq-ft
Footprint of the BMP
24 1 Area draining to the BMP 18,436 sq-ft
25 Adjusted Runoff I 'actor for drainage area (Refer to Appendix B.1 and B.2) 0.468
26 Minimum BMP Footprint jLine 24 x Line 25 x 0.03] 259 sq-ft
27 1 ootprint of the BMP = MaximumMinimum(Line 21, Line 23), line 26) 259 s1-ft
Note: Line] is used to estimate the amount of volume retained by the BMP. Update assumed surface area in Line] until
its equivalent to the required biofiltrition footprint (either Line 21 or Line 23
B-26 February 2016
VARIES PER PLAN
BMP-1 & BMP-2: BASIN CROSS-SECTION (TYR)
(NT.S.)
WALL WALL
FREEBOARD
16 PONDING
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F
3.33
mv
3 MULCH
IS AMENDED SOIL
3 SAND (FILTER)
3 PEA GRAVEL (FILTER)
7" GRAVEL (STORAGE)
/
PVC UNDERDRAIN
CLEANOUT OR SQUARE RISER
CLEAN OUT (CO.) DETAIL
(N.TS.)
------------ NOTE: UNDERDRAIN ENTERS
RISER AT ONLY 1 (ONE) SIDE.
RISER
HC
SLOTTED
PVC UNDERDRAIN
BMP-2 BMP-1
BMP RISER OUTLET DETAIL
(N.T.S)
~GPEATER THAN U
WI DRILLED HOLE
LL 4 WDIAOPENING
UNDERDRAIN = BOTTOM OF BASIN
FLOW CONTROL ORIFICE PLATE
6 DIA, SLOTTED 7ER 1VALL FLOW CONTROL PVC UNDERDRAIN OR PLATE.
EE DETAIL ABOVE
FILTER &
GRAVEL
STORAGEJ - B DIA. ORIFICE
7 JI
BMP-i & BMP-2: LID ORIFICE DETAIL
(N.T.S.)
BMP-1 & BMP-2: PLACEMENT OF UNDERDRAIN DETAIL
(NT.S.)
BIOFILTRATION WI PARTIAL RETENTION
BMP-1 & BMP-2: UNDERDRAIN & RISER OUTLET LOCATION DETAIL
(N.TS.) CiPtResources
Commercial
Development
TyG Woos. Tororc.w's Reality-
,
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DMA-IC: Biofiltration Basin
(Structural BMP-3)
Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods
Worksheet B.5-1: Simple Sizing Method for Biofiltration BMPs
I Remaining DC\' atter implementing retention BMPs 928 cubic-feet
Partial Retention
2 lnfiitration rate from I arm 1-9 if partial infilt;. )fl is feasible 0 in/hr.
Allowable drawdown time for aggregate storage below the underdrain 36 hours
4 Depth of runoff that can be infiltrated Il.ine 2 x line 3] () inches
5 Aggregate pore, space 0.40 in/in
6 Required depth of grave] below the underdrain [Line 4/ Line 5] 0 inches
7 Assumed surface area of the biofihtration 13MP 576 sq-ft
8 Media retained pore storage 0.1 in/in
9 Volume retained by BMP IlLine 4 4- (Line 12 x Line 8)1/121 x Line 7 101 cubic-feet
10 DC\' that requires bioliltration [Line I - Line 9]
Parameters
828 cubic-feet
BMP
ii TSurfice Ponding 16 inch minimum, 12 inch maximum] 6 inches
12 Media 1 hickness [18 inches minimum], also add mulch layer thickness to
. . this line for sizing calculations 18+3=21 inches
13 \g.grcgate Storage above underdrain invert (12 inches typical) - use (1
inches inches for sizing if the aggregate is not over the entire bottom surface area 6
14 Media available pore space 0.2 in/in
15 Media filtration rate to be used for sizing (5 in/hr. with no outlet control; -
.
if the filtration is controlled by the outlet, use the outlet controlled rate)
Ili/hr./hr.
1Ltdiiie Ca1eulititin.,
16 Allowable Routing Timc for sizing 6 hours
1.7 1)epth filtered during storm [Line 15 x I inc 161 30 inches
1$ Depth of Detention Storage . inches [Line 11 + (Line 12 x Line 14) + (Line 13 x line 5)] 12.6
19 Total Depth Treated ]Line 17 + Line 181 42.6 inches
Option 1 - Rinlilter 1.3 times the Dc\
20 Required biofiltered volume 11.5 x Line 10] 1,241 cubic-feet
21 Required Footprint [Line 20/ Line 191 x 12 350 sq-ft
Option_2 "ton. 0.7 5 of remaining DC in pores sndponding
22 Required Storage (surface + pores) Volume ]0.75 's Line 10] 621 cubic-feet
23 Required Footprint ILine 22/ Line 11 x 12 591 sq-ft
I to) orprint of the BMP
24 Area draining to the BMP 22,647 sq-ft
25 Adjusted Runoff Factor for drainage area (Refer to Appendix 13.1 and 13.2) 0.848
26 Minimum BMP Footprint ]Line 24 x Line 25 x 0.03] 576 sq-ft
27 Footprint of the BMP = MaxirnumMinimumLine 21, Line 23), Line 26) 576 sq-ft
Note Line - is used to estimate the amount of volume retained by the BMP 1 Pilate assumed surface area in Line 7 until
its equivalent to the required bioMiration footprint (either Line 21 or line 23)
B-26 February 2016
DMA-ID: Biofiltration Basin
(Structural BMP-4)
Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods
Worksheet B.5-1: Simple Sizing Method for Biofiltration BMPs
I Rernainina DCV mplcrncnting retention 13MPs 624 cubic-feet
P.irnal Retention
2 infiltration rate from Form 1-9 if partial infiltration feasible 0 in/hr.
3 Allowable drawdon time for aggregate storage below the underdrain 36 hours
4 Depth of runoff that can be infiltrated tine 2 x Line 31 0 inches
5 Aggregate pore space 0.40 in in
6 Required depth of grave] below the underdrain [Line 4/ Line 5] 0 inches
7 Assumed surface area of the biofiltratinn 13\IP 455 sq-ft
8 Media retained pore storage 0.1 in/in
9 Volume retained by BMP flLinc 4 + (J..ine 12 x Line 8)1/121 x l.nw 7 80 cubic-feet
10 DCV that requires biofiltration inc I -Line 9] 544 cubic-feet
U \1 P Parameters
11 .urfacc Ponding [6 inch nhinilmirn, 12 Hch max1n im[ 6 inches
12
-
Media Thickness [18 inches minimum[, also add mulch layer thickness to
. . . this line for su'ing calculations 18+3=21 inches
13 Aggregate Storage above underdrain invert (12 inches typical) — use 0
i nches for sizing if the aggregate is not over the entire bottom surface area 6 inches
14 Media available pore space 0.2 in/in
15
16
B.t'clinc
Media filtration rate to be used for sizing (5 in/hr. with no outlet control;
. . the filtration is controlled by the outlet, use the outlet controlled rate)
Calculations
Allowable Routing Time tot sizing
in/hr.ii
-
6 hours
17 Depth filtered during storm [Line 15 x i.ine 161 30 inches
lb Depth. of 1)crention Storage
[Line 11 + (Line 12 x Line 14) + (Line 13 x Line 5)] 12.6 inches
19 Total l)eprh Treated ILine 17 + Line 181 42.6 inches
Option 1— Uioffltcr 1.5 time'. the DC\
20 Required biofiltered volume 11.5 x Line lQJ 816 cubic-feet
21 Required Footprint [Line 20/ Line 191 x 12 230 sq-ft
Option 2 - Store 0.75 of rcniainini DCV in pure' kind pondin
22 Required Storage (surface + pores) \'olume [0.75 x Line 101 408 cubic-feet
23 Required footprint ILinc 22/ Line 181 x 12 389 sq-ft
Footprint of the BMP
24 Area draining to the BMP 17,594 sq-ft
25 Adjusted Runoff Factor for drainage area (Refer to Appendix 13.1 and 13.2) 0.734
26 Minimum BMP Footprint [Line 24 x Line 25 x 0.031 387 s(4-ft
27 1 'ootprint of the BMP = MaximumMimmumLine 21, Line 23), Line 26) 387 sq-ft
Note: Line 7 is used to estimate the amount of volume retained by the BMP. Update assumed surface area in Line 7 until
its equivalent to the reqw.red biolltr4tion footprint (either Line 21 or Line 23)
B-26 February 2016
BMP-3 & BMP-4: PLACEMENT OF UNDERDRAIN DETAIL
(N.T.S.)
a
a
BMP RISER OUTLET DETAIL
(N.T.S.)
SCREW CAP
CLEANcDUT OR SQUARE REA
CLEAN OUT (C.O.) DETAIL
(N.T.S.)
BMP-3 & BMP-4: UNDERDRAIN & RISER OUTLET LOCATION DETAIL
(N.T.S)
I
VARIES PER PLAN RETAINING RETAINING
WALL \ WALL 35<3 RISER
- —(25<2 INTERNALLY) - - - - - - - - 4' FREEBOARD
i 6' PONDING
:4
/ - 3' MULCH
/
3.251 . N 18 AMENDED SOIL
- , - 3' ND (FILTER)
PEA GRAVEL (FILTER)
6 GRAVEL (STORAGE)
PIPE
IMPERMEABLE
LINER, SEE NOTES
NOTE:
SLOTTED UNDERDRAIN AND ORIFICE OUTLET NOT SHOWN
IMPERMEABLE LINER TO BE 30 MIL GSE HD SMOOTH LINER FROM
GSE ENVIRONMENTAL OR APPROVED EQUIVALENT
BMP-3 & BMP-4: BASIN CROSS-SECTION (TYP.)
(N.T.S.)
"J- GREATER THAN U
Wi DRILLED HOLE
I X'DIA, OPENING
ULNU1UP1I' = bU I I UM
FLOW CONTROL ORIFICE PLATE
FILTER &
SEE DETAIL ADO
GRAVEL
STORAGE DIA. ORIFICE
BOTTOM OF BASIN NATURAL
IMPERMEABLE LINER SOIL
BMP-3 & BMP-4: LID ORIFICE DETAIL
(NVT.S.)
AMENDED
SOIL MEDIA SLOTTED
PVC UNDERORAIN
3" SAND FILTER COURSEJ PEA GRAVEL
GRAVEL STORAGE 6"
IMPERMEABLE LINER AT 8 OM OF BASIN
TO BE 30 MIL GSE HD SMOOTH LINER BY GSE SOIL ENVIRONMENTAL OR APPROVED EQUIVALENT
BIOFILTRATION BASIN
C Commercial
Development
Resources
Today deas. Tomorrow's Reality
4fl W •mii
DMA-1 E: Proprietary Biofiltration (MWS)
(Structural BMP-5)
Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods
Worksheet B.5-1: Simple Sizing Method for Biofiltration BMPs
Remaining DCV after implementing retention BMPs 2,504 cubr feet
Partial Retention
2 h1filtration rare from Form 1-9 if partial infiltration is feasible 0 in/hr.
3 Allowable drawdown time for aggregate storage below the underdrain 36 hours
4 Depth of runoff that can be infiltrated Sine 2 ' Line 3] _(I 0 inches
5 Aggregate pore Space 0.40 in/in
6 Required depth of gravel below the underdrain [Line 4/Line 5] 0 inches
7 Assumed surface area of the biofiltrarion BMI' 1,554 sq-ft
8 Media retained pore storage 0.1 in/in
9 Volume retained by BMP [(Line 4 + (Line 12 x Line 8)1/121 x Line 7 0 cubic-feet
10 DCV that n iuires 1)1 ihration 1 inc I Line 91 2,504 cubic-feet
U \1 P P:ir,imctcr'-
11 Surface Ponding 16 irch minimum, 12 inch maximum.] 6 inches
12 Media 'thickness [18 inches Ininimuni(, also add mulch layer thickness to
-
. . this line for sizing calculations 18+3=21 inches
Aggregate Storage above underdrain invert (12 inches typical) - use 013 inches for sizing if the aggregate is not over the entire bottom surface area inches
14 Media available pore space 0.2 in/in
15 Media filtration rate to be used for sizing (5 in/hr. with no outlet control; -
if the titration is controlled by the outlet, use the outlet controlled rate) in /hr.
R.t..iine C.ticu1.iiion'
16 1 Allowable Routing lime for sizing 6 hours
17 Depth filtered during storm [Line 15 x Line 16] 30 inches
lb Depth. of Detention Storage inches (line 11 + (Line 12 x Line 14) + (Line 13 x Line 5)] 13.8
19 lotal Depth Treated ILine 17 + Line 181 43.8 inches
Upthni 1 - Biolilter 1.5 times the DCV
20 Required bi.filtered volume (1.5 x Line 10( 3,756 cubic-feet 1
21 Required Footprint [Line 20/ Line 19] x 12 1,029 sq-ft
Option 2 - Store 0.75 of remaining DCV in pores and poiiding
22
[
Required Storage (surface + por(.,-s) Volume [0.75 x Line 10] 1,878 cubic-feet
23_Required footprint ILine 22/ Line 18] x 12 1,633 sq-ft
Footprint of the B\1P
24 Area draining to the BMP 57,558 sq-ft
25 Adjusted Runoff Factor for drainage area (Refer to Appendi:. BA and B.2) 0.90
26 Minimum BMP Footprint (line 24 x Line 25 x 0.03( 1,554 sq-ft
27 Footprint of the liMP = Maximurn(Minimum(Line 21, Line 23), Line 26) 1,554 sq-ft
Note: Line 7 is used to estimate the amount of volume retained by the BMP. Update assumed surface area in Line 7 until
its equivalent to the reeuired biofiltration footprint (either Line 21 or Line 23
B-26 February 2016
Appendix B: Storm Water Pollutant Control Hydrologic Calculations and Sizing Methods
B.6.3 Sizing Flow-Thru Treatment Control BMPs: Use for Sizing
Proprietary Biofiltration BMP
Flow-th.ru treatment control BMPs shall be sized to filter or treat the maximum flow rate of runoff
produced from a rainfall intensity of 0.2 inch of rainfall per hour, for each hour of every storm event.
The required flowth.ru treatment rate should be adjusted for the portion of the i)CV already retained
or biofiit.ered onsite as described in Worksheet 13.6-I.. The following hydrologic method shall be used
to calculate the flow rate to be filtered or treated:
Q = C x i x A
Where:
Q = Design flow rate in cubic fret per second
(. = Runoff factor, area-weighted estimate using Table BA-I
= Rainfall intensity of 0.2 in/hr.
A = Tributary area (acres) which includes the total area draining to the BMP, including any
offsite or onsite areas that comingle with project runoff and drain to the BMP. Refer to Section
3.3.3 for additional guidance. Street projects consult Section. 1.4.2,
Worksheet B.6-1: Flow-Thru Design Flows
EMEMIM:8 vim OEM _
1 I DCV I)CV 2,504 cubic-feet
2 l)CV retained DC 0 cubic-feet
3 I)CV biofihered IXNWOfiftemd 0 cubic-feet:
I)CV requiring flow-thru 4 . . .
(Line I -Line 2-0.67xLine 3)
DC\ ro.Thtu 2,504 cubic-feet
5 Adjustment factor (Line 4 / line I)* .A.F I unitless
6 Design. rainfall intensity i (.).20 in/hr
7 Area_tt1iP(s) A— 1.321 acres
Area-weighted runoff factor (estimate using S s
.
-
Appendix B.2)
C 0.9() unitless
9 Calculate Flow Rate = AF x (C x I x A) 0.238 cfs
*Adjustment factor shall be estimated considering only retention and hiofiltration BMPs located upstream of
flow-thru BMPs. That is, if the flow-thru BMP is upstream of the project's retention and biofiltration BMPs
then the flow-thru BMP shall be sized using an adjustment factor of 1.
DMA-i E: Proprietary Biofiltration (MWS)
(Structural BMP-5)
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B-36 February 2016
I
9,-0-
ELEVATION VIEW RIGHT END VIEW
VERJ7C4L-N --I ,—WLILAMVMU
UNDERORAIN _______ :.. . BED
MANIFOLD PAT ,-ENTED
4 PL1YMETL7?
VOID AREA
'
,-PRE--F1LTER
rI CARTRIDGE
0
LEFT END VIEW
OUTLET PIPE -1 I I '-INLET PIPE
SEE NOTES L0PJJN DO$W LINE SEE NOTES
PLAN VIEW
FLOW COOL
RISER
IE IN
PEAK HUL
121 a LOU a
1.
—VEGETATION
PL4NT
ESTABLISHMENT
MED/A
"-6"
I
I
SITE SPECIFIC DATA
PROJECT NUMBER 8709
ORDER NUMBER
PROJECT NAME BMW OF CARLSBAD
PROJECT LOCATiON CARLSBADD, CA
STRUCTURE ID MWS UNIT
TREATMENT REQUIRED
VOLUME BASED (CF) FLOW BASED (CFS)
N/A 0.239
TREATMENT HGL AVAILABLE (Fr) N/A
PEAK BYPASS REQUIRED (Cr5) - IF APPLICABLE 7.62
PIPE DATA I.E. MATER/AL D/AMETER
INLET PIPE 1 90.57 N/K N/K
INLET PIPE 2 N/A N/A N/A
OUTLET PIPE 87.57 N/K N/K
PRETREATMENT B1OF1L IRA T/ON DISCHARGE
RIM ELEVATION 93.15 93.15 93.15
SURFACE LOAD PEDESTRIAN N/A PEDESTRIAN
FRAME & COVER 1 030" OPEN PLANTER 024"
WE/L4NDMEDi4 VOLUME (cv) 5.57
ORIFICE SIZE (0/A. INCHES) T-02. 19"
NOTES: PRELIMINARY NOT FOR CONSTRUCTION. EOW TO PROI'YDE
FOOTiNG DETAILS.
INSTALLATION NOTES
CONTRACTOR TO PROVIDE ALL LABOR, EQUIPMENT, MATERIALS AND
INCIDENTALS REQUIRED TO OFFLOAD AND INSTALL THE SYSTEM AND
APPURTENANCES IN ACCORDANCE WITH THIS DRAWING AND THE
MANUFACTURERS SPECIFICATIONS, UNLESS OTHERWISE STATED IN
MANUFACTURERS CONTRACT.
UNIT MUST BE INSTALLED ON LEVEL BASE. MANUFACTURER
RECOMMENDS A MINIMUM 6" LEVEL ROCK BASE UNLESS SPECIFiED BY
THE PROJECT ENGINEER. CONTRACTOR IS RESPONSIBLE TO VERIFY
PROJECT ENGINEERS RECOMMENDED BASE SPECIFICATIONS.
CONTRACTOR TO SUPPLY AND INSTALL ALL EXTERNAL CONNECTING
PIPES. ALL PIPES MUST BE FLUSH WITH INSIDE SURFACE OF
CONCRETE (PIPES CANNOT INTRUDE BEYOND FLUSH). INVERT OF
OUTFLOW PIPE MUST BE FLUSH WITH DISCHARGE CHAMBER FLOOR.
ALL PIPES SHALL BE SEALED WATER TIGHT PER MANUFACTURERS
STANDARD CONNEC77ON DETAIL.
CONTRACTOR RESPONSIBLE FOR INSTALLATION OF ALL RISERS,
MANHOLES, AND HATCHES. CONTRACTOR TO GROUT ALL MANHOLES AND
HATCHES TO MATCH FINISHED SURFACE UNLESS SPECIFIED OTHERWISE
VEGETATION SUPPLIED AND INSTALLED BY OTHERS. ALL UNITS WITH
VEGETATION MUST HAVE DRIP OR SPRAY IRRIGATION SUPPLIED AND
INSTALLED BY OTHERS.
CONTRACTOR RESPONSIBLE FOR CONTACTING BIO CLEAN FOR
ACTIVATION OF UNIT MANUFACTURERS WARRANTY IS VOID WITH OUT
PROPER ACTIVATION BY A BIO CLEAN REPRESENTATIVE.
GENERAL NOTES
INTERNAL BYPASS DISCLOSURE:
THE DESIGN AND CAPACITY OF THE PEAK CONVEYANCE METHOD TO BE REViEWED
AND APPROVED BY THE ENGINEER OF RECORD. HGL(S) AT PEAK FLOW SHALL BE
ASSESSED TO ENSURE NO UPSTREAM FLOODING. PEAK HGL AND BYPASS
CAPACITY SHOWN ON DRAWING ARE USED FOR GUIDANCE ONLY
MANUFACTURER TO PROL'7DE ALL MATERIALS UNLESS OTHERWISE NOTED.
ALL DIMENSIONS, ELEVATIONS, SPECIFiCATiONS AND CAPACITIES ARE SUBJECT TO
CHANGE FOR PROJECT SPECIFIC DRAWINGS DETAILING EXACT DIMENSIONS, WEIGHTS
AND ACCESSORIES PLEASE CONTACT SIC CLEAN.
Priority Development Project (POP) SWQMP
BMW of Carlsbad amobwnwt
ATTACHMENT 2
BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES
[This is the cover sheet for Attachment 2.]
Indicate which Items are Included behind this cover sheet:
Attachment Contents Checklist Sequence
- -- - -- --
Included
Attachment Hydromodification Management See Hydromodification Management 2a Exhibit (Required) Exhibit Checklist on the back of this
Attachment cover sheet.
Exhibit showing project drainage
boundaries marked on WMAA
Critical Coarse Sediment Yield
Management of Critical Coarse Area Map (Required)
Sediment Yield Areas (WMAA Optional analyses for Critical Coarse
Attachment Exhibit is required, additional Sediment Yield Area Determination:
2b analyses are optional) o 6.2.1 Verification of Geomorphic
See Section 6.2 of the BMP Design Landscape Units Onsite
Manual. 0 6.2.2 Downstream Systems
Sensitivity to Coarse Sediment
0 6.2.3 Optional Additional
Analysis of Potential Critical
Coarse Sediment Yield Areas
Onsite
Geomorphic Assessment of
Attachment Receiving Channels (Optional) Not performed
2c See Section 6.3.4 of the BMP Design 0 Included
Manual.
Flow Control Facility Design and
Structural BMP Drawdown Included Attachment Calculations (Required) 0 Submitted as a separate stand- 2d
See Chapter 6 and Appendix G of alone document
the BMP Design Manual
POP SWQMP 23 of 27
Priority Development Project (PDP) SWQMP COMAWKW
BMW of Carlsbad
Use this checklist to ensure the required Information has
been included on the Hydromodification Management Exhibit:
The Hydromodification Management Exhibit must identify:
Underlying hydrologic soil group
Approximate depth to groundwater
Existing natural hydrologic features (watercourses, seeps, springs, wetlands)
Critical coarse sediment yield areas to be protected (if present)
Existing topography
Existing and proposed site drainage network and connections to drainage offsite
Proposed grading
Proposed impervious features
Proposed design features and surface treatments used to minimize imperviousness
Point(s) of Compliance (POC) for Hydromodification Management
Existing and proposed drainage boundary and drainage area to each POC (when
necessary, create separate exhibits for pre-development and post-project conditions)
Structural BMPs for hydromodification management (identify location, type of BMP, and
size/detail)
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PDP SWQMP 24of27 I
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HYDROMODIFICATION MANAGEMENT EXHIBIT
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AC 004 MNI - f / PREPARED FOR PREPARED BY
- I
AUTONA
200SW1STSTREET, 14THROO
rORruD. Commercial
/ COtTAGT: GU: ro\..LL
- - TEL: (954} 769-6XO C Resources
AUTOCENTERCT /
I
SWQMPATTAHMENT 2,4:
HMP EXHIBIT
BMW OF CARLSBAD
1060 AUTO CENTER COURT
CARLSBAD, CA 92008
-. 4'A 1-41-30 I0'I91 '.44.11 .14. 04.101(01111
.10(1 134410, III (311<10(447,
('4, 4/'44 14'I "OIl-A (41011
3341
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all PjAIT
'0 A r 1013(1(1 .. 4. 11.11044(41-I
1045
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243011..
3.01,1 A1I5A44.1.Ls 44.
1.11'00,1141,1-'21'l, 01441-AOl 4414.., <(4101104
41111301,'(1'2T CF 01 C4'TTA 0r'r'2'AflOI'S
.-------------------------------------------------------------14
BMP-0
4.
A
A lJ.'14,114N$AM,...lA RZiot, (113141 It
040' lIt' 10
/
/
BMP-4 BMP-2 BMP-I
UAilN HMP RISER & SLOTTED UNDERDR,I,JN C.O.LAYOUT
0
. I
2 I
M'oL IJ Q.I. /'b LITI. 1011 41410 02 4101*.
EON 011DI0 / SEE 'IE 4(14*00
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- -' / 0 ol'S330U,o
A 24'0(k30FE 4 THPIJMETAA,PLATE 4
411010107*. E(I'EEDCED 1,Ci"CRE'FW4i,1
'3. Di' 00130105 '.151, t4ft........
FLOW CONTROL ORIFICE PLATE
ME
'F ------
2,04
CONCRETE 410114 41-411.
Tr Tr
I
RR INFORMATION ] STUB INFORMATION STUB INFORMATION
BMP-6A
WEST OF PROPOSED BUILDING 1
41(4
BMP-6B
NORTH OF PROPOSED BUILDING
RISER INFORMATION
LI
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414L42-
At'4rDS1VS44
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010410
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TAD. 'IA004S:C4.l0 1(34.4*04*413 _4* 44.0(4(45 4A014401100)40 r(44144.01e.01 i-t005t0tA(10004131100lLtC14000010*04 300 L*oOrI004I044i'T .Ir.ilFOYAPAi1Oli0S 1(40114414.0 200.L10044*1000040E4'0A4At011003ot0440ltsoiotp8000SuPA*0000044.
(04.04.4.3 I0010EAt410Tht Flatoow0(Th
PIPE STORAGE 5,681 CF
DIAMETER 98
MAIM PIPE GAGE 16
WALL TYPF - SOLID
ASSEMBLY
Er
STORAGE sal OF
lIPS
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CORRUGATION 5xi
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I NTECH HTEff 960 UNDERGROUND DETENTION SYSTEM 617515-010 ll LJ4(0ND1 cNTECH 960 UNDERGROUND DETENTION SYSTEM 617515-020 _______________________
ooi ..'....I I 6I6G8oa SOWT1OI60 LLC 044. OETRNTO* TISTEMS BMW CARLSBAD s000ess sow000s *c cospopsaros sysosoos BMW CARLSBAD I
- CARLSBAO,CA
SITE DESIGNATION BMP BA
.0*0
14140 14ISAN •04
CARLSBAD,CA
SITE DESIGNATION BMP 6B
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.04.1 ' 0AA'(A.,jliI"1AII'.*4lA(4.11.4I"ll'CI Ill- 1,11 110040 '.' . 1 2921<41*1'
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OuT_El DETAIL UNDEADRAIN
BMP-'I & BMP-2: BIOFILTRATION BASIN BMP ,3 a BMP 4 BIOFILTRATION BASIN CLEANOUT (CO) DETAIL
WI PARTIAL RETENTION W/ IMPERMEABLE LINER
NOTES:
I, SUP-fIR AND BMP 66TO ACT AS ONE DETENTION
SYSTEM THAT IS HYORAULICALY CONNECTED VA 12' AI-
HOPE PIPE REID SET AT ONE ELEVATION.
2 BMP-6 ,AIHAU. HAVE A MINIMUM. 0A1 STORAGE
(i1IMOa I04400LFT 'N4.LL_ I V C 4,01 . : fOFPI'LCAW 410110 A
DETEIII(i0NVAiJ1..T (IIA,lI-'-loll)
OUTLET STRUCTURE & WEIR DETAIL
SHEET 02 OF 02
PREPARED FOR: PREPARED BY:
AUTONATION INC.
200 SW 1ST STREET, 1411-I FLOOR
P00411 LAUDERDALE, FL 3230l Commercial
cl:I~Resources
CONTACT CUFF POWELL. Development
TEL: (954) 713011-01000
1100?, 414.,. 11.41llA.1111-41214.
41215044(11,70.14(1 141.flA(4*0444.4.14,
SWQMPATTACHMENT 2.4:
lIMP EXHIBIT
BMW OF CARLSBAD
1060 AUTO CENTER COURT
CARLSBAD, CA 9208
ATTACHMENT 2B:
WMAA EXHIBIT
I — — I M — — I — —
t.J1fII:1
t Potential Critical Coarse Sediment Yield Areas ..+
Carlsbad Watershed HU 904 00 211 m12 Exhibit DaleSept.8 2014
ATTACHMENT 2C:
NOT INCLUDED
ATTACHMENT 2D:
TECHNICAL MEMORANDUM:
SWMM Modeling for
Hydromodification Compliance of:
BMW Carlsbad
Prepared For:
CDR
Prepared by;
Luis P.ujra. Phi), (:Ps\\(., ToR, D.WRE.
I R.C.E. 6637
t;\ UZI&/
'OE 66377
*\ EXP 6/3Q/2( 'y
V
Oi CM'7
REC Consultants
2442 Second Avenue
San Diego, CA 92101
Telephone: (619) 232-9200
TECHNICAL MEMORANDUM
TO: CDR,
FROM: Luis Parra, PhD, PE, CPSWQ, ToR, D.WRE, CFM.
David Edwards, MS, PE, CFM.
DATE: December 13, 2019
RE: Summary of SWMM Modeling for Hydromodification Compliance for BMW Carlsbad,
City of Carlsbad, CA.
INTRODUCTION
This memorandum summarizes the approach used to model the proposed commercial site in the City of
Carlsbad using the Environmental Protection Agency (EPA) Storm Water Management Model 5.0
(SWMM). SWMM models were prepared for the pre and post-developed conditions at the site in order
to determine if the proposed LID HMP bio-filtration and underground detention facilities have sufficient
volume to meet Order R9-2013-001 requirements of the California Regional Water Quality Control
Board San Diego Region (SDRWQCB), as explained in the Final Hydromodification Management Plan
(HMP):, dated March 2011, prepared for the County of San Diego by Brown and Caldwell.
SWMM MODEL DEVELOPMENT
The BMW Carlsbad project proposes a commercial structure and servicing parking lots on the currently
develcped site. Two (2) SWMM models were prepared for this study: the first for the predevelopment
and the second for the post-developed conditions. The project site drains to one (1) Point of Compliance
(POC-1) located at the existing storm drain system located to the north of the project site.
Per Section G1.2 in Appendix G of the 2016 City of Carlsbad BMP Design Manual, the EPA SWMM model
was used to perform the continuous hydrologic simulation. For both SWMM models, flow duration
curves were prepared to determine if the proposed HMP facilities are sufficient to meet the current
HMP requirements.
The inputs required to develop SWMM models include rainfall, watershed characteristics, and BMP
configurations. The Oceanside Gage from the Project Clean Water website was used for this study since
it is the most representative of the project site precipitation due to elevation and proximity to the
project site.
Per the California Irrigation Management Information System "Reference Evaporation Zones" (ClMIS
Elo Zone Map), the project site is located within the Zone 1 Evapotranspiration Area. Thus
evapotranspiration vales for the site were modeled using Zone 1 average monthly values from Table
G.1-1 from the 2016 BMP Design Manual. Per the site specific geotechnical investigation and NRCS Web
Soil Survey, the project site is situated upon Class B soils. Soils have been assumed to be compacted in
the existing developed condition while fully compacted in the post developed conditions. Other SWMM
inputs for the subareas are discussed in the appendices to this document, where the selection of
parameters is explained in detail.
BMW Carlsbad HMP Memo
December 13, 2019
HMP MODELING
PRE DEVELOPED CONDITIONS
The current site consists of a developed lot that drains via overland flow to the receiving storm drain
system located to the north of the project site within the adjacent Cannon Road. Table 1 below
illustrates the pre-developed area to be redeveloped and impervious percentage accordingly.
TABLE 1— SUMMARY OF PRE-DEVELOPED CONDITIONS
Tributary Area, A - Impervious Percentage, FOC MA (Ac) IPM
POC-1 DMA-A 3.71 0%
TOTAL -- 3.71 I 0%
Notes: (1)— Per the 2013 RWaCB permit, existing condition impervious surfaces are not to be accounted for in existing conditions analysis
DEVELOPED CONDITIONS
Storm water runoff from the proposed project site is routed to one (1) POC located at the existing storm
drain location to the north of the project site. Runoff from the developed project site is drained to five
(5) orisite receiving BMPS; four (4) biofiltration LID BMP's and a two (2) underground detention vaults
that are hydraulically linked to act as a single detention facility. Once flows are routed via the proposed
LID BMPs, developed onsite flows are then conveyed to the POC. A small portion of the site is self-
mitigating; this area will bypass the LID BMPs and confluence with flows at the aforementioned POC.
TABLE 2— SUMMARY OF POST-DEVELOPED CONDITIONS
POC DMA
DMA-1A + Payers
Tributary Area, A
(Ac)
0.726
Impervious Percentage, Ip
61.23
BR-1 0.01843 0%
DMA-113 0.325 61.22%
DMA-113 (Payers) 0.089 0%
BR-2 0.00817 0%
DMA-1D 0.341 96.62% POC-1 DMA-iD (Payers) 0.053 0%
BR-3 0.01279 0%
DMA-1C 0.506 92.52%
BR-4 0.01 0%
DMA-1E 1.325 100%
DMA-2A (Self Mitigating) 0.294 6.73%
TOTAL -- 3.71 --
Four (4) LID biofiltration basins and a single underground detention vault are located within the project
site and are responsible for handling hydromodification requirements. In developed conditions, the
basins will have a surface depth of 0.92 feet and a riser spillway structure (see dimensions in Table 4).
Flows will then discharge from the basins via a low flow orifice outlet within the gravel layer. The riser
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BMW Carlsbad HMP Memo
December 13, 2019
structure will act as a spillway such that peak flows can be safely discharged to the receiving
underground detention vault.
Beneath the basins' invert lies the proposed LID biofiltration portion of the drainage facility. This
portion of the basin is comprised of a 3-inch layer of mulch, an 18-inch layer of amended soil (a highly
sandy, organic rich composite with an infiltration capacity of at least 5 inches/hr). Two (2) of the BMP's
(BR-1 and BR-2) are partial-retention systems; these basins will feature 13-inches of gravel while the
remaining two (2) bio-filtration BMPs (BR-3 and BR-4) will be lined and include a 12-inch layer of gravel
for additional detention and to accommodate the French drain system. These systems are to be
located beneath the biofiltration layers to intercept treated storm water and convey these flows to a
single small diameter lower outlet orifice.
Once the runoff has been routed by the outlet structure, flows are then drained to the receiving
underground detention vaults for additional detention. The two (2) spate vaults are to be constructed at
the same elevation and will be linked via the junction box that houses the single outlet structure for the
two (2) facilities. Given that the basin elevations are the same and that both basins are constricted by
the same outlet structure, these facilities are hydraulically linked and act as a single detention facility for
modeling purposes. After these flows have been detained via the detention vault, they will be
discharged to the existing storm drain system located within the adjacen: Cannon Road.
The biofiltration basins were modeled using the biofiltration LID module within SWMM. The
biofiltration module can model the underground gravel storage layer, underdrain with an orifice plate,
amended soil layer, and a surface storage pond up to the elevation of the invert of the spillway. It
should be noted that detailed outlet structure location and elevations will be shown on the construction
plans based on the recommendations of this study.
Water Quality BMP Sizing
It is assumed all storm water quality requirements for the project will De met by the bio-filtration LID
BMPs detailed in the SWQMP and other BMPs included within the site design. However, detailed water
quality requirements are not discussed within this technical memo. For further information in regards
to storm water quality requirements for the project (including sizing and drawdown) please refer to the
site specific Storm Water Quality Management Plan (SWQMP).
Porous Payers
As an integrated LID BMP design practice, several sections of the project sites parking lots will feature
porous pavement/payers. These porous sections will include a 6-inch layer of gravel to be located
beneath the paver to allow for storage of intercepted runoff. There will be no French drain located
beneath the paver section such that once the volume of voids of the gravel has been filled with
stormwater, any excess storm water will continue to surface flow to the receiving storm water quality
bio-filtration basin. The paver base will be unlined to allow for infiltration into the underlying soil.
In some DMA's, cross gutters prevent run-on from adjacent impervious areas into these pervious
sections, such that the only runoff tributary to these LIDs is the direct precipitation that falls upon them.
The DMA's located within the north-eastern portion of the site however do not feature cross gutters,
thus allowing for run-on from the adjacent impervious areas.
3 W.0.7063-02
BMW Carlsbad HMP Memo
December 13, 2019
To represent these differences within the SWMM model, the DMA's that are run-on to the pervious
areas (DMA-1A) are modeled as draining to pervious. Whereas for the porous pavement areas that do
not receive run-on, these areas are modeled as their own individual catchment within SWMM, allowing
for the accurate representation of impervious runoff from adjacent DMA's to bypass these porous
pavement sections and drain directly to the BMP.
Additionally, to represent the 6-inches of gravel storage located beneath the porous pavement French
Drain, the "Dstore-Perv" value for the catchment representing the porous pavement is set to 4.8-inches
(as 12 inches of gravel has only 40% of voids space available for storage, thus 6 X 0.4 = 2.4).
It should be noted that the payers are not treatment control BMPs and as such no draw-down
calculations are required; the 57-year continuous hydrologic SWMM model demonstrates the payers are
able to meet their HMP objective. The bio-filtration BMPs downstream of the payers have been sized
for the full DCV and have not been reduced due to the volumetric interception provided by the paver.
BMP MODELING FOR HMP PURPOSES
Modeling of dual purpose Water Quality/HMP BMPs
Four (4) HMP BMP biofiltration basins and two (2) underground detention vaults are proposed
hydromodification conformance for the project site. Tables 4, 5 and 6 illustrate the dimensions required
for HMP compliance according to the SWMM model that was undertaken for the project.
TABLE 4— SUMMARY OF DEVELOPED DUAL PURPOSE WQ & HMP BMPs
BMP Tributary
Area (Ac)
DIMENSIONS
BMP
i Area(')
(ft)
Gravel
Depth121
(in)
Lower Orif. Depth Riser
D (in)131 Invert (ft)141
Weir Perimeter
Length") (ft)
Total Surface
Depth(61 (ft)
BR-1 0.726 803 13 0.875 1 0.75 8.0 0.92
BR-2 0.414 356 13 0.675 0.75 8.0 0.92
BR-3 0.394 557 12 0.75 0.75 8.0 0.92
BR-4 0.506 435 12 0.75 0.75 8.0 0.92
Notes:' (1): Area of amended soil equal to area of gravel
Includes filter gravel layer, French Drain is set at an elevation of 3-inchesor 4-inches above the base of the facility.
Diameter of orifice in gravel layer with invert at bottom of layer; tied with hydromod min threshold (0.10,).
Depth of ponding beneath riser structure's surface spillway.
Overflow length, the internal perimeter of the riser is 8 ft (2ft x 2ff internal dimensions).
Total surface depth of BMP from top crest elevation to surface invert.
TABLE 5— SUMMARY OF DETENTION VAULTS:
Basin Area (f't2) Depth (ft) Volume (ft')
DETENTION VAULT 1,305 8 10,440
Notes: (1): Volume/area to be distributed between the two (2) individual detention facilities.
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BMW Carlsbad HMP Memo
December 13, 2019
TABLE 6— SUMMARY OF DETENTION VAULT RISER DETAILS:
LowerOrifice Emergency Weir
BASIN Diameter Number of Elev. 11 (ft) Width (ft) Elev (ft) (in) Orifices
DETENTION I1.125 1 0.0 5 7.2083 VAULT I i I
Notes: (1): Invert of basin surface assumed to be elevation O.O.
FLOW DURATION CURVE COMPARISON
The Flow Duration Curve (FDC) for the site was compared at the POC by exporting the hourly runoff time
series results from SWMM to a spreadsheet.
Q2 and Q10 were determined with a partial duration statistical analysis of the runoff time series in an
Excel spreadsheet using the Cunnane plotting position method (which is the preferred plotting
methodology in the HMP Permit). As the SWMM Model includes a statistical analysis based on the
Weibull Plotting Position Method, the Weibull Method was also used within the spreadsheet to ensure
that the results were similar to those obtained by the SWMM Model.
The range between 10% of Q2 and 010 was divided into 100 equal time intervals; the number of hours
that each flow rate was exceeded was counted from the hourly series. Additionally, the intermediate
peaks with a return period "i" were obtained (Q with i=3 to 9). For the purpose of the plot, the values
were presented as percentage of time -exceeded for each flow rate. FDC comparison at the POC is
illustrated in Figure 1 in both normal and logarithmic scale. Attachment V provides a detailed drainage
exhibit for the post-developed condition.
As can be seen in Figure 1, the FDC for the proposed condition with the HMP BMPs is within 110% of the
curve for the existing condition in both peak flows and durations. The additional runoff volume
generated from developing the site will be released to the existing point of discharge at a flow rate
below the 10% Q2 lower threshold for POC-1. Additionally, the project will also not increase peak flow
rates between the Q2 and the 010, as shown in the peak flow tables in Attachment I.
Discussion of the Manning's coefficient (Pervious Areas) for Pre and Post-Development Conditions
Typically the Manning's coefficient is selected as n = 0.10 for pervious areas and n = 0.012 for
impervious areas. Due to the complexity of the model carried out in pre and post-development
conditions, a more accurate value of the Manning's coefficient for pervious areas has been chosen.
Taken into consideration the "Handouts on Supplemental Guidance - Handout #2: Manning's "n" Values
for Overland Flow Using EPA SWMM V.5" by the County of San Diego (Reference [6]) a more accurate
value of n = 0.05 has been selected (see Table 1 of Reference [61 included in Attachment VII). An average
n value between pasture and shrubs and bushes (which is also the value of dense grass) has been
selected per the reference cited, for light rain (<0.8 in/hr) as more than 99% of the rainfall has been
measured with this intensity.
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BMW Carlsbad HMP Memo
December 13, 2019
11WiWJ.i 4'
This study has demonstrated that the proposed HMP BMPs provided for the BMW Carlsbad project site
is sufficient to meet the current HMP criteria if the cross-section areas and volumes recommended
within this technical memorandum, and the respective orifice and outlet structure are incorporated as
specified within the proposed project site.
KEY ASSUMPTIONS
Type B Soils is representative of the existing condition site.
Two (2) separate detention vaults will be constructed at the same elevation and hydraulically
linked, acting as a single detention system.
ATTACHMENTS
Q to Q10 Comparison Tables
FDC Plots (log and natural "x" scale) and Flow Duration Table.
List of the "n" largest Peaks: Pre-Development and Post-Development
Conditions
Elevations vs. Discharge Curves to be used in SWMM
Pre & Post Development Maps, Project plan and section sketches
SWMM Input Data in Input Format (Existing and Proposed Models)
SWMM Screens and Explanation of Significant Variables
Geotechnical Documentation
Summary files from the SWMM Model
REFERENCES
- "Review and Analysis of San Diego County Hydromodification Management Plan (HMP):
Assumptions, Criteria, Methods, & Modeling Tools - Prepared for the Cities of San Marcos,
Oceanside & Vista", May 2012, TRW Engineering.
- "Final Hydromodification Management Plan (HMP) prepared for the County of San Diego",
March 2011, Brown and Caldwell.
- Order 119-20013-001, California Regional Water Quality Control Board San Diego Region
(SDRWQCB).
- "Handbook of Hydrology", David R. Maidment, Editor in Chief. 1992, McGraw Hill.
- "City of Carlsbad BMP Design Manual", February 2016.
- "improving Accuracy in Continuous Hydrologic Modeling: Guidance for Selecting Pervious
Overland Flow Manning's n Values in the San Diego Region", 2016, TRW Engineering.
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I BMW Carlsbad POC 1- Flow Duration Curve
035
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BMW Carlsbad HMI Memo
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BMW Carlsbad POC 1- Flow Duration curve
BMW Carlsbad HMP Memo
December 13, 2019
ATTACHMENT I.
Q to Qjo Comparison Table - POC 1
Return Period Existing Condition (cfs) Mitigated Condition (cfs) Reduction, Exist -
Mitigated (ds)
2-year 1.465 0.811 0.654
3-year 1.820 1.063 0.758
4-year 1.976 1.381 0.595
5-year 2.057 1.590 0.467
6-year 2.227 1.886 0.341
7-year 2.264 1.965 0.299
8-year 2.383 2.060 0.324
9-year 2.490 2.098 0.392
10-year 2.496 2.196 0.300
8 W.0.7063-02
ATTACHMENT II
FLOW DURATION CURVE ANALYSIS
1) Flow duration curve shall not exceed the existing conditions by more than 10%, neither in
peak flow nor duration.
The figures on the following pages illustrate that the flow duration curve in post-development
conditions after the proposed BMP is below the existing flow duration curve. The flow duration
curve table following the curve shows that if the interval 0.10Q2 - Qio is divided in 100 sub-
intervals, then a) the post development divided by pre-development durations are never larger
than 110% (the permit allows up to 110%); and b) there are no more than 10 intervals in the
range 101%-110% which would imply an excess over 10% of the length of the curve (the permit
allows less than 10% of excesses measured as 101-110%).
Consequently, the design passes the hydromodification test.
It is important to note that the flow duration curve can be expressed in the "x" axis as
percentage of time, hours per year, total number of hours, or any other similar time variable. As
those variables only differ by a multiplying constant, their plot in logarithmic scale is going to
look exactly the same, and compliance can be observed regardless of the variable selected.
However, in order to satisfy the City of CarlsbadHMP example, % of time exceeded is the
variable of choice in the flow duration curve. The selection of a logarithmic scale in lieu of the
normal scale is preferred, as differences between the pre-development and post-development
curves can be seen more clearly in the entire range of analysis. Both graphics are presented just
to prove the difference.
In terms of the "y" axis, the peak flow value is the variable of choice. As an additional analysis
performed by REC, not only the range of analysis is clearly depicted (10% of Q2 to Qio) but also
all intermediate flows are shown (0.2, Q3, Q, Q5, Q, Q, Qs and 09) in order to demonstrate
compliance at any range Q - Q+i. It must be pointed out that one of the limitations of both the
SWMM and SDHM models is that the intermediate analysis is not performed (to obtain Q from
= 2 to 10). REC performed the analysis using the Cunnane Plotting position Method (the
preferred method in the HMP permit) from the "n" largest independent peak flows obtained
from the continuous time series.
The largest "n" peak flows are attached in this appendix, as well as the values of Q1 with a
return period "i", from 1=2 to 10. The Q values are also added into the flow-duration plot.
BMW Carlsbad POC 1- Flow Duration Curve
Percentage of time exceeded (%)
— — — — — — — — — — — — — — — — — — —
BMW Carlsbad POC 1- Flow Duration Curve
Flow Duration Curve Data for BMW Carlsbad, City of Carlsbad, CA
Q2 = 1.47 cfs Fraction
Q.10 2.50 cfs
Step= 0.0237 cfs
Count= 499679 hours
57.00 years
Existing Condition Detention Optimized Pass or
Interval Q(cfs) Hours >Q %time Hours>Q %time Post/Pre Fail'
1 0.147 222 4.44E02 239 4.78E-02 108% Pass
2 0.170 206 4.12E-02 213 4.26E-02 103% Pass
3 0.194 186 3.72E-02 191 3.82E-02 103% Pass
4 0.218 179 3.58E-02 168 3.36E-02 94% Pass
5 0.241 175 3.50E-02 143 2.86E-02 82% Pass
6 0.265 170 3.40E-02 118 2.36E-02 69% Pass
7 0.289 169 3.38E02 110 2.20E-02 65% Pass
8 0.313 164 3.28E-02 104 2.08E02 63% Pass
9 0.336 152 3.04E-02 99 1.98E-02 65% Pass
10 0.360 149 2.98E-02 93 1.86E-02 62% Pass
11 0.384 146 2.92E-02 90 1.80E-02 62% Pass
12 0.408 141 2.82E-02 84 1.68E-02 60% Pass
13 0.431 141 2.82E-02 81 1.62E-02 57% Pass
14 0.455 135 2.70E-02 80 1,60E-02 59% Pass
15 0.479 132 2.64E-02 79 1.58E-02 60% Pass
16 0.502 126 2.52E-02 71 1.42E02 56% Pass
17 0.526 121 2.42E-02 66 1.32E-02 55% Pass
18 0.550 116 2.32E-02 64 1.28E02 55% Pass
19 0.574 110 2.20E-02 58 1.16E-02 53% Pass
20 0.597 106 2.12E-02 56 1.12E-02 53% Pass
21 0.621 106 2.12E-02 53 1.06E-02 50% Pass
22 0.645 101 2.02E-02 49 9.81E-03 49% Pass
23 0.669 99 1.98E02 48 9.61E-03 48% Pass
24 0.692 94 1.88E-02 46 9.21E-03 49% Pass
25 0.716 92 1.84E-02 44 8.81E03 48% Pass
26 0.740 89 1.78E-02 43 8.61E-03 48% Pass
27 0.763 86 1.72E-02 41 8.21E-03 48% Pass
28 0.787 83 1.66E-02 37 7.40E-03 45% Pass
29 0.811 81 1.62E-02 36 7.20E-03 44% Pass
30 0.835 79 1.58E-02 32 6.40E-03 41% Pass
31 0.858 74 1.48E-02 32 6.40E-03 43% Pass
32 0.882 72 1.44E-02 29 5.80E-03 40% Pass
33 0.906 71 1.42E-02 28 5.60E-03 39% Pass
34 0.930 58 1.16E-02 28 5.60E-03 48% Pass
35 0.953 58 1.16E02 27 5.40E-03 47% Pass
36 0.977 1 57 1.14E-02 26 5.20E-03 46% Pass
10%
Existing Condition Detention Optimized Pass or
Interval Q (cfs) Hours > Q % time Hours>Q % time Post/Pre Fail?
37 1.001 53 1.06E-02 25 5.00E-03 47% Pass
38 1.025 53 1.06E-02 25 5.00E-03 47% Pass
39 1.048 52 1.04E-02 24 4.80E03 46% Pass
40 1.072 50 1.00E-02 20 4.00E-03 40% Pass
41 1.096 50 1.00E02 20 4OOE-03 40% Pass
42 1.119 50 1.00E-02 19 3.80E-03 38% Pass
43 1.143 48 9.61E-03 19 3.80E-03 40% Pass
44 1,167 47 9.41E-03 18 3.60E-03 38% Pass
45 1.191 47 9.41E03 18 3.60E03 38% Pass
46 1.214 47 9.41E03 18 3.60E-03 38% Pass
47 1.238 43 8.61E-03 18 3.60E-03 42% Pass
48 1 1.262 43 8.61E-03 18 3.60E-03 42% Pass
49 1.286 41 8.21E-03 18 3.60E-03 44% Pass
50 1.309 37 7.40E-03 17 3.40E-03 46% Pass
51 1.333 35 7.00E-03 17 3.40E-03 49% Pass
52 1.357 35 7.00E-03 16 3.20E-03 46% Pass
53 1.380 35 7.00E-03 16 3.20E-03 46% Pass
54 1.404 33 6.60E-03 15 3.00E-03 45% Pass
55 1.428 33 6.60E-03 15 3.00E-03 45% Pass
56 1.452 33 6.60E-03 15 3.00E-03 45% Pass
57 1.475 32 6.40E-03 15 3.00E-03 47% Pass
58 1.499 32 6.40E03 14 2.80E-03 44% Pass
59 1.523 31 6.20E-03 14 2.80E-03 45% Pass
60 1.547 31 6.20E-03 14 2.80E-03 45% Pass
61 1.570 30 6.00E-03 13 2.60E-03 43% Pass
62 1.594 29 5.80E-03 12 2.40E-03 41% Pass
63 1.618 27 5.40E-03 11 2.20E-03 41% Pass
64 1.641 26 5.20E-03 11 2.20E-03 42% Pass
65 1.665 25 5.00E-03 11 2.20E-03 44% Pass
66 1.689 23 4.60E-03 11 2.20E-03 48% Pass
67 1.713 23 4.60E-03 11 2.20E-03 48% Pass
68 1.736 23 4.60E-03 11 2.20E03 48% Pass
69 1.760 23 4.60E-03 11 2.20E-03 48% Pass
70 1.784 23 4.60E-03 11 2.20E-03 48% Pass
71 1.808 23 4.60E-03 11 2.20E-03 48% Pass
72 1.831 22 4.40E-03 11 2.20E-03 50% Pass
73 1.855 21 4.20E-03 11 2.20E-03 52% Pass
74 1.879 19 3.80E-03 11 2.20E-03 58% Pass
75 1.903 18 3.60E-03 10 2.00E-03 56% Pass
76 1.926 18 3.60E-03 9 1.80E-03 50% Pass
77 1.950 18 3.60E-03 9 1.80E-03 50% Pass
78 1.974 17 3.40E-03 9 1.80E-03 53% Pass
79 1.997 17 3.40E-03 9 1.80E-03 53% Pass
80 2.021 16 3.20E03 9 1.80E-03 56% Pass
81 2.045 14 2.80E-03 9 1.80E-03 64% Pass
Existing Condition Detention Optimized Pass or
interval Q (cfs) Hours > Q % time Hours>Q % time Post/Pre Fail?
82 2.069 12 2.40E-03 7 1.40E-03 58% Pass
83 2.092 12 2.40E-03 7 1.40E-03 58% Pass
84 2.116 12 2.40E-03 7 1.40E-03 58% Pass
85 2.140 10 2.00E-03 7 1.40E-03 70% Pass
86 2.164 10 2.00E-03 7 1,40E03 70% Pass
87 2.187 10 2.00E-03 7 1.40E-03 70% Pass
88 2.211 10 2.00E-03 7 1.40E-03 70% Pass
89 2.235 9 1.80E-03 6 1.20E-03 67% Pass
90 2.258 8 1.60E-03 5 1.00E-03 63% Pass
91 2.282 8 1.60E-03 5 1.00E-03 63% Pass
92 2.306 8 1.60E-03 5 1.00E-03 63% Pass
93 2.330 7 1.40E-03 5 1.00E-03 71% Pass
94 2.353 7 1.40E-03 5 1.00E-03 71% Pass
95 2.377 7 1.40E-03 5 1.00E-03 71% Pass
96 2.401 7 1.40E03 5 1.00E-03 71% Pass
97 2.425 7 1.40E-03 4 8.01E-04 57% Pass
98 2.448 7 1.40E-03 4 8.01E-04 57% Pass
99 2.472 7 1.40E-03 4 8.01E-04 57% Pass
100 2.496 6 1.20E-03 4 8.01E-04 67% Pass
Peak Flows calculated with Cunnane Plotting Position
Return Period
(years) Pre-dev, Q )cfs)
Post 0ev. Q
(cfs)
Redut on
(cfs)
10 2.496 2.196 0.300
9 2.490 2.098 0.392
8 2.383 2.060 0.324
7 2.264 1.965 0.299
6 2.227 1.886 0.341
5 2.057 1.590 0.467
4 1.976 1.381 0.595
3 1.820 1.063 0.758
2 1.465 0.811 0.654
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ATTACHMENT Ill
List of the "n" Largest Peaks: Pre & Post-Developed Conditions
Basic Probabilistic Equation:
R = 1/P R: Return period (years).
P: Probability of a flow to be equaled or exceeded any given year (dimensionless).
Cunnane Equation: Weibull Equation:
p=i_o,4 n+O.2 n+1
i: Position of the peak whose probability is desired (sorted from large to small)
n: number of years analyzed.
Explanation of Variables for the Tables in this Attachment
Peak: Refers to the peak flow at the date given, taken from the continuous simulation hourly
results of then year analyzed.
Posit: If all peaks are sorted from large to small, the position of the peak in a sorting analysis is
included under the variable Posit.
Date: Date of the occurrence of the peak at the outlet from the continuous simulation
Note: all peaks are not annual maxima; instead they are defined as event maxima, with a
threshold to separate peaks of at least 12 hours. In other words, any peak P in a time series is
defined as a value where dP/dt = 0, and the peak is the largest value in 25 hours (12 hours
before, the hour of occurrence and 12 hours after the occurrence, so it is in essence a daily
peak).
List of Peak events and Determination of Q2 and Q10 (Pre-Development)
BMW Carlsbad - POC 1
(Year)
Cunnane
(cfs)
Welbull
(cfs) Peaks (cfs)
Date Posit
Period of Return
(Years)
10 2.50 2.59 Weibull Cunnane
9 2.49 2.49 0.908 1/15/1978 57 1.02 1.01
8 2.38 2.44 0.923 9/18/1963 56 1.04 1.03
7 2.26 2.29 0.923 1/11/2005 55 1.05 1.05
6 2.23 2.23 0.926 3/15/1986 54 1.07 1.07
S 2.06 2.07 0.926 12/24/1988 53 1.09 1.09
4 1.98 1.99 0.927 2/19/1958 52 1.12 1.11
3 1.82 1.82 0.929 1/6/1979 51 1.14 1.13
2 1.47 1 1.47 0.986 8/17/1977 50 1.16 1.15
Note:
Cunnane is the preferred
method by the HMP permit.
0.992 2/22/1998 49 1.18 1.18
0.992 2/12/2003 48 1.21 1.20
0.994 11/8/2002 47 1.23 1.23
1.039 12/31/2004 46 .26 - 1.25
1.053 2/4/1994 45 1.29 1.28
1.069 3/1/1991 44 1.32 1.31
1.123 11/11/1985 43 1.35 1.34
1.137 4/27/1960 42 1.38 1.38
1.157 2/14/1998 41 1,41 1.41
1.226 1/18/1993 40 1.45 1.44
1.237 12/2/1961 39 1.49 1.48
1.277 2/12/1992 38 1.53 1.52
1.292 2/15/1986 37 1.57 1.56
1.296 3/2/1980 36 1.61 1.61
1.304 1/16/1978 35 1.66 1.65
1.304 1/29/1980 34 1.71 1.70
1.32 3/11/1995 33 .76 - 1.75
1.325 1/6/2008 32 .81 - 1.81
1.394 12/30/1991 31 1.87 1.87
1.394 2/17/1998 30 1.93 1.93
1.465 1/27/2008 29 2.00 2.00
1.512 2/23/1998 28 2.07 2.07
1.59 10/20/2004 27 2.15 2.15
1.595 2/16/1980 26 2.23 2.23
1.611 2/10/1978 25 2.32 2.33
1.627 11/22/1965 24 2.42 2.42
1.664 2/27/1983 23 2.52 2.53
1.667 1/29/1983 22 2.64 2.65
1.667 2/3/1998 21 2.76 2.78
1.808 3/17/1982 20 2.90 2.92
1.832 1/16/1952 19 3.05 3.08
1.856 11/15/1952 18 3.22 3.25
1.864 12/19/1970 17 3.41 3.45
1.879 10/27/2004 16 3.63 3.67
1.958 4/1/1958 15 3.87 3.92
2.021 1/14/1993 14 4.14 4.21
2.034 3/1/1978 13 4.46 4.54
2.046 2/20/1980 12 4.83 4.93
2.12 2/18/2005 11 5.27 5.40
2.227 10/29/2000 10 5.80 5.96
2.235 2/25/1969 9 6.44 6.65
2.309 2/4/1958 8 7.25 7.53
2.488 9/23/1986 7 8.29 8,67
2.497 2/25/2003 6 9.67 10.21
3.025 1/4/1995 5 11.60 12.43
3.175 1/15/1979 4 14.50 15.89
3.525 1/4/1978 3 19.33 22.00
3.541 10/1/1983 2 29.00 35.75
3.911 4/14/2003 1 58.00 95.33
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List of Peak events and Determination of Q2 and Q10 (Post-Development)
BMW Carlsbad - POC I
T
(Year)
Cunnane
(cfs)
Weibull
(cfs) Peaks (cfs)
Date Posit
Period of Return
(Years)
10 2.20 2.22 Weibull Cunnane
9 2.10 2.14 0.233 1/14/1993 57 1.02 1.01
8 2.06 2.06 0.237 12/17/1987 56 1.04 1.03
7 1.97 2.01 1 0.237 10/29/2000 55 1.05 1.05
6 1.89 1.89 0.238 3/2/1983 54 1.07 1.07
5 139 1.59 0.238 10/12/1987 53 1.09 1.09
4 1.38 1.41 0.239 2/14/1954 52 1.12 1.11
3 1.06 1.07 0.242 1/6/1977 51 1.14 1.13
2 - 0.81 0.81 0.243 12/19/1967 50 1.16 1.15
Note:
Cunnane is the preferred
method by the HMP permit.
0.243 2/18/2005 49 1.18 1.18
0.271 9/23/1986 48 1.21 1.20
0.359 4/1/1958 47 1.23 1.23
0.372 10/20/2004 46 1.26 1.25
0.375 1/15/1993 45 1.29 - 1.28
0.376 1/11/2005 44 1.32 - 1.31
0.394 12/29/2004 43 .35 - 1,34
0.426 1/27/1956 42 138 1.38
0.482 12/25/1983 41 1.41 1.41
0.483 1/18/1952 40 1.45 1.44
0.502 1/16/1952 39 1.49 1.48
0.503 2/18/1980 38 1.53 1.52
0.514 1/11/1980 37 1.57 1.56
0.562 1/18/1993 36 1.61 1.61
0.58 10/27/2004 35 1.66 1.65
0.617 1/22/1967 34 1.71 1.70
0.624 3/3/1983 33 1.76 1.75
0.637 1/25/1969 32 1.81 1.81
0.751 3/11/1995 31 1.87 1.87
0.759 11/22/1996 30 1.93 1.93
0.811 12/5/1966 29 2.00 2.00
0.814 1/20/1962 28 2.07 2.07
0.824 3/5/1995 27 2.15 2.15
0.866 11/30/2007 26 2.23 2.23
0.905 1/16/1993 25 2.32 2.33
0.947 1/9/2005 24 2.42 2.42
0.998 1/13/1997 23 2.52 2.53
1.033 2/23/2005 22 2.64 2.65
1.05 3/8/1968 21 2.76 2.78
1.054 1 1/15/1978 20 2.90 2.92
1.071 1/6/1979 19 3.05 3.08
1.1 2/15/1986 18 3.22 3.25
1.149 2/22/2008 17 3.41 3.45
1.299 3/1/1991 16 3.63 3.67
1.336 1/16/1978 15 3.87 3.92
1.494 2/23/1998 14 4.14 4.21
1.56 1/29/1980 13 4.46 4.54
1.588 11/22/1965 12 4.83 4.93
1.6 3/17/1982 11 5.27 5.40
1.885 2/20/1980 10 5.80 5.96
1.905 3/1/1978 9 6.44 6.65
2.056 2/25/1969 8 7.25 7.53
2.065 2/4/1958 7 8.29 8.67
2.217 2/25/2003 6 9.67 10.21
2.237 1/4/1978 5 11.60 12.43
2.606 10/1/1983 4 14.50 15.89
2.766 1/15/1979 3 19.33 22.00
3.323 1/4/1995 2 29.00 35.75
3.7 4/14/2003 1 58.00 95,33
ATTACHMENT IV
AREA VS ELEVATION
The storage provided beneath the first surface outlet by the LID BMP is entered into the LID
Module within SWMM - please refer to Attachment VII for further information. The surface bio-
filtration BMPs are bordered by vertical walls, as such the area is constant with depth.
Similarly, the underground detention vault has a constant area as the depth increases due to it
being a walled structure.
DISCHARGE VS ELEVATION
The orifices have been selected to maximize their size while still restricting flows to conform
with the required 10% of the Q2 event flow as mandated in the Final Hydromodification
Management Plan by Brown & Caldwell, dated March 2011. While REC acknowledges that
these orifices are small, to increase the size of these outlets would impact the basin's ability to
restrict flows beneath the HMP thresholds, thus preventing the BMP from conformance with
HMP requirements.
In order to further reduce the risk of blockage of the orifices, regular maintenance of the riser
and orifices must be performed to ensure potential blockages are minimized. A detail of the
orifice and riser structure is provided in Attachment V of this memorandum.
The LID low flow orifice discharge relationship is addressed within the LID Module within
SWMM - please refer to Attachment VII for further information.
I
DISCHARGE EQUATIONS
1) Weir:
c w_— r'W'L t1 i u3/2 'e 1
2) Slot:
As an orifice: Q5 = B c9 J2g (H
-
As a weir: Q =CW.B'. H 312
For H > h5 slot works as weir until orifice equation provides a smaller discharge. The elevation such that
equation (2.a)
= equation (2b) is the elevation at which the behavior changes from weir to orifice.
3) Vertical Orifices
I As an orifice: Q0 = 0.25 rW2 ,j29 (H
-
(3.a)
I As a weir: Critical depth and geometric family of circular sector must be solved to determined Q as a function of
H:
Q A A D2 I —=—; H= y+ ; cr 2/ycr(Dycr); Acr g cr cr
I Ycr = [1 - sin(0.5 . ac,)] (3.b.1, 3.b.2, 3.b.3, 3.b.4 and
There is a value of H (approximately H = 110% D) from which orifices no longer work as weirs as critical depth is
I not possible at the entrance of the orifice. This value of H is obtained equaling the discharge using critical
equations and equations (3.b).
A mathematical model is prepared with the previous equations depending on the type o discharge.
The following are the variables used above:
= Discharge of weir, slot or orifice (cfs)
I
C, c8 : Coefficients of discharge of weir (typically 3.1) and orifice (0.61 to 0.62)
L, B, D, h: Length of weir, width of slot, diameter of orifice and height of slot, respectively; (ft)
H: Level of water in the pond over the invert of slot, weir or orifice (ft)
Acr, Tcr, Ycr, acr: Critical variables for circular sector: area (sq-ft), top width (ft), critical depth (ft), and angle to the center,
I respectively.
Outlet structure for Discharge of Underground Vault
Discharge vs Elevation Table
Low orifice: 1.125 1, Lower slot
Number: 1 Invert: 0.00 ft
Cg-low: 0.61 B 0.00 ft
Middle orifice: I " h 0.000 ft
number of orif: 0 Upper slot
Cg-middle: 0.62 Invert: 0.000 ft
invert elev: 0.25 ft B: 0.00 ft
h 0167 ft
Emergency Weir
Invert: 7.208 ft
B: 5 f
h
(ft)
HID-low
-
HID-mid
-
Qiow-orif
(cfs)
Ojow-weir
(cfsl
Qtot-low
(cfs)
Qmid-orlf
(cfs)
Qmld-weir
(cfs)
Qtot-med
(cfs)
Qslot-low
(cfs)
Qslot-upp
(cfs)
Qemer
(cfs)
Qtot
(cfs)
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
0.250 2.667 0.000 0.015 0.019 0.015 0.000 0.000 0.000 0.000 0.000 0.000 0.015
0.500 5.333 3.000 0.023 0.202 0.023 0.000 0.000 0.000 0.000 0.000 0.000 0.023
0.750 8.000 6.000 1 0.028 0.283 1 0.028 0.000 0.000 1 0.000 0.000 0.000 1 0.000 0.028
1.000 10.667 9.000 0.033 0.330 0.033 0.000 0.000 0.000 0.000 0.000 0.000 0.033
1.250 13.333 12.000 0,037 0.371 0.037 0.000 0.000 0.000 0.000 0.000 0.000 0.037
1.500 16.000 15.000 0.041 0.407 0.041 0.000 0.000 0.000 0.000 0.000 0.000 0.041
1.750 18.667 18.000 0.044 0.441 0.044 0.000 0.000 0.000 0.000 0.000 0.000 0.044
2.000 21.333 21.000 0.047 0.472 0.047 0.000 0.000 0.000 0.000 0.000 0.000 0.047
2.250 24.000 24.000 0.050 0.502 0.050 0.000 0.000 1 0.000 0.000 0.000 1 0.000 0.050
2.500 26.667 27.000 0.053 0.529 0.053 0.000 0.000 0.000 0.000 0.000 0.000 0.053
2.750 29.333 30.000 0.056 0.556 0.056 0.000 0.000 0.000 0.000 0.000 0.000 0.056
3.000 32.000 33.000 0.058 0.581 0.058 0.000 0.000 0.000 0.000 0.000 0.000 0.058
3.250 34.667 36.000 0.060 0.605 0.060 0.000 0.000 0.000 0.000 0.000 0.000 0.060
3.500 37.333 39.000 0.063 0.628 0,063 0.000 0.000 0.000 0.000 0.000 0.000 0.063
3.750 40.000 42.000 0.065 0.650 0.065 0.000 0.000 1 0.000 0.000 0.000 0.000 0.065
4.000 42.667 45.000 0.067 0.672 0.067 0.000 0.000 0.000 0.000 0.000 0.000 0.067
4.250 45.333 48.000 0.069 0.693 0.069 0.000 0.000 0.000 0.000 0.000 0.000 0.069
4.500 48.000 51.000 0.071 0.713 0.071 0.000 0.000 0.000 0.000 0.000 0.000 0.071
4.750 50.667 54.000 0.073 0.733 0.073 0.000 0.000 OMOO 0.000 0.000 0.000 0.073
5.000 53.333 57.000 0.075 0.752 0.075 0.000 0.000 0.000 0.000 0.000 0.000 0.075
5.250 56.000 60.000 1 0.077 0.771 0.077 0.000 0.000 1 0.000 0.000 0.000 0.000 0.077
5.500 58.667 63.000 0.079 0.789 1 0.079 0.000 0.000 0.000 0.000 0.000 0.000 0.079
5.750 61.333 66.000 0.081 0.807 0.081 0.000 0.000 0.000 0.000 0.000 0.000 0.081
6.000 64.000 69.000 0.082 0.824 0.082 0.000 0.000 0.000 0.000 0.000 0.000 0.082
6.250 66.667 72.000 0.084 0.842 0.084 0.000 0.000 0.000 0.000 0.000 1 0.000 0.084
6.500 69.333 75.000 0.086 0.858 0.086 0.000 0.000 0.000 0.000 0.000 0.000 0.086
6.750 72.000 78.000 0.087 0.875 0.087 0.000 0.000 1 0.000 0.000 0.000 0.000 0.087
7.000 74.667 81.000 0.089 0.891 1 0.089 0.000 0.000 0.000 0.000 0.000 0.000 0.089
7.208 76.885 83.496 0.090 0.904 0.090 0.000 0.000 0.000 0.000 0.000 0.000 0.090
7.500 80.000 87.000 0.092 0.923 0.092 0.000 0.000 0.000 0.000 0.000 2.442 2.534
7.750 82.667 90.000 0.094 0.938 0.094 0.000 0.000 0.000 0.000 0.000 6.180 6.273
8.000 85.333 93.000 0.095 0.953 0.095 0.000 0.000 0.000 0.000 0.000 1 10.919 11.014
8
8 4
4 * 8
88
"8
8,8 "44 * 'c g -
AW
Ta
As
fm
88
AV
'-
-"8
4 88
-8 8 -'8
Lot :
'8
,, U
TV 8.
'88
Nos
;84l 8'88
5 48 -1-815 .:: 05 :..:1 - 8,,:88 -:8
BROW\ AND
(..A 1 1) W E 1, I
- - - - - - - - - - - - - - - - - - -
ATTACHMENT V
Pre & Post-Developed Maps, Project Plan and Detention
Section Sketches
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LEGEND:
'. C54114510414'533v11s35,:
005030.A18OE ISWFP.S —541— 90410415<1) S .33,3418544509010.1)
ILIED 1343505
505510 051-550505
1).i1)M'55 K..)- P410-c) 415X544405143
880)545<90)3055
5053411 8418
<
GEOTECHNICAL INFO.
41"•05454 0413' 5434" 48
3551.481405 5 83.4103
5414,3.54354515550 5)544.90480141W
.I,'83"44 i413ojuMiW51h0i >541
CCSYA ANALYSIS:
/4_c .41:0414135<345541>543090).': 4010''8 3) 14. 5,30, 4143,9041
BMP DETAILS:
5041 50, 13355 51)Ao41 :34031541)430504 3.04 00501)3'
DMA SUMMARY
00109, 8:
333
54n
041
334*30*38051 3303804 0513*1543304 430(81
4 3* 5354
35 30','94539 44303 9,8334 01 8
143
#4L30441033019013034W/AFT4N1004 '1 90(41
33 3083834',',, " 84031 8183,
02 1l143' 0* 1 OS'S! 1,21' 0829
II 54o'r. 34,3', 3,340' 0834
34 11.141*30* .33,3,! 3,1305 34743,
330',147,540o9,, 3,304 3038
30,1, ' 85,21 M*.1C+ POOIOLIUOO** 00149 4909,331
41 33,,'JP**,,*! 2.031 0135
31 134330,3,, 58., lOSS 3834
0 ,3"hl 31)8
140.1043 $1063313431034 401331490<31
34 83,4*303,33,3:0 13,53s 0540
43*1941 . 54, 33'' 833)3.
13 3, 1)17453,0143, I'S 0315$
3' 319"011, 0,430 .....03 0.33
140.16*0310103433,9,1303101 3143053 '3 904*4
(144.7,44 1330014333541044 493A,P01I1
1/54 :31 40 -38%! , 3',33
#0< #0 30300 143.1/13 3354
20 0 20 40
GRAPHIC SCALE
SCALE' 7"= 20'
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1 I4or:Ioc.IIX,wlrnpoAT: .,"20i1IrTop 'hA'. .4 '001141--lI 113 II. 14.1) -1(41
7044.11*10)114 II 1' 7 4-70 $14111. 13140111 131 114,401 20±111'.
Galv
,-OW,CA11'0(1A054,0 011*11-
.
70004,,?' ,ll TOo
111300.1
-01015-ok,' 114€'.
:.
114.l4-40111,115
11 rV4*.o4L,
"t,-,C4'11 4E) 111111171,041)0101200104
4-4-01131011-701114
If 1
f -C <'*1614' I
6201 II '11171 $11101 I0'*4.1,11401' XIII 4.7<51*11 13)11347*7*
1170,,- 11,4,1*40 401112.111101'.U"I
BMP-1 & BMP-2; BIOFILTRATION BASIN
W/ PARTIAL RETENTION
021.011.000001*3.70
0' 41)11171±01
- - * 211 1)116144-CO
r' 4'
111754.
I IT2X.11,16
6
'1III'
'Fl/I *412' 44 71111.'
:' tZ4-'4 L
-- .0 0,1
.1111711.
1. )i4-Xii11.310110V3'/Aii*O 111.1*11111' 11; *102011
1. T4I'001/E4-OIELEIEO.2001$4iI.OIS00921400111111111110001 1AI1iI1*V00*lh117701.414i 1iE>111il>E007114.ECV
l'YPIOAo 041112, 0020" SF0111120
BMP-3 & BMP-4: BIOFILTRATION BASIN
W/ IMPERMEABLE LINER
LZ
14 /
.24-0,01 4-)' 441.1
UNDERDRAIN
CLEAJOU1 (CO) DETAIL
BASIN BMP RISER
OUTLET DETAIL
1 I íJ
I U w a
w
I-
U)
>-
C/) z
N o
z U-1
I- w a
RISER INFORMATION STUB INFORMATION I STUB INFORMATION
BMP-6A:
WEST OF PROPOSED BUILDING
-- >
NORTH 00 PROPOSED BUILDING
BMP-6B:
RISER INFORMATION
It I
AlP ,/ k.TC. ,,,/ APP ElLA 04
LAC04AA'.
2004
1141. 1110418$ NEOIIZIIVISO 0117*20615 74*. ArVAGNE,
41 PACES 611000±60 TIlE 10100*460;
P015 STORAGE 41 CF
M4W PIPE GAGE
DIAMETER *IC
FINIS*IALT2
CORRUGATION 501
TYPE -so ID
ASSEMBLY
PIPEwALL STORAGE 6,681 Cl
LOAOlNG; 1120 PiPE 1071. 07.50*
61 Er 100NZ*A6$APVL AMP AAAAtlA04wii.64041140 47ltDOfl)C0A.PJC &IJ70SIIPACE 8H*]_l.PE70tWAL74jOt,'rfl 04lAtwrrr 6700.01111 070 V674%ORIE, lilt Snip 810700'71'll VVII.1 P'0111C111707. '11,411110704-, 41100 411 0 111 1$ 11.44, 0*4 14. *4 II VA 114' 1€
10170 A464tERCPII700L'Ao*OVWOcIONAEAEOI.
.&, P0*6416501ST *1CTiI7*$.V10000*110r,*RE;01flVt4Llt7IOVc*411*spW4ACS , '5 ,. 0* '*0'
070*0000 0,400 VA 174.4 0$A.4041*V410 '
4-48*108*4*0.0641141 11$ 051.A,L0 ,WC11*IO4A*14I1*Ebi 41±ERU4*1111$t$1$ '..
ro€ : ''- "0'
101.? 001011*34* 18OCT11 *EP*70-0CLfl.3Sw4j5E.AOtrO7*Q467*
€70 202000 0104.16*106 ATTACIlO 41PAGE$441100140 V EIE$.i.OWISIO:
PIPE STORAGE 4714 MAIIIUNEPIPEGAGE 16
DIAMETER 967 PINISII*ALT2
COOCRUGATIOII si
PIPE 81011404 4.776 CE
LOAO1NG: 4120
PIPE NV. 4- 87.0071
ASSEMBLY 7.4*17*
.1AJ(K€POSCP&L Vt ?G6AtOfl,fAPt6 Sltlt,M<3 COCVCCW6L 61701104 117 t7E)1AI*A27000 WA OACSSIALLSE F'JACPE.0ON04Y.04OZ49PH 11171$ 70161116117*7610111702 1116 67001.qtl1uC0'UAC.lEpO11700*rEC * *1 44 11 SI 11*0*. 4$.4 '644.. CCIII P
Vt* 4-LAO. 7067070047011417060*1 .04.114.1.
.040 liv *r5S*4$107447111701414J.7 000C000410100610201101610001151644-04'flO 77* 4*41160 *4*1 6*41
-'
46411'*$l,t*OIIESSAASLIAOIIIH *0807006±$liLS'000IO2*lA11A1i 'HUiSIEIIO,*l**I.
*44170*1 480.1 44*000*0 14460*1 611
I051000A114A*A*0 15*0 Th0*144$I010MAA00000*7040844L01 *004115*440
"'T20iI04r 720r'"
-n
-w-At 41T.CA0C11YVIIt'.*4*1A*0.501I10'1 I00061ACT ''wuor' 71o'r,, .ACC*0$L$*04I1* OIALLSTAVIAGIEOWI
L CNTECH 960 UNDERGROUND DETENTION SYSTEM -617515010 IT ,]0A0 . CNTECH 960 UNDERGROUND DETENTION SYSTEM -617515-020 _______________________ INGRR70EDSOUJTION8 UC 1P5E20IO1OR04T9MS
[PROPOSAL]
BMW CARLSBAD o
SITE DESIGNATION BMP 6A
CARLSBAD,CA
TX
S3N70MD sunop .61
'6 1
BMW CARLSBAD
CARLSBAD,CA
SITE DESIGNATION BMP 69 P1 4 '5*0*4*01.71*
C/)
-J
w a z
J)
NOTES:
I. EMP-SA AND BMP.SB TC)ACT AS ONE DETENTION
SYSTEM THAT IS HYDRAULICALY CONNECTED VP, 12'
HOPE PIPE AND SET AT ONE ELEVATION.
2. BMP-11 SHALL HAVE A MINIMUM TOTAL STORAGE
VOLUME OF 10,440 CU-FT.
/ THAN 0111 011*42
I-' P201 PEE EMPEXXED
4-"1p,4 0100080T 1040
'2X1'D,$ C0EI0 fu4
FLOW CONTROL ORIFICE PLATE
A
47 4 T1-1513 METAL PLATE
'4' I
24. IIIE _•
L
12' 014, 10-PC Ni 111 RUM
OIITFISTUN VAuLT
OUTLET STRUCTURE & WEIR DETAIL
PREPARED FOR; PREPARED BY:
AUTOIOATICJN ING.
200 SW 1STSTITEE7, I4THFLOO11
FORTLAUDILIIDALC. PL 33301 •:--. Commercial
CONTACT: CLIFF POWELL ;' Development
TEL: I904 760-206140 C Resources
Tols,'• 10*35, T$17*I100'S T*S$tY.
11.661
A
11 MET,4LTL30EDIi'...
4
-LJILETTI000FA
F / 5000004149000
I 0004011010
SIP0ICILJ$16
SHEET 02 OF 02
SWQMPATTAcIIMENT 2A:
HMP EXHIBIT
BMW OF CARLSBAD
1060 AUTO CENTER COURT
CARLSBAD, CA 92008
ATTACHMENT VI
SWMM Input Data in Input Format (Existing & Proposed Models)
PREDEV
[OPTIONS';
FLOW U. ITS CFS
INF11.TRAT1ON GREEN AMPT
FLOW ROUTING KINWAVE
START DATE 10/01/1951
START TIME 00:00:80
REPORT START DATE 10/01/1951
REPORT—START—TIME 00:00:00
END DATE 09/30/2009
END TINE 23:00:80
SWEEP START 01/01
SWEEP END 12/31
DRY DAYS 0
REPORT STEP 01:00:00
WET STEP 00:15:00
DRY STEP 04:00:00
ROUTING STEP 0:01:00
ALLOW PONDING NO
INERTIAL DAMPING PARTIAL
VARIABLE STEP 0.75
LENGTHENING STEP 0
WIN SURFAREA 0
NORMAL FLOW LIMITED BOTH
SKIP STEADY STATE NO
FORCE MAIN EQUATION H-N
LINK OFFSETS DEPTH
WIN SLOPE 0
LEVAPORATION
;Type Parameters
MONTHLY 0.03 0.05 0.08 0.1.1 0.13 0.15 0.15 0.1.3 0.11 0.08 0.04 0.02
DRY ONLY NO
[RAINGAGESI
Rain Time Snow Data
Name Type Intrv1 Catch Source
Oceanside INTENSITY 1:00 1.0 TIMESERIES Oceanside
I SUECATCHMEN IS
Total PCnt. Pent. Curb Snow
;Name Raingage Outlet Area Lmpery Width Slope Length Pack
DMA-A Oceanside POC-1 3.71 0 979 3 - 0
[SUBAREAS]
Subcatchment N-Impery N-.Pery S-Imoery S-Pery PctZe.ro Rote.To PctRouted
DMA-A 0.012 0.05 0.05 0.1 25 OUTLET
[INFILTRATION]
;Suhcatchment. Suction HydCcn INDmax
DMA-A 3 0.15 0.31
[OUTFALLS I
Invert; Outfall Stage/Table Tide
;;Name Elev. Type Time Series Gate
P00-1 0 FREE NO
[TIMESERIES]
Name Date Time Value
Oceanside FILE "OsideRain.prn"
[REPORT]
INPUT. NO
PREDEV
CONTROLS NO
SUBCATCHNENTS ALL
NODES ALL
LINKS ALL
1TAGS
(MAP)
DIMENSIONS -8510.915 4908.181 -8482.307 8731.478
Units None
(COORDINATES
Node X-coord Y-Coord
P00-i -8483.907 5081.967
(VERTICES)
Link X-Coora Y-Coord
[Polygons)
Subcatchrnent X-Coord Y-Coord
DMA-A -8483.607 6622.951
[SYMBOLS]
Gage X-Coord Y-Coord
Oceanside -8489.868 7908.829
POST DEV
[TITLE
[OPTIONS]
FLOW UNITS CFS
INFILTRATION GREEN AMPT
FLOW ROUTING KINWAVE
START DATE 10/01/1951
START TIME 00:00:00
REPORT START DATE 10/01/1951
REPORT START TIME 00:00:00
END DATE 09/30/2008
END TINE 23:00:00
SWEEP START 01/01
SWEEP END 12/31
DRY DAYS 0
REPORT STEP 01:00:00
WET STEP 00:15:00
DRY STEP 04:00:00
ROUTING STEP 0:01:00
ALLOW PONDING NO
INERTIAL DAMPING PARTIAL
VARIABLE STEP 0.75
LENGTHENING STEP 0
WIN SURFAREA 0
NORMAL FLOW LIMITED BOTH
SKIP STEADY-STATE NO
FORCE MAIN EQUATION H-N
LINK OFFSETS DEPTH
WIN SLOPE 0
[EVAPORATION)
Type Parameters
MONTHLY 0.03 0.03 0.08 0.11 0.13 0.15 0.15 0.13 0.11 0.08 0.04 0.02
DRY ONLY NO
[RAINGAGES.J
Rain Time Snow Data
Type Intrv1 Catch Source
Oceanside INTENSITY 1:00 1.0 TIMESERIES Oceanside
[SUBCATCHMENTS]
Total Pont. Pont. Curb Snow
;;Narne Raingage Outlet Area Irnpery Width Slope Length Pack
DMA-ID Oceanside DR-3 0.341 96.62 52 1 0
DMA-2A(SN) Oceanside POC-1 0.294 6.73 128 1 0
BR-3 Oceanside Vault 0.01279 0 10 0 0
DMA-1B Oceanside BR-2 0.325 61.22 71 1 0
DMA-IC Oceanside BR-4 0,506 92.52 78 1 0
BR-2 Oceanside Vault 0.00817 0 10 C. 0
BR-1 Oceanside Vault 0.01843 0 10 0 0
BR-4 Oceanside Vault 0.009986 0 10 0 0
DMA-lBPavere) Oceanside BR-2 0.089 0 77 1 0
DMA-iD(Favers) Oceanside BR-3 0.053 0 46 1 0
DMA -lB Oceanside VAULT 1.325 100 124 1 0
DMA-IA-fPavers Oceanside BR-1 0.726 61.23 86 1 0
(SUBAREAS)
Subcatchmert N-Impery N-Pery S-Iapery S-Pery Pctlero RouteTo PctRouted
DMA-ID 0.012 0.05 0.05 0.1 25 OUTLET
DMA-2A(SM) 0.012 0.05 0.05 0.1 25 OUTLET
BR-3 0.012 0.05 0.05 0.1 25 OUTLET
DMA-lB 0.012 0.05 0.05 0.1 25 OUTLET
DMA-IC 0.012 0.05 0.05 0.1 25 OUTLET
BR-2 0.012 0.05 0.05 0.1 25 OUTLET
BR-1 0.012 0.05 0.05 0.1 25 OUTLET
BR-4 0.012 0.05 0.05 0.1 25 OUTLET
DNA-IBPavers) 0.012 0.05 0.05 2.4 25 PERVIOUS 100
POST_DEV
DMA-1D(Pavers) 0.012 0.05 0.05 2.4 25 .PERVIOUS 100
DMA-11- 0.012 0.05 0,05 0.1 25 OUTLET
DMA-iA+Pavers 0.012 0.05 0.05 2.4 25 PERVIOUS 100
[INFILTRATION]
;;Subcatchment Suction HydCon Ir.lornax
DMA-iD 3 0.15 0.31
DMA-2A(SN) 3 0.15 0.31
BR-3 3 0.15 0.31
DMA-lB 3 0.15 0.31
DMA-IC 3 0.15 0.31
BR-2 3 0.15 0.31
BR-1 3 0.15 0.31
BR-4 3 0.15 0.31
DMA-lB Payers) 3 0.15 0.31
Dr-M-11, (Pavers) 3 0.15 0.31
DMA-it 3 0.15 0.31
DMA-1A±?avers 3 0.15 0.31
[LID CONTROLS]
Type/Layer Parameters
BR-i BC
PR-1. SURFACE 7.2 0.00 0.0 0.0 5
BR-1 SOIL 18 0.4 0.2 0.1 5 5 1.5 BR-1 STORAGE 13 0.67 0.041. 0
BR-1 " DRAIN 0.3175 0.5 4 6
BR-2 BC
BR-2 SURFACE 7.2 0.00 0 0 5
BR-2 SOIL 18 0.4 0.2 0.1 5 5 1.5
BR-2 STORAGE 13 0.67 0.041 0
BR-2 DRAIN 0.4261 0.5 4 6
BR-3 BC
BR-3 SURFACE 7.2 0.00 0.0 0.0 5
BR-3 SOIL 18 0.4 0.2 0.1 5 5 1.5
BR-3 STORAGE 12 0.67 0 0
BR-3 DRAIN 0.3362 0.5 3 6
BR-4 BC
BR-4 SURFACE 7.2 0.00 0.0 0.0 5
ER-4 SOIL 13 0.4 0.2 0.1 5 5 1.5
BR-4 STORAGE 12 0.67 0 0
BR-4 DRAIN 0.4306 0.5 3 6
[LID USAGE]
Subcatchment LID Process Number Area Width InitSatur Fromlmpry ToPery Report File
BR-3 BR-3 1 557 0 0 100 0
BR-2 BR-2 1 356 0 0 100 0
BR-1 SR-1 1 803 0 0 100 0
BR-4 BR-4 1 435 0 0 100 0
[OUTFALLS
Invert Outfall Stage/Table Tide
;;Name Elev. Type Time Series Gate
DCC- 1 0 FREE NO
[STORAGE)
Invert Max. Init. Storage Curve Ponded Evap.
;;Name Elev. Depth Depth Curve Params Area Frac. Infiltration
Parameters
VAULT 0 3 0 TABULAR UBASIN 0 0
[OUTLETS]
Inlet Outlet Outflow Outlet Ocoeff! Flap
POST_DEV
Name Node Node Height Type OTable Qexpon Gate
OUTLET VAULT POD-i 0 TABULAR/HEAD OUTLET NO
(CURVES]
;;Name Type X-Value Y-Vaiue
OUTLET Rating 0.000 0.000
OUTLET 0.250 0.015
OUTLET 0.500 0.023
OUTLET 0.750 0.028
OUTLET 1.000 0.033
OUTLET 1.250 0.037
OUTLET 1.500 0.041
OUTLET 1.750 0.044
OUTLET 2.000 0.047
OUTLET 2.250 0.050
OUTLET 2.500 0.053
OUTLET 2.750 0.056
OUTLET 3.000 0.858
OUTLET 3.250 0.060
OUTLET 3.500 0.063
OUTLET 3.750 8.065
OUTLET 4.000 0.067
OUTLET 4.250 0.869
OUTLET 4.500 0.071
OUTLET 4.750 0.073
OUTLET 5.000 0.075
OUTLET 5.250 0.077
OUTLET 5.500 0.079
OUTLET 5.758 0.081
OUTLET 6.000 0.082
OUTLET 6.250 0.084
OUTLET 6.500 0.086
OUTLET 6.750 0.087
OUTLET 7.000 0.089
OUTLET 7.250 0.090
OUTLET 1.500 2.534
OUTLET 7.750 6.273
OUTLET 8.000 1.1.014
UBASIN Storage 0 1.305
UBASIN 8 1305
T IMESERI ES]
Naine Date Time Value
Oceanaide FILE "OsideRain.rn'
[REPORT]
INPUT NC
CONTROLS NC
SUBCATCHMENTS ALL
NODES ALL
LINES ALL
[TAGS]
(NAP]
DIMENSIONS -11502.645 3423.967 -5798.942 8802,155
Units None
[COORDINATES]
;;Node X-Coord Y-Coord
PCC-1 -8925.024 4095.217
VAULT -8933.210 5413.160
[VERTICES]
;;Link X-Coord Y-Coord
POST_DEV
[Polygons]
Subcatchment X-Coord
DMA -iD -8483.607
DMA-27-.(514) -60o8.201
BR-3 -8500.000
DMA-ID --10169.293
DMA-iC -6798.942
BR-2 -9761.905
BR-1 -11225.284
BR-4 -6781.305
DMA-1B(Pavers) -9547.158
DMA-ID (Pavers) -7877.219
DMA-J.E -6780.29;
DMA-IA+Pavers -11217.098
SYMEOLS]
Y-Cc,ord
7590.164
4832.451
6590.164
7631.560
7548.501
6613.757
6616.499
6634.303
7631.560
7598.816
5707.855
7656.118
;G-sge X-Coord Y-Coord
Oceanside -8509.615 8557.692
ATTACHMENT VII
EPA SWMM FIGURES AND EXPLANATIONS
Per the attached, the reader can see the screens associated with the EPA-SWMM Model in both
pre-development and post-development conditions. Each portion, i.e., sub-catchments,
outfalls, storage units, weir as a discharge, and outfalls (point of compliance), are also shown.
Variables for modeling are associated with typical recommended values by the EPA-SWMM
model, typical values found in technical literature (such as Maidment's Handbook of
Hydrology). Recommended values for the SWMM model have been attained from Appendix G
of the 2016 City of Carlsbad BMP Design Manual.
Soil characteristics of the existing soils were determined from the site specific geotechnical
investigation (located in Attachment VIII of this report).
A Technical document prepared by Tory R Walker Engineering for the Cities of San Marcos,
Oceanside and Vista (Reference [1]) can also be consulted for additional information regarding
typical values for SWMM parameters.
Manning's roughness coefficients have been based upon the findings of the "Improving
Accuracy in Continuous Hydrologic Modeling: Guidance for Selecting Pervious Overland Flow
Manning's n Values in the San Diego Region" date 2016 by TRW Engineering (Reference (61).
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I - Flc,~~ Uz0v 088 ZonLeL 1840 >Y 980 404 8731 478
PRE-DEVELOPED CONDITIONS
ij XMs4 5 PEDEVinp [Study Ariv, Mepi
Date Mar, 0
Climatology C
if. Hydiology
Hythacs
--3
i Coves
Time Series
Time Paitrw
Map Labels K?
T
C
Fdm Edit Vi Piest Re;crt Tools Window Help
29 lb 19 q k
Lut8H Psc-i
Hoperty
ime POD-i
Coordinate 2500.000
'700,000
[ escnption
Tag
Inflows NO
Treatment NO
Invert El. 0
Tide Gate NO
Tp FREE
Fixed Stage 0
urve Name
Kerres Name
Property Value
Nan-ic Ocean re
-Coordinate -9509.615
i -Coordinate 8557.692
Description
Tac
Rain Form-at INTENSITY
Time lrtery 100
:,now Catch Factor 1.0
Data Source TIMESERIES
$
Series Name Oceanside
-File Name
Station ID
Rain Jruts IN
User-assigned name of rain gage
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Oceanside
DMA-A
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Subctchnient DMA-A
Property ~ Value
Name DMA•A
><-Coordinate -848a607
Coordinate 6622 951
Description
Tag
Rain Gage Oceanside
Outlet PCIC-1
Area 371
Width 979
Slope 3
lmpery 0
Nmpery 0012
N-Pery 005
Dtoreirnpery 005
DtorePery 0,1
Zerolmpery 25
Subarea Routing OUTLET
Percent Routed 100
Infiltration GRE E NAMPT
Groundwater NO
Snor Pack
LID Controls 0
Land Uses 0
Initial Buildup NONE
Curb Length U
User-assigned name of subcatchment
tnfiItratin Editor X
lntiltration Method
Prope-ty Value
Suction Head 3
Conductivity 0.15
Initial Deficit 0.31
POST-DEVELOPED CONDITIONS
/ H
-:T <±k
Lj
Hyo
DNW1A+Pwv
U DMA, 18 D1e' DMA-l) Dt1-1C
LID Coramis U U I
OLOA
BR-3 I I
Cms -
DMA-1E
VAULT
MA-1 D
)ItA-2ASMJ
- -
OUTLET MIC
3R- -
11111 .--
A-1(Per)
k-1A.Pve*
A/Dke D
Ppit
Name P0 C-i
Cooidinate -290,792 -.
-Coocdinate 4991.922
DecripLion
Tag
IrfIov
Treatment NO
rivet El 0
Tide-Gate NO
Lpe FREE
......
the-i-assigned name of outfall
Rirr Gqe Ce rf 10 {1
kue .....................
Name Oceandde
:-Coordnate -8509.615
'-Coordinate 8557 692
Description
Tag
Rain Format INTENSITY
Time Interval 1:00
now Catch Factor 1.0
Data Source TIMESERIES
SerieT Name 0 c
File Name
- Station ID
Rain Units IN
Name of rainfall data file
r t I Sr. :tchriier,t DR-1
FIwIptity alue property Value
Name DMA1+F Li Name BR-1
',,'-Coordinate -11217.098 >2 Crjne -11225,284
f-Coordinate 7656 118 Y-Coordinate 6616 499
Description Description
Tag Tag
Rain Gage Oceanside Rain Gage Oceanside
Outlet BR-1 Outlet Vault
Area 0.726 Area 0.01843
vidrh 86 Width 10
XSlope 1 lope U
Xlmpery 61.23 lrrr Pee ry 0
N-Impery 0.012 N-lmpery 0.012
N-Pery 0,05 NPry 0,05
Dstore-lmpery 0.05 Dstore'Irnpery 005
Dstore-Pery 2.4 Dstore-Fery 0.1
2ero-lrripery 25 ero1rnpery 25
Subarea Routing PERVIOUS Subarea Routing OUTLET
Percent Routed 100 Percent Routed 100
Infiltration GREEN_AMPT Infiltration GREEN AMPT
Groundwater NO Groundwater NO
,now Pack Snow Pack
LID Controls 0 LID Controls 1
Land Uses 0 Land Uses 0
Initial Buildup NONE Initial Buildup NONE
Curb Length 0 Cb Length 0
User-assigned name of subcatchmenit
Infiltration parameters (click to edit)
[irItratton Edit '1 iinfiltration Editor
IriMtraticn Method
Property Value
Suction Head 3
Conductivity 015
Initial Deficit 0,31
Infiltration Method
Property Value
Suction Head
Conductivity 0.15
Initial Deficit 0,31
iN . lirnt rrr,.l-in
Property Value
Nanie DMA-lB
Coordinate -10169.293
'LCoordiriae 7631.560
Description
Tag
Rain Gace Oceanside
0tIei BR-2
rea 0.325
idth 71
Slope 1
lmpery 61 22
N-lrnpeni 0.012
N Pent 0,05
It riore-lrnpery 0'C6
U rlore-Pery 0.1
NZero-lmpery 25
- ubarea Routing OUTLET
Percent Routed 100
I nfiltration GRE E N_AM PT
N oundwater NO
S no, Pack
LID Controls 0
Land lJes 0
Initial Buildup NONE
C1.6 Length 0
Uaer-aiqned name of subcatchment
nv-
Property Value
Name DMA-i BEPavers]
-Coordinate -9547.158
'i-Coordinate 7631560
Description
Tag
Rain GaQe Oceanside
Outlet BR-2
.rea 0,089
/rdth 77
Slope I
lmpery 0
N-lmpery 0.012
N-Pery 0.05
['Vore-lmpery 0.05
[tore-Per- 2.4
N2ero-lmpery 25
C ubarea Routing PERVIOUS
Percent Routed 100
Infiltration GREEN_AMPT
Grourrdaatef NO
Snow Pack
LID Controlo 0
Land Uses 0
iVial Buildup NONE
Curb Length 0
User-assigned name of subratchmerut
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Infiltration Editor Infiltration Editor
nhftratiori Method Infiltration Methcnj I
Properly Value
Suction Head
Conductivity 0.15
Initial Deficit 0,31
Properly Value
Suction Head
Conducliiy 0.15
Initial Deficit 0,31
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I..0 t:l'uir t LR-2
Hupt
t arne 8R-2
-Coordinate 9761 .905
'(Coordrnate 6613 757
Description
Rain Ciae Oceanside
Outlet Vault
ea 000817
idth 10
Slope U
Impery U
N-Irnpery 0.012
NPery 0,05
Dstor&rrrpecv 0.05
Dstoe-Fery 0.1
2ero-lmpery 25
ubarea Routing OUTLET
Percent Routed 100
Infiltration GRE E N_AM PT
13roundvater NO
"now Pack
LID Controls 1
Land Uses 0
Initial Buildup NONE
Curb Length 0
User-assigned name of subcatchmerit
Ppty
Name DMA-1 Dave)
X'-Coordinate -7077,219
(Cooinate 7598.816
Description
Tag
Rain GaQe Oceanside
Outlet BR-3
Area 0,053
Width 46
Slope 1
lmpery 0
N-Impery 0.012
N-Pery 005
Dstore-lmpery 005
Dstore-Fery 2,4
2ero1mpery 25
Subarea Routing PERVIOUS
Percent Routed 100
Infiltration GREEN_AMPT
Groundwater NO
Snore Pack
LID Controls 0
Land Uses 0
Initial Buildup NONE
Curb Length 0
User-assigned name of subcatchment
Infiltration Editor X 1
Infiltration Method
property Value
Suction Head
Conductivity 0.15
Initial Deficit 0.31
Infiltration Editor X
Infiltration Method
Property Value
Suction Head
ConductiWy 0.15
Initial Deficit 0,31
luji t Drvl-1D
Property Value
Name DMA-iD
Coordinate -8483.607
Coordinate 7590.164
2 ecription
Tag
RnGage Oceanside
U 4let BR-3
crea 0,341
fidth 52
Slope 1
Impery 96.82
Nlmpery 0.012
UPery 005
Dtore-lmpery 0,05
[slore-Fery 0.1
L2ero-lmpery 25
uharea Routing OUTLET
Percent Routed 100
Infiltration GREEN AMPT
Groundwater NO
Snow Pack
LID Controls 0
Land Uses 0
lvaI Buildup NONE
rub Lenctth 0
User-assigned name of subcatchment
Infiltration Editor
Infiltration Method
Property Value
Suction Head
Conductivity 0,15
Initial Deficit 0.31
I
pert valwe
Name 8R-21
-Coordinate -8500 000
-Coornate 6590164
Description
Tag I
Rain GaQe Oceanside
Outlet Vault
Area 0,01279
Width 10
Slope U I Impery 0
lJ-Impery 0.012
N-Pew 005
[store-lmpery 005
Listore-Pery 0.1
2ero1mpery 25
uhareaRouting OUTLET
Percent Routed 100 I
Infiltration GREEN AMPT
Hroundwates NO
now Pack
LID Controb 1
Land Uses 0 I
vitial Buildup NONE
Curb Length 0
----------
User-assigned name of subcatchment
I
Infiltration Editor x
Infiltration Method
Property Value
Suction Head i3
Conductivity 015
Initial Deficit 0+31 I
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rE ti riirit 1A-1i
Mame DMA-1L
Coordinate -6798,942
Coordinate 7548. 501
Description
Tag
Rain GaQe Oceanside
Outlet BR-4
Area 0,506
Width 73
Slope 1
X Irnpery 92.52
N-Impent 0,012
N-Pery 0,05
Dstore-Irnpery 0,05
Dslore.-Pery 0.1
2ero-Irnpery 25
ubarea Routing OUTLET
Percent Routed 100
Infiltration GREEN_AM PT
Groundwater NO
Snow Pack
LID Controls 0
Land Uses 0
Initial Buildup NONE
Curb Lenath 0
User-assigned name of subcatchrnent
LI
Name BR-4j
-Coordinate -6781 305
i-Coordinate 6684.303
Description
Tag
Rain Gage Oceanside
Outlet Vault
Area 0,009986
Width 10
iSIops 0
lmpery 0
N-lmpery 0.012
N-Pery 0.05
Dstore-Impe.iv 0.05
Dstore-Peiv 0,1
2ero-lmpery 25
Subarea Routing OUTLET
Percent Routed 100
Infiltration GREEN _AMPT
Groundwater NO
Snow Pack
LID ControLs 1
Land Uses 0
Initial Buildup NONE
Curb Length 0
User-assigned name of subcatchment
Infiltration Editor X
Infiltration t1etliod F. F
Property Value
Suction Head
Conductivity 015
Initial Deficit 0.31
Infiltration Editor x
Infiltration Method
Pioperty
**
Value _J
Suction Head
ConductiWy 0.15
Initial Deficit 0.31
L t +l rr it DlA-1F
Properly Value
N rne DMA-i E
X-Coordinate -67,90,297
Y-Coordrnate 5707 855
Description
Tag
Rain liaae Oceanside
Outlet VAULT
Area 1.325
idth 124
Slope 1
lmpery 100
Nlmpery 0012
N-Pery 0.05
O Uore-lmpery 0,05
Drlore-Pery 0.1
Zero-lmpery 25
,jbarea Routing OUTLET
Percent Routed 100
Infiltration GREEN_AMPT
N-oundwater NO
now Pack
LID ControP 0
nd Ue 0
I ritral Buildup NONE
C Arb Length 0
- ---- -------------- ------- - -
User-assigned name of subcatchment
irL .i rr tit rr111 -21
Property Value
Name DMA-2.- .HI
X-Coordinate -6058,201
Y-Coordate 4832+451
Description
Tag
Rain Gage Oceanrrde
Outlet P00-1
Area 0,294
Width 128
Slope 1
lmpery 6,73
N-lmpery 0.012
N -Fery 0,05
Dstore-Impery 0.05
Ctore-Pery 0.1
Zero-lrnpery 25
subarea Routing OUTLET
Fercent Routed 100
I nliltratjn GREEN AM PT
P roundwater NO
snow Pack
LID ContioLs 0
Land Uer 0
Initial Buildup NONE
r urb Length 0
User-assigned name of subcatchment
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Infiltration Editor Infiltration Editor . X
Infiltration Method Infiltration Method
. I
Property Value
Suction Head
Conductivity 0.15
Initial Deficit 0.31
Property Value
Suction Head
Conductity 0.15
Initial Deficit 0+31
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Detention Vault
Storage Unit VAULT Storage Curse Edic L -
[operty Value Curve Name
Name VAULT Em
X-Coordinate 8933.210 Description
Coordinate 5413 160
Dscnption
T - Tag Depth Psea fff (ff2)
:InfIorvr NO U Load Treatment NO - - —
-
2 8 1305 Invert El 0
3 Save...
Max. Depth 8 .
Initial Depth 0
PoridedArea 0 5 r OK
Evap. Factor 0 6
Infiltration NO
. Cancel I
Storage Curve TABULAR .............i
Help
Coefficient 1000
Exponent 0
Conant 0 Rating Curie Ei.tc + I. *
Curve N1O Cure Name
Description
.............................................
Outlet OUTLET
... Head out Property Value )ft) (9)
Name tOUTLET a080
Inlet Node VAULT
0000 Load—
2 0.258 0.G1 5
Outlet Node POC-1
3 0.500.0,023 have...
Description —
Tag 4 0.750 0.028
Inlet Offset 0 1.000 0.033
+. ..-
Flap Gate NO 6 1.258 0.837
Rating Curve TABULAR/HEAD 1.500 .8.041 Cancel
-V
Coefficient 10.0
8 1 750
2080
8 044
.(3(347 eIp
Exponent 0.5
....,,,,..+._+.+\........................
Curve Name OUTLET
User-assigned name of outlet
EXPLANATION OF SELECTED VARIABLES
Sub Catchment Areas:
Please refer to the attached diagrams that indicate the DMA and Bio-Retention BMPs (BMP) sub areas
modeled within the project site at both the pre and post developed conditions draining to the POC.
Parameters for the pre- and post-developed models include soil type B as determined from the site
specific geotechnical investigation (attached at the end of this appendix). Suction head, conductivity
and initial deficit corresponds to average values expected for these soils types, according to Appendix G
of the 2016 City of Carlsbad BMP Design Manual.
For surface runoff infiltration values, REC selected infiltration values per Appendix G of the 2016 City of
Carlsbad BMP Design Manual corresponding to hydrologic soil type.
Selection of a Kinematic Approach: As the continuous model is based on hourly rainfall, and the time of
concentration for the pre-development and post-development conditions is significantly smaller than 60
minutes, precise routing of the flows through the impervious surfaces, the underdrain pipe system, and
the discharge pipe was considered unnecessary. The truncation error of the precipitation into hourly
steps is much more significant than the precise routing in a system where the time of concentration is
much smaller than 1 hour.
Sub-catchment BMP:
The area of biofiltration must be equal to the area of the development tributary to the biofiltration
facility (area that drains into the biofiltration, equal external area plus bio-retention itself). Five (5)
decimal places were given regarding the areas of the biofiltration to insure that the area used by the
program for the LID subroutine corresponds exactly with this tributary.
LID Usage Editor X
Control Name
Number of Replicate Units i
Area of Each Unit (sq ft or sq m( .803
of Subcatchment Occupied 100.0
Top Width of Overland Flow
Surface of Each Unit, (ft of
' Initially Saturated U
Z of Imperviouc Area Treated 100
LtD Usage Editor x
Control Name [. .
._...:....................
Number of Replicate Unite
Area of Each Unit (q It or sq m) 557
of Subcatchment Occupied 100.0
Top Width of Overland Flow
Surface of Each Unit (It or rn)
Initially Saturated . 0
of Impervious Area Treated 100
LID Usage Editor X
Control Name
Number of Replicate Units 1
Area of Each Unit (q ft or sq m) 356
of Subcatchment 0ccupd 1000
Top Width of Overland Flow
Surface of Each Unit ft or
X Initially Saturated
of Impervious Area Treated 100
LID Usage Editor X
Control Name .. ........................................1]
Number of Replicate Units 1
Area 01 Each Unit (sq ft or sq in) 435
------
of Subcatchment Occupied 1000
Top Width of Overland Flo
Surface of Each Unit (it or m)
Initially Saturated 0
%of Impervious Area Treated 100
LID ContrcEditor X
CoNfol Name
LID Type. Eo Rater Cat
Process Leyerc
Surface soil Storage Underdrairr
Storage Depth
(in. or mm)
Vegetation Volume Q
Fraction
Surface Roughness 10
thtarrnings ni
Surface Slope
(percent)
LID Control Editor x
Control Name 1
LID Type Bm-Retentajn Cell
Proces Layarc
Surface Sot Storage Urtderdrair.
Height
(in or mm)
Void Ratio I:1 (Voids / Solids)
Conductivity L............................ (in/hr or mm/is)
Clogging Factor
Note: use a Conductivity of Oil the LID
unit has an impermeable bottom.
oelp
: LID Controldtcr
Car/ret Harms
LID Type BroReter/ica Cell
Proce.o: Layers
Surface Soil Storage Urdrdrin
Thickness
(in. or mm)
Porosity 104 (volume traction)
Field Capacity lxxii:. (volume traction)
Wilting Point 1
(volume traction)
Conductivity ....... (in/hronmmihr)
Conductivity Slope [IllIIIIIIIIi.
Suction Head [1,5 1
(in or mm]
Help
LID Control Editor X
ContrI Name
LID Type EtoHetentron Cell
Process Layarrm
Surface Soil Storage Undendrarn
Drain Coefficient 10.3175
(in/hr or mm/is]
Drain Exponent EIIIIIIIIIIlII1
Drain Offset Height
(in or mm]
LID Control Editor Xi
CorroI Name,
U) Type Sic Rereryion
Pr xerr tyer
Surface SOjj Store Underdrn
Storage Depth 1 (in. or mm)
Vegetation Volume
Fraction
Surface Roughness
Mannings n) ------------------
Surface Slope [uIIII1IJ
LID Control Salter X
Cctrci Name
LID Type: Reerin Cell
Pioces: Layer
Surface Soil Storage Underdiern
(in, or mm)
Porosity, 0.4
(volume traction)
Field Capacity F0.2 [volume fraction)
Wilting Point 0.1
(volume fraction)
Condictivity
(in/hrormm/hr) "" ........
Conthctivity Slope
Suction Head 5
(in or mm)
UDControl Editor X
o:troI Name
LIC Type -
Picceso Leis.
S.efece Soil Storage Underdreir,
H eight
Void Ratio
(Voids / Solids)
Conductivity
(in/hr or mm/hr) ........
Clogging Factor ZTIIIII1
Note: use a Conductivity of 0 i the LID
unit has an impermeable bottom.
LID Control Editor X
Corrtroi Name
LID Type SicRetenton Cell
Process Lasers'
Surface Soil Siorege Underdrarn
ran .,Uc,IIkIc3R lLJ.4.b1
(in/hr or mm/fir)
Drain Exponent
Drain Offset Height
(eiormm)
Note: use a Drain Coefficient of 0 if the
UP unit has no underdrain,
Hp
UO Control Editor X
Control Name,
LID Type Eo Rerention C
Froce Leyer
uiface 561 Storage Undeidrein
Storage Depth i721 (in. or mm)
Vegetation Volume
Fraction
Surface Roughness EoiITX1 tvfannings n)
Surface Slope
(percent)
LID Control Editor x
Control Name ..-
LID Type oReIenIion Cad
Proces Laysis.
Surface Sad Storage Uraderdar
Height 112
fin, or mm)
IIiIIIIIII1 (Voids / Solids)
Conductivity
(in/hr or mm/hi) L ..............
Clogging Factor LTiiIIJ
Note; use a Conductivity of 0 if the LID
unit has an impermeable bottom.
LID Control Editor X
Control Name
LID Type: BrmRerenlion C
Procem Layer
Surface Soil Storage Urdeidrarn =
Porosity 0.4
(volume fraction)
Field Capacity [.0.2 IIIiII] (volume fraction)
Wilting Point
(volume fraction)
Conductivity
(in/hr or mm/hi) .-. ................
Conductivity Slope
Suction Head [i
LID Control Editor X
CcntrdNam
LID Type Bic-Retention Cad
Procecc Layers.
Surtce Sad Storage lJnderdrain
Drain Coefficient
(inihr or mm/hi)
Drain Exponent [5IIIIIII1]
Drain Offset Height
(inormm)
Note; use a Drain Coefficient of 0 if the
LID unit has no underdrain.
flt Carrc.e.l
(in. or mm)
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Control Name
LID Type: Bio.Rere Pr
Pa:e: Layerr.
Surface Soil Stoage Underdiain
Storage Depth
(in, or firm)
Vegetation Volume [o 'i
Fraction
Surface Roughness
[Mannings n)
Surface Slope 0.0
(percent)
LID Control Editor X
Control Name
LID Type: SioiRetr-/icrr Get
Proce: Lmrerr
Surface Soil Storage Urrdrmn
Thickness
(in. or mm)
Porosity
.... 4
(volume fraction)
0.2 Field Capacity
(volume traction)
Wilting Point
(volume traction)
Conductivity
(in/hr or mm/hi)
Conductivity Slope
Suction Head [5 "] (inormm)
LID Control itor X
Coritol Name
LID Type Bio .ir -
Procer Layerc
Surface Soil Storage LIrdedrmn
ClJhir mm)
Void Patio
(Voids /Sohds)
Coridudivity, [IIIII1 (in/hr or mm/hr)
Clogging Factor CI j
Note: use a Conductivity of 0 it the LID
unit has an impermeable bottom.
LID Control Editor X
Control Name:
LlDlirpe. Sic-Pete Ci'l
Proce:" Layers:
Surface Soil Storage Undardrairr
Drain Coefficient (ir/hr or mm/hi)
Drain Exponent F6-5
Drain Offset Height 13
(in. or ram)
Note: use a Drain Coefficient of Of the
LID unit has no unde;drain.
[1K C~3j 11
LID Control Editor: Explanation of Significant Variables
Storage Depth:
The storage depth variable within the SWMM model is representative of the storage volume
provided beneath the surface riser outlet and the surface of the bio filtration facility.
In those cases where the surface storage has a variable area that is also different to the area of
the gravel and amended soil, the SWMM model needs to be calibrated as the LID module will
use the storage depth multiplied by the BMP area as the amount of volume stored at the
surface.
Let ABMP be the area of the BMP (area of amended soil and area of gravel). The proper value of
the storage depth SD to be included in the LID module can be calculated by using geometric
properties of the surface volume. Let A0 be the surface area at the bottom of the surface pond,
and let Ai be the surface area at the elevation of the invert of the first row of orifices (or at the
invert of the riser if not surface orifices are included). Finally, let hi be the difference in
elevation between A0 and A. By volumetric definition:
ABMP SD = (A0+A1) h1
2 (1)
Equation (1) allows the determination of SD to be included as Storage Depth in the LID module.
The 3-inches of gravel volume (3-inches x volume of solids (0.6) = 1.8-inches) is then subtracted
from this volume.
Porosity: A porosity value of 0.4 has been selected for the model. The amended soil is to be
highly sandy in content in order to have a saturated hydraulic conductivity of approximately 5
in/hr.
REC considers such a value to be slightly high; however, in order to comply with the HMP
Permit, the value recommended by the Copermittees for the porosity of amended soil is 0.4,
per Appendix A of the Final Hydromodification Management Plan by Brown & Caldwell, dated
March 2011. Such porosity is equal to the porosity of the gravel per the same document.
Void Ratio: The ratio of the void volume divided by the soil volume is directly related to
porosity as n/(1-n). As the underdrain layer is composed of gravel, a porosity value of 0.4 has
been selected (also per Appendix A of the Final HMP document), which results in a void ratio of
0.4/(1-0.4) = 0.67 for the gravel detention layer.
Conductivity: Per the site-specific geotechnical investigation for the project site infiltration is
only feasible for basins to the east of the project site, a factored infiltration rate of 0.041 in/hr
has been used for these facilities. For the western basins, a value of 0 has been assigned for
conductivity accordingly.
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C/caging factor: A clogging factor was not used (0 indicates that there is no clogging assumed
within the model). The reason for this is related to the fairness of a comparison with the SDHM
model and the HMP sizing tables: a clogging factor was not considered, and instead, a
conservative value of infiltration was recommended.
Drain (Flow) coefficient: The flow coefficient C in the SWMM Model is the coefficient needed to
transform the orifice equation into a general power law equation of the form:
q=C(H—H0)n (2)
where q is the peak flow in in/hr, n is the exponent (typically 0.5 for orifice equation), H0 is the
elevation of the centroid of the orifice in inches (assumed equal to the invert of the orifice for
small orifices and in our design equal to 0) and H is the depth of the water in inches.
The general orifice equation can be expressed as:
- ir D2 ~2,9 QCg 144
where Q is the peak flow in cfs, D is the diameter in inches, cg is the typical discharge coefficient
for orifices (0.61-0.63 for thin walls and around 0.75-0.8 for thick walls), g is the acceleration of
gravity in ft/s2, and H and H0 are defined above and are also used in inches in Equation (3).
It is clear that:
q () X ABMp
12X%O0 = Q (cfs) (4)
Cut-Off Flow: 0 (cfs) and q (in/hr) are also the cutoff flow. For numerical reasons to insure the
LID is full, the model uses cut-off = 1.01 Q.
(3)
Overland Flow Manning's Coefficient per TRWE (Reference [6])
appeal of a de facto value, we anticipate that jurisdictions will not be inclined to approve land surfaces
other than short prairie grass. Therefore, in order to provide SWMM users with a wider range of land
surfaces suitable for local application and to provide Copermittees with confidence in the design
parameters, we recommend using the values published by Yen and Chow in Table 3-5 of the EPA SWMM
Reference Manual Volume I - Hydrology.
SWMM-Endorsed Values Will Improve Model Quality
In January 2016, the EPA released the SWMM Reference Manual Volume I - Hydrology (SWMM
Hydrology Reference Manual). The SWMM Hydrology Reference Manual complements the SWMM 5
User's Manual and SWMM 5 Applications Manual by providing an in-depth description of the program's
hydrologic components (EPA 2016). Table 3-5 of the SWMM Hydrology Reference Manual expounds
upon SWMM 5 User's Manual Table A.6 by providing Manning's n values for additional overland flow
surfaces3. The values are provided in Table 1:
Table 1: Manning's n Values for Overland Flow (EPA, 2016; Yen 2001; Yen and Chow, 1983).
Overland Surface Light Rain
(<0.8 in/hr)
Moderate Rain
(0.8-1.2 in/hr)
Heavy Rain
(>1.2 in/hr)
Smooth asphalt pavement
Smooth impervious surface
0010
0.011
0.012
0.013
0.015
0.015
Tar and sand pavement 0,012 0.014 0,016
Concrete pavement 0.014 0.017 0.020
Rough impervious surface 0.015 01019 0.023
Smooth bare packed soil 0.017 0.021 - 0.025
Moderate bare packed soil 0.025 0.030 0.035
Rough bare packed soil 0.032 0.038 0.045
Gravel soil 0.025 0.032 0.045
Mowed poor grass 0.030 0.038 0.045
Average grass, closely clipped sod 0.040 0.050 0,060
Pasture 0.040 0.055 0.070
Timberland 0.060 0.090 0.120
Dense grass 0.060 0.090 0.120
Shrubs and bushes 0.080 0.120 0.180
Land Use
Business 0.014 0.022 0.035
Semibusiness 0.022 0.035 0.050
Industrial 0.020 0.035 0.050
Dense residential 0.025 0.040 0.060
Suburban residential
Parks and lawns
0.030
0.040
0.055
0.075
0.080
0.120
For purposes of local hydromodification management BMP design, these Manning's n values are an
improvement upon the values presented by Engman (1986) in SWMM S User's Manual Table A.6. Values
from SWMM 5 User's Manual Table A.6, while completely suitable for the intended application to
certain agricultural land covers, comes with the disclaimer that the provided Manning's n values are
valid for shallow-depth overland flow that match the conditions in the experimental plots (Engman,
Further discussion is provided on page 6 under "Discussion of Differences Between Manning's n Values"
ATTACHMENT VIII
Geotechnical Documentation
LIM
Hydrologic Sot Group—San Diego County Area, California
MAP LEGEND MAP INFORMATION
Area of Interest (AOl) o C The soil surveys that comprise your AOl were mapped at
Area of Interest (AOl) J3 CID
1:24,000.
Soils o Warning: Soil Map may not be valid at this scale.
Soil Rating Polygons
""'" A L_J 0 Not rated or not available Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
Lii ND Water Features line placement. The maps do not show the small areas of
Streams and Canals contrasting soils that could have been shown at a more detailed Li B scale. Transportation LI BID *44 Rails Please rely on the bar scale on each map sheet for map
Li C
.. Interstate Highways measurements.
Li C/I) US Routes Source of Map: Natural Resources Conservation Service
Li DWeb Soil Survey URL:
Major Roads Coordinate System: Web Mercator (EPSG:3857)
Li Not rated or not available Local Roads Maps from the Web Soil Survey are based on the Web Mercator
Soil Rating Lines Background projection, which preserves direction and shape but distorts
A Aerial Photography distance and area, A projection that preserves area, such as the IN Albers equal-area conic projection, should be used if more AID accurate calculations of distance or area are required.
B This product is generated from the USDA-NRCS certified data as
B/D of the version date(s) listed below.
Soil Survey Area: San Diego County Area, California
Survey Area Data: Version 13, Sep 12, 2018
C/I) Soil map units are labeled (as space allows) for map scales
I) 1:50000 or larger.
Not rated or not available Date(s) aerial images were photographed: Nov 3, 2014—Nov
Soil Rating Points 22, 2014
A The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background 0 ND imagery displayed on these maps. As a result, some minor
B . shifting of map unit boundaries may be evident.
B/D
USDA Natural Resources Web Soil Survey 7/19/2019
Conservation Service National Cooperative Soil Survey Page 2 of 4 - - - - - - - - - - - - - - M - - -
Hydrologic Soil Group—San Diego County Area, California
Hydrologic Soil Group
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 (ND, BID, 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 (AID, B/D, or CID), 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.
Q Natural Resources Web Soil Survey 7/19/2019
Conservation Service National Cooperative Soil Survey Page 3 of 4
Hydrologic Soil Group—San Diego County Area, California
Rating Options
Aggregation Method: Dominant Condition
Component Percent Cutoff. None Specified
Tie-break Rule: Higher
uo Natural Resources Web Soil Survey 7119/2019
Conservation Service National Cooperative Soil Survey Page 4 of 4
ATTACHMENT IX
Summary Files from the SWMM Model
PRE_DEV
EPA STORM WATER MANAGEMENT MODEL - VERSION 5.0 (Build 5.0.022) --------------------------------------------------------------
* * * * * * * * **.*+. * * * * * * * * * * * *+ * * * * * * * * * * * * * * * * * * * * * * * k* * * * * *
NOTE: The summary statistics displayed in this report are
based on results found at every computational time step,
not lust on results from each reporting tine step.
* * * * * * * * * .* .* * * A, * 'A
Analysis Options.
****** **********
Flow Units ...............CFS
Process Models:
Rainfall/Runoff ........YES
Snowmeit ...............NO
Groundwater ............NO
Flow Routing ...........NO
Water Quality ..........NO
Infiltration Method ......GREEN AMPT
Starting Date ............00T-01-1951 00:00:00
Ending Date ....... ....... SEP-30-2038 23:00:00
Antecedent Dry Days ......0.0
Report Tine Step .........01:00:00
Wet Time Step ............00:15:00
Dry Time Step ............04:00:00
Volume Depth
Runoff Quantity Continuity
** * ** * ** * 'A •***. *• *•* * * A * * ****-*
acre-feet inches
Total Precipitation 208.490 674.360
Evaporation Lose 0.768 2.485
Infiltration Lose 197.677 639.388
Surface Runoff 10.899 3..2.51
Final Surface Storage 0.000 0.000
Continuity Error (%) -0.410
Volume Volume
- Flow Routing Continuity acre-feet 10"6 gal.
Dry Weather Inflow 0.000 0.000
Wet Weather Inflow 101899 3.551
Groundwater Inflow 0.000 0.008
ROIl Inflow ..............0.000 0.000
External Inflow 0.000 0.000
External Outflow 10.899 3.5.51
Internal Outflow 0.000 0.000
Storage Losses 0.000 0.000
initial Stored Volume . . . 0.000 0.000
Final Stored Volume ..... 0.000 0.000
Continuity Error (I) 0.000
***t**********W** ***w**** **
Subcatchment Runoff Summary
** *** * * * ******* * ** ****t
Total Total
--------------------------------------------------------------------------------------------------------
Total Total Total Total Peak Runoff
Precip Nunon Evap infil Runoff Runoff Runoff Coeff
Subcatchneat in in in in in 10"6 gal CFS
DMA-A 634.36 0.00 2.48 639.39 35.25 3.55 3.91 0.052
Analysis begun on: Tue Jul 16 12:54:08 2019
Analysis ended on: Tue Jul 16 12:54:24 2019
Total elapsed time: 00:00:16
POST_DEV
EPA STORM WATER MANAGEMENT MODEL - VERSION 5.0 (Build 5.0.022) --------------------------------------------------------------
NOTE: The summary statistics displayed in this report are
based on results found at every computational time step,
not just on results from each reporting time step.
Analysis Options
Flow Units ...............OWE
Process Models:
Rainfall/Runoff ........YES
Snowrnelt ...............NO
Groundwater ............NO
Flow Routing ...........YES
Ponding Allowed ........NO
Water Quality ..........NO
Infiltration Method ......GREEN AMPT
Flow Routing Method ......KINWAVE
Starting Date ......... ...00T-01-1951 00:00:00
Ending Date ..............SEP-30-2008 23:00:00
Antecedent Dry Days ......0.0
Report Time Step .........01:00:00
Met Time Step ............00:15:00
Dry Time Step ............04:00:00
Routing Time Step ........60.00 sec
Volume Depth
Runoff Quantity Continuity acre-feet inches
Total Precipitation 208.398 674.360
Evaporation Loss 22.933 74.210
Infiltration Loss 70.572 228.365
Surface Runoff ...........116.713 377.673
Final Surface Storage ... 0.000 0.000
Continuity Error ( -0.873
Volume Volume
Flow Routing Continuity acre-feet 106 gal
Dry Weather Inflow 0.000 0.000
Wet Weather Inflow 116.713 36.033
Groundwater Inflow 0.000 0.000
ROIl Inflow ..............0.000 0.000
External Inflow 0.000 0.000
External Outflow 116.685 38.023
Internal Outflow 0.000 0.000
Storage Losses 0.000 0.000
Initial Stored Volume . . . 0.000 0.000
Final Stored Volume 0.000 0.000
Continuity Error Ct) 0.024
Highest Flow Instability Indexes
****** t*********** *** ******* 4*
All links are stable.
* * * * * * * 44 * * * * * * * * * * * * -* * * A.
Routing Time Step Summary
Minimum Time Step : 60.00 sec
Average Time Step : €0.00 sec
POST_DEV
Maximum Time Ste? : 60.00 sec
Percent in Steady State : 0.00
Average Iterations per Step : 1.00
** *******k,***,*******
Subcatchment Runoff Summary
Total Total
--------------------------------------------------------------------------------------------------------
Total Total Total Total Peak Runoff
Precip Runon Evan miii Runoff Runoff Runoff Coeff
Subcatchment in in in in in 10"6 gal CFS
DMA-iD 674.36 0.00
---------------------------------------------------------------------------------------------------------
81.95 21.50 577.72 5.35 0.41 0.857
DMA-2A(SM) 674.36 0.90 6.88 596.04 74.05 0.59 0.31 0.110
BR-3 674.36 15402.89 822.89 0.00 15312.70 5.32 0.42 0.952
DMA-lB 674.36 9.00 50.94 247.65 382.23 3.37 0.37 0.567
DMA-iC 674.36 0.90 78.35 47.62 555.20 7.63 0.60 0.823
BR-2 674.36 15205.17 694.80 2950.69 13156.94 2.92 0.38 0.829
BR-1 674.36 557.47 412.72 276.03 546.16 0.27 0.74 0.443
BR-4 674.36 28132.37 871.74 0.00 28059.63 7.61 0.62 0.974
DMA-iB(Pavers) 674.36 0.00 2.27 672.29 0.01 9.90 0.90 0.090
DMA-1D(?avers) 674.36 0.99 2.27 672.29 0.01 0.09 0.00 0.000
DMA-1E 674.36 0.99 87.11 0.00 592.58 21.32 1.60 0.879
01,!A-IA±Favers 674.36 0.00 56.17 609.37 14.15 0.28 0.83 0.021
LID Performance Summary
Total
------------------------------------------------------------------------------------------------------------------
Evap Infil Surface Drain Init. Final Pont.
Inflow Loss Loss Outflow Outflow Storage Storage Error
Suhcatchment LID Control in in in in in in in
BR-3 ER-3 16077.25
------------------------------------------------------------------------------------------------------------------
823.12 0.00 2641.89 12675.01 0.00 0.09 -0.39
BR-2. BR-2 15879.53 694.60 2950.11 2268.89 10884.29 0.00 0.00 -0.12
BR-1 BR-1 1231.83 412,64 275.98 220.41 325.64 0.00 9.09 -0.23
BR-4 BR-4 28806.73 871.75 0.00 9388.01 18672.01 0.00 0.09 -0.43
Node Depth Summary
---------------------------------------------------------------------
Average Maximum Maximum Time of Max
Depth Depth HG-1 Occurrence
Node Type Feet Feet Feet days hr:min
POC-1 OUTFALL
---------------------------------------------------------------------
0.00 0.00 9.90 0 09:00
VAULT STORAGE 0.12 7.56 7.56 18823 17:01
Node Inflow Summary
---------------------------------------------------------------------------------------
M5ximum Maximum Lateral Total
Lateral Total Time of Max inflow inflow
Inflow inflow Occurrence Volume Volume
Node Type CFS CFS days hr:mi.n 106 gal 106 gal
POC-1 OUTFALL
-------------------------------------------------------------------------------------
0.31 3.79 18823 17:09 0.591 38.021
VAULT STORAGE 3.41 3.41 18823 17:09 37.439 37.439
***************,,******
Node Surcharge Summary
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* ** * * * * * * *** * ** * * * ** * *
Surcharging occurs when water rises above the top of the highest conduit. ---------------------------------------------------------------------
Max. Height Mm. Depth
Hours Above Crown Below Rim
Node Type Surcharged Feet Feet ---------------------------------------------------------------------
VAULT STORAGE 499679.02 7.558 0.442
** ** * * * t ** * * * * *
Node Flooding Summary
****** ** * n*** **** **t
No nodes were flooded.
* * * -* .* * * * * * .* * * * * * * * * A. * .*
Storage Volume Summary
Average
------------------------------------------------------------------
Avg E&l Maximum Max
Volume Pcnt Pcnt Volume Pcnt
Storage Unit 1000 ft3 Full Loss 1000 ft3 Full
VAULT 0.151
------------------------------------------------------------------
1 0 9.864 94
**** ** ** * *** ****** *****
Outfall Loading Summary
-----------------------------------------------------------
Flow Avg. Max. Total
Freq. Flow Flow Volume
Outfall Node Pcnt. CFS CFS 106 gal
POC-1 9.66 0.03 3.70 38.021 -----------------------------------------------------------
System 9.66 0.03 3.70 38,021
----------------------
Time of Max Maximum
Occurrence Outflow
days hr:rrun CFS ----------------------
18823 17:00 3.40
Link Flow Summary
Maximum Time of Max Maximum Max! Max!
.Flowj Occurrence Veloci Full Full
Link Type CFS days hr:min ft/sac Flow Depth
OUTLET DUMMY 3.40 18823 17:01
*44*4* *******************
Conduit Surcharge Summary
No conduits were surcharged.
Analysis begun on: Mon Dec 16 16:34:54 2019
Analysis ended on: Mon Dec 16 16:35:21 2019
Total elapsed time: 00:00:27
Priority Development Project (PDP) SWQMP
BMW of Carlsbad
CO
M40L tnrdl
P.eBUrce
ATTACHMENT 3
Structural BMP Maintenance Information
Use this checklist to ensure the required information has been included in the Structural
BMP Maintenance Information Attachment:
Preliminary Design/Planning/CEQA level submittal:
Attachment 3 must identify:
El Typical maintenance indicators and actions for proposed structural BMP(s) based on
Section 7.7 of the BMP Design Manual
Final Design level submittal:
Attachment 3 must identify:
Specific maintenance indicators and actions for proposed structural BMP(s). This shall be
based on Section 7.7 of the BMP Design Manual and enhanced to reflect actual proposed
components of the structural BMP(s)
How to access the structural BMP(s) to inspect and perform maintenance
Features that are provided to facilitate inspection (e.g., observation ports, cleanouts, silt
posts, or other features that allow the inspector to view necessary components of the
structural BMP and compare to maintenance thresholds)
Manufacturer and part number for proprietary parts of structural BMP(s) when applicable
Maintenance thresholds for BMPs subject to siltation or heavy trash(e.g., silt level posts or
other markings shall be included in all BMP components that will trap and stc-re sediment,
trash, and/or debris, so that the inspector may determine how full the BMP is, and the
maintenance personnel may determine where the bottom of the BMP is. If required, posts
or other markings shall be indicated and described on structural BMP plans.)
Recommended equipment to perform maintenance
When applicable, necessary special training or certification requirements for inspection and
maintenance personnel such as confined space entry or hazardous waste management
PDP SWQMP 25 of 27
Priority Development Project (PDP) SWQMP
BMW of Carlsbad
COMOML
Summary of BMP Inspection/Maintenance
BMP Reponsible Inspection! Maintenance Minimum Frequency
Party(s) Activities Required of Activities
Biofiltration Inspect for and remove accumulated Maintain at least once
Basin wl Partial trash, sediment, and debris as necessary. per year. Inspect at least
Retention Project Inspect for poor vegetation establishment twice per year, prior to
Owner or erosion, and overgrown vegetation, start of rainy season
BMP No. I Inspect for standing water and repair or (Oct. 1st) and after
BMP No. 2 de-clog as needed. significant storm events.
Biofiltration Inspect for and remove accumulated Maintain at least once
Basin trash, sediment, and debris as necessary. per year. Inspect at least
Project Inspect for poor vegetation establishment twice per year, prior to
BMP No. 3 Owner or erosion, and overgrown vegetation, start of rainy season
BMP No. 4 Inspect for standing water and repair or (Oct. 1st) and after
de-clog as needed. significant storm events.
Maintain at least once
Modular Inspect for and remove accumulated per year. Inspect at least
Wetland System Project trash, sediment, and debris as necessary. twice per year, prior to
Owner Clear obstructions if standing water or start of rainy season
BMP No. 5 inlet clogged. (Oct. 1st) and after
significant storm events.
Underground Maintain at least once
Detention Inspect for and remove accumulated per year. Inspect at least
System Project trash, sediment, and debris as necessary. twice per year, prior to
Owner Clear obstructions if standing water or start of rainy season
BMP No. 6 inlet clogged. (Oct. 1st) and after
significant storm events.
PDP SWQMP 26of27 I
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'fi ts 'tj'iflL'flt
dchi-s
Rcriit :i'd flpcd\ p)m f .ic& :ritiLiir'ti wIIiuut
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Chapter 7: Long Term Operation and Maintenance
svale in Appendix E.15)*. The vegetated BMP may or may not include amended soils, subsurface
gravel layer, underdrain, and./or impermeable liner. The project civil engineer is responsible for
determining which maintenance indicators and actions shown below are applicable based on the
components of the structural. BMP.
TABLE 7-2. Maintenance Indicators and Actions for Vegetated BMPs
\flCiliiuIt FId:ifti': FL cc(i, i}Imi, i -t.di:di \ YIIII)II ir ric:ii11 nliiiu
()\uisn \c:Itiltsfl \is's; ur ifllVi :i :iTimr'I( Nifl flfll (S IIi:ifl iFL ksin Pcht itt
Ilic ' ctc fl pci r:iiIIi: i'i:iu \ mn IIc,sHic cl i.
cit ill If r III:' ,I flllflln :flfl \ c lctIi,fl
Erosion due to concentrated irrigation Repair/re-seed/re-plant eroded areas and adjust the i rn nation
flow system.
flIt fl inn It c(nccnrr:lni flurni Rrpinr rc.c cii c Him ciuind niu:i', JI d ii ic :Iitpusr inc
unutt tlts'i c)rrcct\ fl:.1'ulc ,cui i id nc ifiIfl cuntrui Ini,cit,
Isilc Ill flu" LIlfl' p'tII1K, stI fltlfl'si ft n,1flfli si
nIper (irallsitc iccisislitin ss tii,iI plin. ii iFLsnc fi nut
Cs s sCiCsi i)\ icriflriflJ us h\1P Is Pc iflCfls:ii din ITusi r:Rlr,
(.ui\ I ri mcd Iiii In: C n:tictyl pr: n is inc :idditissn:ii rcilnuiin fir
1cm 'Ii tr:ic'
Standing water in vegetated swales used Make appropriate corrective measures such as adjusting irrigation
for pretreatment and/or site design. system, removing obstructions of debris or invasive vegetation,
BMPs loosening or replacing top soil to allow for better infiltration, or
minor re-grading for proper drainage, if the issue is not corrected
by restoring the BMP to the original plan and grade, the City
Engineer shall be contacted prior to any additional repairs or
reconstruction.
iiniitii: \mflcr iii i'l )rcuii'ius ,':, \ltLc ;ippsfisprdilC (s)rrcct]\ c flIt u.tircs ruch
list It i in \ fi ii ii t ' ii I I ii ci fi im is n sri t inn iii id 1 It fi fiS r In fi I
isiltritsu ircm, 'n flss' tiwtnHi rnlnsuitin I)nIruct5ssn st dchri' 5 51 lii's misc cni'Inns,n, cicirns
r hss,i'' fur I dIn is Insi i indmIr.iin. Pt 11c 1-c tppI:cusk:. m pllnci rcpl.sdlcic ci it
fiiiiss\d:nn 1 Slisrili ccnnl Csr.:p;cIci tssik,
Obstructed inlet or outlet structure Clear obstructions.
l)5im:fc Is nlrricttir ii Cs siliftint It sicIi Rnp.in fir Is]uccin;ippilsnldc.
in ',cc:rl 1*1 sr mulct 'itrtuctnrn
**These BMPs typically include a surface ponding layer as part of their function which may take 96 hours to
drain following a storm event.
Vegetated swales and flow-through planter boxes in regards to flow-thru treatment control BMPs are not options as
structural BMPs. Carlsbad has not adopted. an Alternative Compliance Program.
7-8 February 2016
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Chapter 7: Long Term Operation and Maintenance
TABLE 7-5. Maintenance Indicators and Actions for Detention BMPs
Overgrown vegetation
T rosion clue to concentrated storm Repair/re-seed/re-plant eroded areas and make appropriate
water runoff flow corrective measures such as adding erosion control blankets, adding
stone at flow entry points, or re-grading where necessary.
.i I
Make appropriate corrective measures such as adjusting irrigation
Standing water system, removing obstructions of debris or invasive vegetation, or
minor re-grading for proper drainage.
Damage to structural components such
as weirs, inlet or outlet structures Repair or replace as applicable.
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7-11 February 2016
Inspection Summary
Inspect Pre-Treatment, Biofiltration and Discharge Chambers - average inspection interval is 6 to
12 months.
(15 minute average Inspect/on t,'ne,
NOTE: Pollutant loading varies greatly from site to site and no two sites are the same. Therefore,
the first year requires inspection monthly during the wet season and every other month during the
dry season in order to observe and record the amount of pollutant loading the system is receiving.
System Diagram
Access to separation chamber aid pre-filter cartridges
Pre-treatment Chamber
2) Biofiltration Chamber
:) Discharge Chamber
Access to discharge chamber and orifice control
/
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A
M c.. U L A R
Inspection Overview
As with all stormwater BMPs inspection and maintenance on the MWS Linear is necessary.
Stormwater regulations require that all BMPs be inspected and maintained to ensure they are
operating as designed to allow for effective pollutant removal and provide protection to receiving water
bodies. It is recommended that inspections be performed multiple times during the first year to assess
the site specific loading conditions. This is recommended because pollutant loading and pollutant
characteristics can vary greatly from site to site. Variables such as nearby soil erosion or construction
sites, winter sanding on roads, amount of daily traffic and land use can increase pollutant loading on
the system. The first year of inspections can be used to set inspection and maintenance intervals for
subsequent years to ensure appropriate maintenance is provided. Without appropriate maintenance a
BMP will exceed its storage capacity which can negatively affect its continued performance in
removing and retaining captured pollutants.
Inspection Equipment
Following is a list of equipment to allow for simple and effective inspection of the MWS Linear:
. Modular Wetland Inspection Form
Flashlight
Manhole hook or appropriate tools to remove access hatches and covers
Appropriate traffic control signage and procedures
Measuring pole and/or tape measure.
Protective clothing and eye protection.
7/16" open or closed ended wrench.
Large permanent black marker (initial inspections only - first year)
Note: entering a confined space requires appropriate safety and certification. It is generally not
required for routine inspections of the system.
www.modularwetlandscom
M 0 D U L A R
\JF)S
Inspection Steps
The core to any successful stormwater BMP maintenance program is routine inspections. The
inspection steps required on the MWS Linear are quick and easy. As mentioned above the first year
should be seen as the maintenance interval establishment phase. During the first year more frequent
inspections should occur in order to gather loading data and maintenance requirements for that
specific site. This information can be used to establish a base for long term inspection and
maintenance interval requirements.
The MWS Linear can be inspected though visual observation without entry into the system. All
necessary pre-inspection steps must be carried out before inspection occurs, especially traffic control
and other safety measures to protect the inspector and near-by pedestrians from any dangers
associated with an open access hatch or manhole. Once these access covers have been safely
opened the inspection process can proceed:
Prepare the inspection form by writing in the necessary information including project name,
location, date & time, unit number and other info (see inspection form).
. Observe the inside of the system through the access hatches. If minimal light is available and
vision into the unit is impaired utilize a flashlight to see inside the system and all of its
chambers.
. Look for any out of the ordinary obstructions in the inflow pipe, pre-treatment chamber,
biofiltration chamber, discharge chamber or outflow pipe. Write down any observations on the
inspection form.
Through observation and/or digital photographs estimate the amount of trash, debris and
sediment accumulated in the pre-treatment chamber. Utilizing a tape measure or measuring
stick estimate the amount of trash, debris and sediment in this chamber. Record this depth on
the inspection form.
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Through visual observation inspect the condition of the pre-filter cartridges. Look for excessive
build-up of sediments on the cartridges, any build-up on the top of the cartridges, or clogging
of the holes. Record this information on the inspection form. The pre-filter cartridges can
further be inspected by removing the cartridge tops and assessing the color of the
BioMediaGREEN filter cubes (requires entry into pre-treatment chamber - see notes above
regarding confined space entry). Record the color of the material. New material is a light green
in color. As the media becomes clogged it will turn darker in color, eventually becoming dark
brown or black. Using the below color indicator record the percentage of media exhausted.
New Exhausted
RinMc1taRFFN _______ BioMediaGREEN
0% -- Percent Clogged -- 100%
The biofiltration chamber is generally maintenance free due to the system's advanced pre-
treatment chamber. For units which have open planters with vegetation it is recommended that
the vegetation be inspected. Look for any plants that are dead or showing signs of disease or
other negative stressors. Record the general health of the plants on the inspection and
indicate through visual observation or digital photographs if trimming of the vegetation is
needed.
The discharge chamber houses the orifice control structure, drain down filter and is connected
to the outflow pipe. It is important to check to ensure the orifice is in proper operating
conditions and free of any obstructions. It is also important to assess the condition of the drain
down filter media which utilizes a block form of the BioMediaGREEN. Assess in the same
manner as the cubes in the Pre-Filter Cartridge as mentioned above. Generally, the discharge
chamber will be clean and free of debris. Inspect the water marks on the side walls. If possible,
inspect the discharge chamber during a rain event to assess the amount of flow leaving the
system while it is at 100% capacity (pre-treatment chamber water level at peak HGL). The
water level of the flowing water should be compared to the watermark level on the side walls
which is an indicator of the highest discharge rate the system achieved when initially installed.
Record on the form is there is any difference in level from watermark in inches.
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M 0 D U L A R
W TLANJDS
NOTE: During the first few storms the water level in the outflow chamber should e observed
and a 6" long horizontal watermark line drawn (using a large permanent marker) ci the water
level in the discharge chamber while the system is operating at 100% capacity. The diagram
below illustrates where a line should be drawn. This line is a reference point for future
inspections of the system:
Using a permanent marker draw a 6 inch long horizontal the, as shown, a: The
All- higher water level in the MVVS Linear discharge chamber.
Water level in the discharge chamber s a function of flow rate and pipe size. 0bsrvation of
water level during the first few months of operation can be used as a benchmark level for
future inspections. The initial mark anc all future observations shall be made when system is
at 100% capacity (water level at maximum level in pre-treatment chamber). If futura water
levels are below this mark when system is at 100% capacity this is an indicator that
maintenance to the pre-filter cartridges may be needed.
41 Finalize inspection report for analysis by the maintenance manager to determine if
maintenance is required.
www.modutarwetlands.com
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Maintenance Indicators
Based upon observations made during inspection, maintenance of the system may be required based
on the following indicators:
Missing or damaged internal components or cartridges.
Obstructions in the system or its inlet or outlet.
Excessive accumulation of floatables in the pre-treatment chamber in which the lengti and
width of the chamber is fully impacted more than 18".
Excessive accumulation of sediment in the pre-treatment chamber of moe than 6" in depth.
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I I
M 0 ) U L A R
WET LANDS
Excessive accumulation of sediment on the BioMediaGREEN media housed within the pie-
filter cartridges. The following chart shows photos of the condition of the BioMeiiaGREEN
contained within the pie-filter cartridges. When media is more than 85% cloggec replacement
is required.
New Exhausted
BioMediaGREEN BioMediaGREEN
-- Percent Clogged -- 100%
Excessive accumulation of sediment on tl-e BioMediaGREENJ media housed w thin the drain
down filter. The following photos show of the condition of the BioMediaGREEN contained
within the drain down fil:er. When media is more than 85% clogged replacemen: is required.
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Overgrown vegetation.
Water level in discharge chamber during 100% operating capacity (pre-treatment chamber
water level at max height) is lower than tFe watermark by 20%.
wwwniodularwetlandscom
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Inspection Notes
Following maintenance and/or inspection, it is recommended the maintenance operator
prepare a maintenance/inspection record. The record should include any maintenance
activities performed, amount and description of debris collected, and condition of the
system and its various filter mechanisms.
The owner should keep maintenance/inspection record(s) for a minimum of five years from
I the date of maintenarce. These records should be made available to the governing
municipality for inspection upon request at any time.
I
Transport all debris, trash, organics and sediments to approved facility for disposal in
accordance with local and state requirements.
Entry into chambers may require confined space training based on state and local
regulations.
No fertilizer shall be Lsed in the Biofiltration Chamber.
rrigation should be provided as -ecommended by manufactu-er and/or landscape
architect. Amount of irigation required is dependent on plant species. Some plants may
iot require irrigation after initial establishment.
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UloMedIaGREEN
r
Vert U' / 2 c
'
Flay, Co'tr r
E DIA 3 0~9(et Pipe
Cart
Maintenance Summary
Remove Sediment from Pre-Treatment Chamber - average maintenance interval is 12 to 24
months.
( 10 minute average service time).
Replace Pre-Filter Cartridge Media -average maintenance interval 12 to 24 months.
( 10- 15 mInute per cartridge average service time).
Trim Vegetation - average maintenance interval is 6 to 12 months.
(Service time varies)
System Diagram
Access to separation chamber
and pre-filter cartridge
Cw
Pre-treatment Chamber
Biofiltration Chamber
Discharge Chamber
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I Maintenance Overview
n www.modularwetlands.com
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The time has cone to maintain your Modular Wetland System Linear (MWS Linear). To eisure
sLccessfu and efficient maintenance on the system we recommend the o11ow1ng. The V1WS Linear
can be maintained by removing the access natches over the systems various chambers. A!l
necessary pre-maintenance steps must be carried out before maintenance occurs, espcially traffic
control and other safety measures to protect the inspector and near-by pedestrians from any dangers
associated with an open access hatch or manhole. Once traffic control has been set up per local and
state regulations and access covers have been safely opened the maintenance process can begin. It
should be roted that some maintenance activities require confined space entry. All con9ned space
requirements must be strictly followed before entry into the system. In addition the following is
recommended:
Prepare the maintenance form by witing in the necessary information including project name,
location, date & time, unit number and other info (see maintenance form).
Set up all appropriate safety and cleaning equipment.
Ensure traffic control is set up and properly positioned.
Prepare a pre-checks (OSHA, safety, confined space entry) are performed.
Maintenance Equipment
Following is a list of equipment required for maintenance of the MWS Linear:
Modular Wetland Maintenance Form
Manhole hook or appropriate tools to access hatches and covers
Protective clothing, flashlight and eye protection.
7/16" open or closed erded wrench.
Vacuum assisted truck with pressurE washer.
Replacement BioMediaGREEN for Pre-Filter Cartridges if required (order from man .jfacturer).
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Maintenance Steps
1. Pre-treatment Chamber (bottom of chamber)
Remove access hatch or manhole cover over pre-treatment chamber and position vacuum
truck accordingly.
With a pressure washer spray down pollutants accumulated on walls and pie-filter
cartridges.
Vacuum out Pre-Treatment Chamber and remove all accumulated pollutants including
trash, debris and sediments. Be sure to vacuum the floor until pervious payers are visible
and clean.
If Pre-Filter Cartridges require media replacement move onto step 2. If not, replace access
hatch or manhole cover.
Removal of access hatch to gain access below. Insertion of vacuum hose into separation hamber.
Fully cleaned separation chambe.
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:
Pre-filter cartridges with tops on.
Inside cartridges showing rredia filters ready for
replacement.
2. Pro-Filter Cartridges (attached to wall of pre-t-eatment chamber)
After finishing step 1 enter pre-treatment chamber.
Unscrew the two bol:s holding the lid on each cartridge filter and rerrove lid.
Place the vacuum hose over eac' individual media filter to suck out filter media.
Vacuuming out of media filters.
Once filter media has been sucked use a pressure washer to spray cown iiside of t'ie
cartridge and it's containing medi- cages Remove cleaned media cages and place to the
side. Once removed the vacuum hose can be inserted into the cartridge to vacuum out any
remaining material near the bottom or the cartridge.
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Refilling trey for media replacement.
Reinstall media cages and fill with new media from manufacturer or outside supplier.
Manufacturer will provide specification of media and sources to purchase. Utilize the
manufacture provided refilling trey and place on top of cartridge. Fill trey with new bulk
media and shake down into place. Using your hands slightly compact media into each filter
cage. Once cages are full removed refilling trey and replace cartridge top ensuring bolts
are properly tightened.
Exit pretreatment chamber. Replace access hatch or manhole cover.
3. Biofiltration Chamber (middle vegetated chamber)
A. In general, the biofiltration chamber is maintenance free with the exception of maintaining
the vegetation. Using standard gardening tools properly trim back the vegetation to healthy
levels. The MWS Linear utilizes vegetation similar to surrounding landscape areas
therefore trim vegetation to match surrounding vegetation. If any plants have died replace
plants with new ones: -.
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4. Discharge Chamber (contains drain down cartridge & connected to pipe)
Remove access hatch or manhole cover over discharge chamber.
Enter chamber to gain access to the drain down filter. Unlock the locking mechanism and
left up drain down filter housing to remove used BioMediaGREEN filter block as shown
below:
Insert new BioMedia3REEN filter block and lock drain down filter housing back in place.
Replace access hatch or manhole cover over discharge chamber.
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Inspection Notes
Following maintenance and/or inspection, it is recommended the maintenance operator
prepare a maintenance/inspection record. The record should include any mainterance
activities performed, amount and description of debris collected, and condition of the
system and its various filter mechanisms.
The owner should keep maintenance/inspection record(s) for a minimum of five years from
the date of maintenance. These records should be made available to The governing
municipality for inspection upon request at any time.
Transport all debris, trash, organics and sediments to approved facility for disposal in
accordance with local and state requirements.
Entry into chambers may require confined space training based on sta:e and local
regulations.
No fertilizer shall be used in the Biofiltration Chamber.
Irrigation should be provided as recommended by manufacturer and/or landscape
architect. Amount of irrigation required is dependent on plant species. Some plants may
not require irrigation after initial establishment.
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Inspection Form
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Modular Wetland System, Inc
P 760.433-7640
F 760-433-3176
E. Info@modularwetlands.com
www.modularwetiands.com
Inspection Report
+•• Modular Wetlands System r
Project Name
Project Address
(city) Zip code)
Owner / Management Company
Contact Phone ( ) -
Inspector Name Date ______! ______/ Time AM / PM
Type of Inspection 0 Routine LI Follow Up 0 Complaint 0 Storm Storm Event in Last 72-hours? 0 No 0 Yes
Weather Condition Additional Notes
Inspection Checklist
Modular Wetland System Type (Curb, Grate or UG Vault): Size (22, 14 or etc.):
Structural Integrity: Yes No Comments
Damage to pre-treatment access cover (manhole cover/grate) or cannot be opened using normal lifting
pressure?
Damage to discharge chamber access cover (manhole cover/grate) or cannot be opened using normal lifting
pressure?
Does the MWS unit show signs of structural deterioration (cracks in the wall, damage to frame)?
Is the inlet/outlet pipe or drain down pipe damaged or otherwise not functioning properly?
Working Condition:
Is there evidence of illicit discharge or excessive oil, grease, or other automobile fluids entering and clogging th
unit?
Is there standing water in inappropriate areas after a dry period?
Is the filter insert (if applicable) at capacity and/or is there an accumulation of debris/trash on the shelf system?
Does the depth of sediment/trash/debris suggest a blockage of the inflow pipe, bypass or cartridge filter? If yes
specify which one in the comments section. Note depth of accumulation in in pre-treatment chamber.
Does the cartridge filter media need replacement in pre-treatment chamber and/or discharge chamber? Chamber
Any signs of improper functioning in the discharge chamber? Note issues in comments section.
Other Inspection Items:
Is there an accumulation of sediment/trash/debris in the wetland media (if applicable)?
Is it evident that the plants are alive and healthy (if applicable)? Please note Plant Information below,
Is there a septic or foul odor coming from inside the system?
Waste: Yes No
Sediment! Silt I Clay
Trash / Bags / Bottles
Green Waste / Leaves / Foliage
Recommended Maintenance
No Cleaning Needed
Schedule Maintenance as Planned
Needs Immediate Maintenance
Plant Information
Damage to Plants
Plant Replacement
Plant Trimming
Additional Notes:
2972 San Luis Rey Road, Oceanside, CA 92058 P (760) 433-7640 F (760) 433-3176
Maintenance Report
E
Modular Wetland System, Inc.
P 760.433-7640
F. 760-433-3176
1 E. lnfo@modularwetlands.com
www.modularwetlands.com
CLEAN fl(C
Cleaning and Maintenance Report
Modular Wetlands System
Project Name
Project Address
Owner I Management Company
Contact
Inspector Name
Type of Inspection 0 Routine LI Follow Up LI Complaint
Weather Condition
Phone
Date /
0 Storm
Additional Notes
(ATJ(e Gv
(City) (Zip Cod
'e1 -
Time AM/PM
Storm Event in Last 72-hours? LI No LI Yes
Site
Map #
GPS Coordinates
of Insert
Manufacturer /
Description / Sizing
Trash
Accumulation
Foliage
Accumulation
Sediment
Accumulation
Total Debris
Accumulation
Condition of Media
25/50/75/100
(will be changed
@ 75%)
Operational Per
Manufactures'
Specifications
(If not, why?)
Lot: MWS
Catch Basins
Long:
MWS
Sedimentation
Basin
Media Filter
Condition
Plant Condition
Drain Down Media
Condition
Discharge Chamber
Condition
Drain Down Pipe
Condition
Inlet and Outlet
Pipe Condition -
Comments.
2972 San Luis Rey Road, Oceanside, CA 92058 P. 760433.7640 F. 760.433.3176
Under qro ur H stormwoter cetentiort crrrd infirno systems must
I uer PC, csd and MCI atone:: ci I f intervab ior purposes
nertormarice arrd loevhe.
Inspection
I uspectiort is the key toeffective Mai ntfenorive 0 CMP aete lion
systems and is easily perfonred. Canted' recommends, ogoir:,
armual inspections. Sites with high tash load or stall outlet
I control onfices may need more frequent pecteens. The rate
or "'which she system collecrs rrollutanrs will aepead more ran-
site sorscific ocees rather than the size or configuration of the
system.
should be perth-ed more often in equipment
wcshdown areas, in climates where sanding and/or salting
operations take place, and in other various instances if-, which
I one would expect h pher ocrmmutatioas of sediment or ahrasiva/
cam osive corrdihcrns. A macrd of is to be
oinioir:srdto rae Ideal tn system.
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V V VVVV eV -VVV VVVVVV'. :. V:V, VVVV55V K
V V VVV VVV •VV ,V,V:VVVVVVV :V V<V:V VII: V Vu s V 5.
r/VV VV,E,,VVVVVI,
VVuV,,Va VV fiVV) VV VVV 'a CVvIIIVVIV. V VV V I ) 3
;VV3VVVVVVV ,VVV:VVVVV;,;VIV:IVIV V 'V V VV V V V
VV IV VV V VV Vi 0 V CON VV:V35V VV VVVV V
CMPahstentiorr systems efrould be r:lrcmws :hen on 5a5pec3i05t -siveals
accumulated sediment or trash is cioqqiap she discharge C.C.
Accumulated sediment and rrasn can typcally no evncr.ared through
tie monhore over tie outset onfice, if moirrenance is not performed
as recommended, sediment and trash may oc:umulate in front of the
outlet orifice. Manhole covers should be s'ssutely seated foikrwng
cteanng ctivlties. >nteinh suggests that all systems he designed with
an ac.cess/insper:ton manhole situated at sr near the inlet and the
outlet orifice. Should it tie necessary to get inside tnr system to perform
nVramtenmuVrce ac.trvtiies, tl oporopriate precVarVrtrons regarding confined
space entry and OStIA regulations should ne followed.
Annual inspections are nest practice for alt unde'qraund systen-s.
Dr; ing this inspection it evidence of saltinaide-icna agents is observed
within the system, it is best practice tar the .aysVert to he rinsed,
including above the sar ng line soon after mEVV St5VV1n9 thaw as part at the
maintenance program for the system.
Maintuirring an urrderqrcurrd detention or nI trotior system is easiest
when there 5 no tlow enterrng the system, or this reason, it is a good
idea to schedule the cicanout during dry w-ea'he:
T he foregoing Inspection and mainlenancc ettorts nalp ensure
nUeiyrOuIia p;pa systems used lot sorrusroter storage continue to
function as intended by identifyirry recornir ended regular ;rrspecticrrr
and maintenance crocI ces. inspection and maintenance related to the
siruvtui al meqtty ut inc pipe or I tie soundness ml oce oirnt (Varnections
is beyond the scope of 'hs guide.
Vi.*I3V VtV
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CMP DETENTION SYSTEMS
CONTECH
ENGINSERED SOW(ONS
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Priority Development Project (PDP) SWQMP
BMW of Carlsbad
ATTACHMENT 4
City standard Single Sheet BMP (SSBMP) Exhibit
[Use the City's standard Single Sheet BMP Plan.]
C Commerda1
Rou,es
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PDP SWQMP 27 of 27
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CON ROAD :...• . . CDk fit
- Resources
40 SWMPNO. TED
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/ [.2A •....
. .. / . PARTY RESPONSIBLE FOR MA1NTENA1PCE:
'_.'• . <.< ç . E AU28ONA8C.
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CONTACT rA.IFFWrWFLs.
NAM
j- -- - - —
.----- .. . 1 rTT• I I ocss______RLY PLACE _______ I i 131 O8 DMA-IC J.74bAC NEWPORT BEACH .CA82NO
/ r 0 '320 AC PHONE NO 41S37 CERT78CATION AC P IJ
- —t. N --. . . . I 1 .8 l . . ESE PS SEEN 8541CR? TO BE INSTALLED PAIN MUNJFACOJREIFS
I RACOMMENCA ICNSO8NTAESPPLANS,
NO CHANGES TOTNC PROPOSED SMP ONTNSSINEBMOJOUTPRIOR
APPROVAL FROM THE CEHG8R.
3 NO SUBSTITUTIONS TO -.ME MATERIAL OR TYPES OR PLANTING ES
?STHOUT PRIORSFPROV#1. FROM THE CII? ENGINE—EA.
0 023 AC 4 NO OCCUPANCY PAIL BE GRANTED UNTIL TK CITY INSPECTION STAFF S / 1 HAS INSPECTED 148$ PROJECT FOR APPROPRIATE AMP CONSTRUCTION
/, rjl 1 ANDITSTALLNT'ON
' I 5 REFER TO MAINTENANCE AG REZMENT DOCUMENT
P SEE PROJEG '77W FOR ADDITIONAL INFORMATION. I . GE0TECHNICAL0TES:
HYDROLOWSO&GROURS
INFLTSSTIONIINAlR
SOIL (SF4851/A OTENIAL PER' LOW DMA -11E .- 3 O2.EONTOGROIJNSWAIEk'411
LL4±AC
.
>/(N3.J. it IL/X.j I
20 0 20 40
/ ______ 71 H A i GRAPHIC SCALE
L_ / SCALE: 1 20
4/.7
I
BMP TA
7 — BUFIDA NMFTYPE I SYMBOL LA&SA N04 OMANTITY [ DR
.11 HYDROMOD WCATN&TREATMENT CONTROL
82SF
Y i 1 8 - o X-9 SF
........+.........
..
7............................ .
.................
(1) WTNNp&H8A3 378SF 10-32 T (
CONTROL
TREATMENT
1am U[3__ "1 / () D
1 -/' , / - - HYDROMODIFICATION
I DMA gO / 'Z,.
/ ® SEEATION 4IcL/2 $ 31/N.
3 H 0.404AC LOW IMPACT DESIGN (1.LD.)
DMA 181 I 10423AC I
1?
I / 1 .76 ®3PERNE7AtSFS/ERS..L.4$OI/A2 15.7
$0115 78 '7
I C . ••__
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- ...... ......................................................
.... SIIEETH CITY OF CARlSBAD SHEETS
01 5NS8ER51/5 DEPARTMENT 01
srrs pxjs -
BMW OF CARLSBAD
I7A1A'UTIJCANIIIIlCOIIl-IT
. . (ALSlWi,CT32crW
IT.lIT/C-----II :::::4:3113. -RECORD COPY H PRCT -NO.
H: MS2019-OIiOi
~hui~~L PATE -INITIAL
REVISION DESCR1P110N OTHER CITY APPROVAL INITIAL DAIS TBD