HomeMy WebLinkAboutMS 2020-0004; ADAMS STREET HOMES; STORM WATER QUALITY MANAGEMENT PLAN; 2022-05-01CITY OF CARLSBAD
PRIORITY DEVELOPMENT PROJECT (PDP)
STORM WATER QUALITY MANAGEMENT PLAN (SWQMP)
FOR
ADAMS STREET HOMES
DWG 534-5A & 534-5
(MS 2020-0004 / CDP 2020-0043
GR 2021-0041 & ROW 2021-0889)
ENGINEER OF WORK:
_____________________________________________
TYLER G LAWSON, PE #80356
PREPARED FOR:
RREG INVESTMENTS SERIES, LLC SERIES I044
5315 AVENIDA ENCINAS, SUITE 200
CARLSBAD, CA 92008
PH: (888) 357-3553
PREPARED BY:
PASCO, LARET, SUITER & ASSOCIATES
1911 SAN DIEGO AVENUE, SUITE 100
SAN DIEGO, CA 92110
PH: (858) 259-8212
DATE:
MAY 2022
TABLE OF CONTENTS
Certification Page
Project Vicinity Map
FORM E-34 Storm Water Standard Questionnaire
Site Information
FORM E-36 Standard Project Requirement Checklist
Summary of PDP Structural BMPs
Attachment 1: Backup for PDP Pollutant Control BMPs
Attachment 1a: DMA Exhibit
Attachment 1b: Tabular Summary of DMAs and Design Capture Volume Calculations
Attachment 1c: Harvest and Use Feasibility Screening (when applicable)
Attachment 1d: Categorization of Infiltration Feasibility Condition (when applicable)
Attachment 1e: Pollutant Control BMP Design Worksheets / Calculations
Attachment 2: Backup for PDP Hydromodification Control Measures
Attachment 2a: Hydromodification Management Exhibit
Attachment 2b: Management of Critical Coarse Sediment Yield Areas
Attachment 2c: Geomorphic Assessment of Receiving Channels (Not Included)
Attachment 2d: Flow Control Facility Design
Attachment 3: Structural BMP Maintenance Thresholds and Actions
Attachment 4: Single Sheet BMP (SSBMP) Exhibit
CERTIFICATION PAGE
Project Name: ADAMS STREET HOMES / 3745 ADAMS STREET
Project ID: DWG 534-5A & 534-5 - (MS 2020-0004 / CDP 2020-0043)
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.
________________________________________________________
Engineer of Work's Signature, PE Number & Expiration Date
Tyler Lawson_____________________________________________
Print Name
Pasco, Laret, Suiter & Associates_____________________________
Company
____________________________
Date
PE 80356, Exp 12-31-22
5-5-2022
PROJECT VICINITY MAP
VICINITY MAP
SCALE:NTS
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, ‘STANDARD PROJECT’ with
TRASH CAPTURE 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 signed 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: APN:
ADDRESS:
The project is (check one): New Development Redevelopment
The total proposed disturbed area is: ft2 ( ) acres
The total proposed newly created and/or replaced impervious area is: ft2 ( ) acres
If your project is covered by an approved SWQMP as part of a larger development project, provide the project ID and the
SWQMP # of the larger development project:
Project ID SWQMP #:
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.
This Box for City Use Only
City Concurrence:
YES NO Date: Project ID:
By:
E-34 Page 1 of 4 REV 09/21
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
STORM WATER STANDARDS
QUESTIONNAIRE
E-34
Adams Street Homes
3745 Adams Street, Carlsbad, CA 92008
205-270-13-00
X
48,138 1.11 On site: 42,290 sf / ROW 5,848 sf
25,917 0.595 On site area: 20,050 sf (0.460 ac)
ROW area: 4,867 sf (0.112 ac)
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STEP 1
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
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 6, mark the 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:
a) Designed and constructed to direct storm water runoff to adjacent vegetated areas, or other non-
erodible permeable areas; OR
b) Designed and constructed to be hydraulically disconnected from paved streets or roads; OR
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
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?
If you answered “yes” to one or more of the above questions, provide discussion/justification below, then go to Step 6, 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.
X
X
X
X
The project proposes the street widening of Adams Street that will utilize Green Street design standards
including tree well BMP's to treat the new hardscape.
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* Environmentally Sensitive Areas include but are not limited to all Clean Water Act Section 303(d) impaired water bodies; 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.
STEP 3
TO BE COMPLETED FOR ALL NEW OR REDEVELOPMENT PROJECTS
To determine if your project is a PDP, please answer the following questions (MS4 Permit Provision E.3.b.(1)):
YES NO
1. 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, and public development projects on public or private land.
2. 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.
3. 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
refreshment stands selling prepared foods and drinks for immediate consumption (Standard Industrial
Classification (SIC) code 5812).
4. 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
development project includes development on any natural slope that is twenty-five percent or greater.
5. 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
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.
7. 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
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).*
8. 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.
9. 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 (ADT) of 100 or more vehicles per day.
10. 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?
11. 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%? (CMC
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 6, check the first box stating, “My project is a PDP …”
and complete applicant information.
If you answered “no” to all of the above questions, your project is a ‘STANDARD PROJECT’. Go to step 5, complete the
trash capture questions..
X
X
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X
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E-34 Page 4 of 4 REV 09/21
STEP 4
TO BE COMPLETED FOR REDEVELOPMENT PROJECTS THAT ARE PRIORITY DEVELOPMENT PROJECTS (PDP)
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) = sq. ft.
Total proposed newly created or replaced impervious area (B) = sq. ft.
Percent impervious area created or replaced (B/A)*100 = %
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 6, 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 6, check the first
box stating, “My project is a PDP …” and complete applicant information.
STEP 5
TO BE COMPLETED FOR STANDARD PROJECTS
Complete the question below regarding your Standard Project (SDRWQCB Order No. 2017-0077):
YES NO
Is the Standard Project within any of the following Priority Land Use (PLU) categories?
R-23 (15-23 du/ac), R-30 (23-30 du/ac), PI (Planned Industrial), CF (Community Facilities), GC (General
Commercial), L (Local Shopping Center), R (Regional Commercial), V-B (Village-Barrio), VC (Visitor
Commercial), O (Office), VC/OS (Visitor Commercial/Open Space), PI/O (Planned Industrial/Office), or
Public Transportation Station
If you answered “yes”, the ‘STANDARD PROJECT’ is subject to TRASH CAPTURE REQUIREMENTS. Go to step 6,
check the third box stating, “My project is a ‘STANDARD PROJECT’ subject to TRASH CAPTURE REQUIREMENTS
…” and complete applicant information.
If you answered “no”, your project is a ‘STANDARD PROJECT’. Go to step 6, check the second box stating, “My project is
a ‘STANDARD PROJECT’…” and complete applicant information.
STEP 6
CHECK THE APPROPRIATE BOX AND COMPLETE APPLICANT INFORMATION
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) per E-35 template for submittal at time of application.
My project is a ‘STANDARD PROJECT’ OR EXEMPT from PDP 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.
My project is a ‘STANDARD PROJECT’ subject to TRASH CAPTURE REQUIREMENTS and must comply with
TRASH CAPTURE REQUIREMENTS of the BMP Manual. I understand I must prepare a TRASH CAPTURE Storm
Water Quality Management Plan (SWQMP) per E-35A template for submittal at time of application.
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:
Kevin Dunn for: RREG
INVESTMENTS SERIES LLC Manager
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SITE INFORMATION CHECKLIST
Project Summary Information
Project Name ADAMS STREET HOMES
Project ID (MS 2020-0004 / CDP 2020-0043)
Project Address
3745 Adams Street
Carlsbad, CA 92008
Assessor's Parcel Number(s) (APN(s)) 205-270-13-00
Project Watershed (Hydrologic Unit) Carlsbad 904.31 (Agua Hedionda)
Parcel Area
_1.11___ Acres (__48,138___ Square Feet)
Existing Impervious Area
(subset of Parcel Area)
_0.031___ Acres (__ 1,330___ Square Feet)
Area to be disturbed by the project
(Project Area)
_1.11___ Acres (__48,138___ Square Feet)
Project Proposed Impervious Area
(subset of Project Area)
Adams Street Proposed Impervious Area
_0.460__ Acres (__20,050____ Square Feet)
_0.121__ Acres (__5,286____ Square Feet)
Project Proposed Pervious Area
(subset of Project Area)
Adams Street Proposed Pervious Area
_0.511__ Acres (__22,240____Square Feet)
_0.013__ Acres (__562____ Square Feet)
Note: Proposed Impervious Area + Proposed Pervious Area = Area to be Disturbed by the
Project.
This may be less than the Parcel Area.
Description of Existing Site Condition and Drainage Patterns
Current Status of the Site (select all that apply):
Existing development
Previously graded but not built out
Agricultural or other non-impervious use
✓ Vacant, undeveloped/natural
Description / Additional Information:
Existing Land Cover Includes (select all that apply):
✓ Vegetative Cover
✓ Non-Vegetated Pervious Areas
Impervious Areas
Description / Additional Information:
Underlying Soil belongs to Hydrologic Soil Group (select all that apply):
NRCS Type A
✓ NRCS Type B
NRCS Type C
NRCS Type D
Approximate Depth to Groundwater (GW):
GW Depth < 5 feet
✓ 5 feet < GW Depth < 10 feet
10 feet < GW Depth < 20 feet
GW Depth > 20 feet
Existing Natural Hydrologic Features (select all that apply):
Watercourses
Seeps
Springs
Wetlands
✓ None
Description / Additional Information:
Description of Existing Site Topography and Drainage
[How is storm water 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]:
(1) Existing drainage conveyance can be categorized as natural. There is not any significant
drainage infrastructure onsite to convey storm water, and most water travels through the site on
the surface by way of sheet flow. A portion of the site drains to a local low point towards the
middle of the site, where it can be assumed ponding occurs. Water eventually leaves the site to
the west towards the western property line. Runoff will continue to sheet flow across the extent
of the western boundary. Just offsite on the property to the west exists a wall that partly retains
and is majority freestanding. In a rain event, drainage appears to eventually make its way
through the wall by means of weepholes or local low spots to continue west through the
adjacent property towards Pio Pico. Once in Pio Pico, runoff enters an existing storm drain curb
inlet in front of the New Song Church and is conveyed toward the outlet in the Agua Hedionda
Lagoon a buried pipe network.
(2) There are not any existing onsite storm water conveyance systems. Water eventually leaves
the subject property at the western property line. Drainage leaving the site flows on the surface
and continues in a westerly direction.
(3) Portions of the Adams Street right-of-way will discharge onto the project site. Adams Street
consist of partially landscaped and paved areas. The majority of the offsite runoff will come
from a landscaped strip adjacent to the eastern property line consisting of low shrubs and
mature palm trees.
Description of Proposed Site Development and Drainage Patterns
Project Description / Proposed Land Use and/or Activities:
The project proposes to demolish all existing onsite structures, clear and grub the site, and
construct 4 new single-family homes with additional dwelling units along with other hardscape
and landscape improvements typical of single-family development. The project also proposes
the street widening of Adams Street with various hardscape and landscape improvements.
List/describe proposed impervious features of the project (e.g., buildings, roadways, parking
lots, courtyards, athletic courts, other impervious features):
Proposed impervious features onsite include buildings / roof areas, concrete walkways,
driveways, and drive aisles.
List/describe proposed pervious features of the project (e.g., landscape areas):
Proposed pervious features onsite include landscaping and biofiltration treatment control BMPs.
Does the project include grading and changes to site topography?
✓ Yes
No
Description / Additional Information:
Project proposes to precise grade the site along with some changes to onsite topography. The
onsite grading consists of approximately 45 CY of cut and 6,350 CY of fill, resulting in 6,255 CY
of import. The proposed drainage system has been designed to flow from east to west into a
biofiltration basin with partial retention for treatment control and detention.
Does the project include changes to site drainage (e.g., installation of new storm water
conveyance systems)?
✓ Yes
No
Description / Additional Information:
Although the project proposes onsite grading, the drainage patterns after precise grading mimic
pre-development patterns. The site will continue to drain from east to west, and discharge
along the western property line. In pre-development condition runoff sheet flows across the lot
from east to west. In the post-development condition new drainage infrastructure will be
installed to direct drainage toward a biofiltration basin near the western property line. Trench
drains, catch basins, and storm drain pipes will be used to manage storm water flows.
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
Interior floor drains and elevator shaft sump pumps
Interior parking garages
Need for future indoor & structural pest control
✓ Landscape/Outdoor Pesticide Use
Pools, spas, ponds, decorative fountains, and other water features
Food service
Refuse areas
Industrial processes
Outdoor storage of equipment or materials
Vehicle and Equipment Cleaning
Vehicle/Equipment Repair and Maintenance
Fuel Dispensing Areas
Loading Docks
Fire Sprinkler Test Water
Miscellaneous Drain or Wash Water
✓Plazas, sidewalks, and parking lots
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):
Drainage leaving the site appears to eventually make its way through the wall by means of
weepholes or local low spots to continue west through the adjacent property towards Pio Pico.
Once in Pio Pico, runoff enters an existing storm drain curb inlet in front of the New Song
Church and is conveyed toward the outlet in the Agua Hedionda Lagoon via the City’s buried
pipe network.
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
Buena Vista Lagoon Indicator Bacteria
Nutrients
Sedimentation / Siltation
Toxicity
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):
Pollutant
Not Applicable to
the Project Site
Anticipated from the
Project Site
Also a Receiving
Water Pollutant of
Concern
Sediment X
Nutrients X
Heavy Metals
Organic Compounds
Trash & Debris X
Oxygen Demanding
Substances X
Oil & Grease X
Bacteria & Viruses X
Pesticides X
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.
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.
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.
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):
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?
Yes
✓ 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?
6.2.1 Verification of Geomorphic Landscape Units (GLUs) Onsite
6.2.2 Downstream Systems Sensitivity to Coarse Sediment
6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite
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?
No critical coarse sediment yield areas to be protected based on verification of GLUs onsite
Critical coarse sediment yield areas exist but additional analysis has determined that
protection is not required. Documentation attached in Attachment 8 of the SWQMP.
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:
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.
The project has a single POC, which is identified as “POC-1” on the HMP Exhibit of this report.
POC-1 is located at the outlet of the biofiltration basin adjacent to the western property line.
Has a geomorphic assessment been performed for the receiving channel(s)?
✓ No, the low flow threshold is 0.1Q2 (default low flow threshold)
Yes, the result is the low flow threshold is 0.1Q2
Yes, the result is the low flow threshold is 0.3Q2
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)
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.
Constraints that influenced storm water management design included site grading to allow
drainage to resemble existing drainage patterns. Additionally, drainage in the existing condition
included runon from the adjacent Adams Street right-of-way. To prevent that storm water from
Adams Street to enter the site in the proposed condition a PCC curb and gutter is being
included to the site design. The curb and gutter will direct storm water to a tree well to mitigate
the drainage produced from offsite hardscape.
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.
E-36 Page 1 of 3 Revised 09/21
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
STANDARD PROJECT
REQUIREMENT
CHECKLIST
E-36
Project Information
Project Name:
Project ID:
DWG No. or Building Permit No.:
Baseline BMPs for Existing and Proposed Site Features
Complete the Table 1 - Site Design Requirement to document existing and proposed site features and the BMPs to be
implemented for them. All BMPs must be implemented where applicable and feasible. Applicability is generally
assumed if a feature exists or is proposed.
BMPs must be implemented for site design features where feasible. Leaving the box for a BMP unchecked means it
will not be implemented (either partially or fully) either because it is inapplicable or infeasible. Explanations must be
provided in the area below. The table provides specific instructions on when explanations are required.
Table 1 - Site Design Requirement
A. Existing Natural Site Features (see Fact Sheet BL-1)
1. Check the boxes below for each existing feature on
the site.
1. Select the BMPs to be implemented for each identified feature. Explain
why any BMP not selected is infeasible in the area below.
SD-G
Conserve natural
features
SD-H
Provide buffers around waterbodies
Natural waterbodies
Natural storage reservoirs & drainage corridors --
Natural areas, soils, & vegetation (incl. trees) --
B. BMPs for Common Impervious Outdoor Site Features (see Fact Sheet BL-2)
1. Check the boxes below for each
proposed feature.
2. Select the BMPs to be implemented for each proposed feature. If neither BMP SD-B nor
SD-I is selected for a feature, explain why both BMPs are infeasible in the area below.
SD-B
Direct runoff to pervious
areas
SD-I
Construct surfaces from
permeable materials
Minimize size of
impervious areas
Streets and roads Check this box to confirm
that all impervious areas on
the site will be minimized
where feasible.
If this box is not checked,
identify the surfaces that
cannot be minimized in area
below, and explain why it is
infeasible to do so.
Sidewalks & walkways
Parking areas & lots
Driveways
Patios, decks, & courtyards
Hardcourt recreation areas
Other: _______________
C. BMPs for Rooftop Areas: Check this box if rooftop areas are proposed and select at least one BMP
below.
If no BMPs are selected, explain why they are infeasible in the area below.
(see Fact
Sheet BL-3)
SD-B
Direct runoff to pervious areas
SD-C
Install green roofs
SD-E
Install rain barrels
Adams Street Homes
x
x
xx
x
x x
x
x
534-5A
MS 2020-0004 / CDP 2020-0043
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C cityof
Carlsbad
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E-36 Page 2 of 3 Revised 09/21
D. BMPs for Landscaped Areas: Check this box if landscaping is proposed and select the BMP below
SD-K Sustainable Landscaping
If SD-K is not selected, explain why it is infeasible in the area below.
(see Fact
Sheet BL-4)
Provide discussion/justification for site design BMPs that will not be implemented (either partially or fully):
Baseline BMPs for Pollutant-generating Sources
All development projects must complete Table 2 - Source Control Requirement to identify applicable requirements for
documenting pollutant-generating sources/ features and source control BMPs.
BMPs must be implemented for source control features where feasible. Leaving the box for a BMP unchecked means it
will not be implemented (either partially or fully) either because it is inapplicable or infeasible. Explanations must be
provided in the area below. The table provides specific instructions on when explanations are required.
Table 2 - Source Control Requirement
A. Management of Storm Water Discharges
1. Identify all proposed outdoor
work areas below
Check here if none are proposed
2. Which BMPs will be used to prevent
materials from contacting rainfall or
runoff?
(See Fact Sheet BL-5)
Select all feasible BMPs for each work area
3. Where will runoff from the
work area be routed?
(See Fact Sheet BL-6)
Select one or more option for each
work area
SC-A
Overhead
covering
SC-B
Separation
flows from
adjacent
areas
SC-C
Wind
protection
SC-D
Sanitary
sewer
SC-E
Containment
system
Other
Trash & Refuse Storage
Materials & Equipment Storage
Loading & Unloading
Fueling
Maintenance & Repair
Vehicle & Equipment Cleaning
Other: _________________
B. Management of Storm Water Discharges (see Fact Sheet BL-7)
Select one option for each feature below:
• Storm drain inlets and catch basins … are not proposed
will be labeled with stenciling or signage to
discourage dumping (SC-F)
• Interior work surfaces, floor drains &
sumps …
are not proposed
will not discharge directly or indirectly to the MS4
or receiving waters
• Drain lines (e.g. air conditioning, boiler,
etc.) …
are not proposed
will not discharge directly or indirectly to the MS4
or receiving waters
• Fire sprinkler test water … are not proposed will not discharge directly or indirectly to the MS4
or receiving waters
Provide discussion/justification for source control BMPs that will not be implemented (either partially or fully):
x
x
x
x
x
x
x
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□
□ □ □ □ □ □ □
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E-36 Page 3 of 3 Revised 09/21
Form Certification
This E-36 Form is intended to comply with applicable requirements of the city’s BMP Design Manual. I certify that it has
been completed to the best of my ability and accurately reflects the project being proposed and the applicable BMPs
proposed to minimize the potentially negative impacts of this project's land development activities on water quality. I
understand and acknowledge that the review of this form by City staff is confined to a review and does not relieve me as
the person in charge of overseeing the selection and design of storm water BMPs for this project, of my responsibilities for
project design.
Preparer Signature: Date:
Print preparer name:
Bryan Knapp
10/18/21~--::::;.,.,,-I , ,,,,,_....
SUMMARY OF PDP STRUCTURAL BMPS
PDP Structural BMPs
All PDPs must implement structural BMPs for storm water pollutant control (see Chapter 5 of
the BMP Design Manual). Selection of PDP 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 Chapter 6 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).
PDP structural BMPs must be verified by the City at the completion of construction. This may
include requiring the project owner or project owner's representative to certify construction of
the structural BMPs (see Section 1.12 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 PDP 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.
After development of the project site plan (including size of proposed structures) in accordance
with City of Carlsbad General Plan and local zoning ordinance, the structural BMP deemed
most feasible for the site was a biofiltration basin with partial infiltration; refer to GEI supplement
letter dated March 30, 2022 for discussion on applicability of partial infiltration based on field
observed infiltration testing despite restricted infiltration category based on revised. Evaluation
of harvest and reuse was completed in accordance with the City of Carlsbad’s I-7 Form –
Feasibility Checklist and was deemed to be infeasible. The project proposes two biofiltration
basins to be located onsite. Biofiltration basin BMP-1 will be constructed between parcels 3 and
4 at a surface elevation of 85.5 and surface area of 700 sf. The majority of parcels 2, 3, and 4
will drain into biofiltration basin BMP-1 with storm water to be conveyed through a series of
trench drains, area drains, and PVC drain-pipes. Biofiltration basin BMP-2 will be constructed in
the southeastern portion of parcel 3 at a surface elevation of 86.0 and surface area of 275 sf.
Parcel 1 and portions of parcel 3 will drain into BMP-2 also by way of trench drain, area drains,
and PVC drain-pipes. The site will continue to drain from east to west with parcels 1 and 2 at
higher pad elevations than parcels 3 and 4 with all draining via gravity flow to the basins.
The biofiltration basins will be constructed almost identically and will include a 36” x 36” brooks
box outlet structure to further facilitate the conveyance of mitigated water and flows from large
storm events. BMP-1 will have 18” of ponding from the basin surface to the grate inlet at the top
of the brooks box, while BMP-2 will have 12” of ponding. Both basins will have an 18” layer of
engineered soil and 18” Permavoid layer beneath. The brooks box of BMP-1 will outlet water
into an 8” PVC perforated drain-pipe that will discharge water evenly along the entire western
property line, similar to the pre-development condition. The brooks box of BMP-2 will outlet
water into an 8” PVC drain-pipe that will connect to a PCC brow ditch constructed along the
southern property line and direct water to the western property edge.
To treat the proposed hardscape improvements in the Adams Street right-of-way, 2 x 10’
diameter tree wells (with 4’ wide x 10’ long x 4’ deep column of structural soil) are proposed in
the parkway with curb cuts to receive surface drainage from Adams Street. The amount of
structural soil provided has been designed per fact sheet SD-A. The tree wells have been
designed to treat the hardscape proposed in each area and manage pollutant control in
accordance with the USEPA Green Street Guidance. The tree well design conforms with the
County of San Diego Green Street Design using modified GS-1.04a & GS-1.04b details as
shown on the City of Carlsbad DWG 534-5 improvement plans for Adams Street widening.
Additional landscaped area has been proposed around the tree wells to allow for impervious
area dispersion of the non-continuous sidewalk, minimizing the impervious area impact in the
right of way.
Structural BMP Summary Information
[Copy this page as needed to provide information for each individual proposed
structural BMP]
Structural BMP ID No. BMP-1 (PR-1)
DWG MS-2020-0004 Sheet No. 2-3
Type of structural BMP:
Retention by harvest and use (HU-1)
Retention by infiltration basin (INF-1)
Retention by bioretention (INF-2)
Retention by permeable pavement (INF-3)
✓ Partial retention by biofiltration with partial retention (PR-1)
Biofiltration (BF-1)
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
Other (describe in discussion section below)
Purpose:
Pollutant control only
Hydromodification control only
✓ Combined pollutant control and hydromodification control
Pre-treatment/forebay for another structural BMP
Other (describe in discussion section below)
Discussion (as needed):
700 SF bioretention basin located in between parcels 3 and 4 with a finished surface elevation
of 85.5. Refer to project DMA Exhibit for size of drainage area tributary to basin and cross-
section of BMP. Emergency overflow structure included in BMP for higher intensity storm
events to convey water offsite also provided.
Structural BMP Summary Information
[Copy this page as needed to provide information for each individual proposed
structural BMP]
Structural BMP ID No. BMP-2 (PR-1)
DWG MS-2020-0004 Sheet No. 2-3
Type of structural BMP:
Retention by harvest and use (HU-1)
Retention by infiltration basin (INF-1)
Retention by bioretention (INF-2)
Retention by permeable pavement (INF-3)
✓ Partial retention by biofiltration with partial retention (PR-1)
Biofiltration (BF-1)
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
Other (describe in discussion section below)
Purpose:
Pollutant control only
Hydromodification control only
✓ Combined pollutant control and hydromodification control
Pre-treatment/forebay for another structural BMP
Other (describe in discussion section below)
Discussion (as needed):
275 SF bioretention basin located in the front yard of parcel 3 with a finished surface elevation
of 86.0. Refer to project DMA Exhibit for size of drainage area tributary to basin and cross-
section of BMP. Emergency overflow structure included in BMP for higher intensity storm
events to convey water offsite also provided.
ATTACHMENT 1
BACKUP FOR PDP POLLUTANT CONTROL BMPS
This is the cover sheet for Attachment 1. Check which Items are Included behind this cover sheet: Attachment Sequence Contents Checklist
Attachment 1a DMA Exhibit (Required) See DMA Exhibit Checklist on the back of this Attachment cover sheet. (24”x36” Exhibit
typically required)
Included
Attachment 1b Tabular Summary of DMAs Showing DMA ID matching DMA Exhibit, DMA Area, and DMA Type (Required)* *Provide table in this Attachment OR on DMA Exhibit in Attachment 1a
Included on DMA Exhibit in Attachment 1a
Included as Attachment 1b,
separate from DMA Exhibit Attachment 1c Form K-7, Harvest and Use Feasibility Screening Checklist (Required unless the entire project will
use infiltration BMPs) Refer to Appendix B of the BMP Design Manual
to complete Form K-7.
Included
Not included because the entire project will use infiltration BMPs
Attachment 1d Infiltration Feasibility Analysis (Required unless the project will use harvest and use BMPs)
Refer to Appendix D of the BMP Design Manual.
Included
Not included because
the entire project will use harvest and use BMPs
Attachment 1e Pollutant Control BMP Design Worksheets /
Calculations (Required) Refer to Appendices B, E, and I of the BMP
Design Manual for structural pollutant control and significant site design BMP design guidelines
Included
Attachment 1f Trash Capture BMP Design Calculations (Required unless the entire project will use
permanent storm water quality basins) Refer to Appendices J of the BMP Design Manual
for Trash capture BMP design guidelines
Included
Not included because the entire project will use permanent storm water quality basins (i.e. infiltration, biofiltration BMPs)
X
X
X
X
X
X
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
(N/A) Existing natural hydrologic features (watercourses, seeps, springs, wetlands)
(N/A) 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)
XXXXXXXXXXXXXXXXXXXXXXXXS
92 9292 929292
92 929
291
91
9
1
91
91
91 9191919190
9
090
90
90 90909090
898989898989
89
89 898989
8888
888888
88 888888
8888
8787 87
87
878787
87
878
7
87
8786
86
86 86
8686868
686
8686
86
8685
85
85
85
85 85
8585858585
858
5
858484
84 84
84
84
8484
84848484
84
84
83 83
83
8
383 8383838383
82
82
828
2 82828
2
8
2
8282
818181818181818
1
8080
X
X XXXXXXXXXXXXDENSE OVERGROWTHREQUIRES CLEARINGFOR A MORE
ACCURATE SURFACE
DENSE OVERGROWTHREQUIRES CLEARINGFOR A MORE
ACCURATE SURFACE
SHIPPINGCONTAINER ADAMS STREETAPN:
205-270-43-00
APN:
205-270-24-00
APN:
205-270-27-00
APN:
205-270-12-00
/
/
/////////////////////////XXXXXXXXXXXX X X X XXXXXXXXXXXXXXXXXXXXXX X X X X X X X X X X X XX X
XXXX84
85 86 87
83 88
89909188
89
90
87
86848583
828182929192918990889291
929290
90
SDSDSDSDSDS
D
SDSDSDSDSDSDSDSDSDSDSDSD
1A
1A
1A
1A
2A
2A
1A
1A
1B
2B
1B
1B
1B
1B
1D
1D
1D
1D
1D
2D
2D
1C
1C
1C
1C
2C
1C
1E
1E
1E
2E
1E
2E
1E
BMP-1 DMA 1
AREA= 28,465 SF
= 0.653 AC
BMP
OUTLET;
82.5 IE
FLOW SPREADER
DEVICE AND
RIP RAP
DMA 5:SELF-MITIGATINGDMA AREA PERSECTION 5.2.1 OF
BMP DESIGN MANUAL
DMA 5:
SELF-MITIGATING
DMA AREA PER
SECTION 5.2.1 OF
BMP DESIGN MANUAL DMA 5
AREA = 4,270 SF
= 0.098 AC
FG = 85.5
(81.5 IE OUT)
DMA 2
AREA= 9,555 SF
= 0.219 AC
2E
BMP-2
FG = 86.0
2A
1D
1D
1D
2D
2D SEE SHEET 2 FORDWG 534-5APPROX. ROOF
RIDGELINE
(TYP.)
DOWNSPOUT
(TYP.)
FG = 85.5
3:13:1
36" X 36" BROOKS
BOX; 87.0 TG
6" FREEBOARD
AND CONVEYANCE
ABOVE RISER PLANT MIX PER
LANDSCAPEARCHITECT PLAN18" PONDINGDEPTH
87.5 TOP
OF SLOPE 87.5 TOP
OF SLOPE
ORIFICE PLATEPER DETAILSHEET 5, DRILLEDTO INSIDE OF BOX
2:1 2:124"XXXXFENCING PER
LANDSCAPE PLANS
PROPOSED DEEPENED
EDGE AT WALKWAY; SEE
DETAIL SHEET 5
18" ENGINEERED SOILLAYER; *SEE NOTE
BELOW
18" LAYER PERMAVOID SYSTEM (3
X PV150 MODULE W/ 95% VOID
RATIO) OR APPROVED EQUAL
82.25 BOTTOM OF BASIN
ELEVATION; PERMEABLEGEOTEXTILE FABRIC TOWRAP PERMAVOID SYSTEM
PERMEABLE GEOTEXTILE
FABRIC LAYER (MIRAFI 1100N
OR EQUAL) BETWEEN PEA
GRAVEL LAYER AND
PERMAVOID SYSTEM
3" LAYER OF 3/8"
PEA GRAVEL
8" PVC EMERGENCY
OVERFLOW OUTLET
DRAIN PIPE; 82.5 IE
OUT0.5" HMP-SIZEDLOW-FLOW ORIFICE, DRILLEDINTO ORIFICE PLATE; 82.5 IE
6" PVC OUTLET PIPE FROM
PERMAVOID MODULE SYSTEM
TO CONNECT TO OUTLET
STRUCTURE W/ ORIFICE
PLATE
FENCING PER
LANDSCAPE PLANS
PROPOSED DEEPENED
EDGE AT WALKWAY; SEE
DETAIL SHEET 5
~1'-1.5' MAX ENGINEERED FILL MATERIALBETWEEN BASIN BOTTOM AND NATIVEMATERIAL SELECTIVELY GRADED PER
GEOTECH RECOMMENDATION TO
PROVIDE RELIABLE INFILTRATION
PROPERTIES
EXISTING GRADE
PERMEABLE GEOTEXTILE FABRICLAYER (MIRAFI 1100N OR EQUAL)BETWEEN PEA GRAVEL LAYERAND PERMAVOID SYSTEM
IMPERMEABLE
LINER (MIRAFI
30-MIL140N OR
APPROVED EQUAL)
ALONG SIDES OF
BMP ONLY
87.03'100-YR WSEL
FG = 86.0
3:13:1
18" ENGINEERED SOIL
LAYER; *SEE NOTE
BELOW
18" LAYER PERMAVOID SYSTEM
(3 X PV150 MODULE W/ 95%
VOID RATIO) OR APPROVEDEQUAL82.75 BOTTOM OF BASINELEVATION; PERMEABLE
GEOTEXTILE FABRIC TO
WRAP PERMAVOID SYSTEM
36" X 36" BROOKS
BOX; 87.0 TG
6" FREEBOARDAND CONVEYANCEABOVE RISER
PLANT MIX PER
LANDSCAPE
ARCHITECT PLAN
1.0% - 2.0%1.0% - 2.0%
12" PONDINGDEPTHFG = 87.5
PERMEABLE GEOTEXTILE FABRIC
LAYER (MIRAFI 1100N OR EQUAL)BETWEEN PEA GRAVEL LAYERAND PERMAVOID SYSTEM
FG = 87.5
IMPERMEABLE
LINER (MIRAFI
30-MIL 140N OR
APPROVED EQUAL)
ALONG SIDES OFBMP ONLY
3" LAYER OF 3/8"PEA GRAVEL
2:1 2:1
0.4" HMP-SIZED
LOW-FLOW ORIFICE, DRILLED
INTO ORIFICE PLATE; 83.0 IE
ORIFICE PLATE
PER DETAIL
SHEET 5, DRILLED
TO INSIDE OF BOX
6" PVC EMERGENCY
OVERFLOW OUTLET
DRAIN PIPE; 83.0 IE
OUT
6" PVC OUTLET PIPE FROMPERMAVOID MODULE SYSTEM
TO CONNECT TO OUTLET
STRUCTURE W/ ORIFICE
PLATE24"~1'-1.5' MAX ENGINEERED FILL MATERIAL
BETWEEN BASIN BOTTOM AND NATIVEMATERIAL SELECTIVELY GRADED PERGEOTECH RECOMMENDATION TOPROVIDE RELIABLE INFILTRATION
PROPERTIES
EXISTING GRADE
86.7'
100-YR WSEL
EXTEND LINER BELOW NATIVE
SOIL 2' MIN.
*BIOFILTRATION "ENGINEERED SOIL"
LAYER SHALL BE MINIMUM 18" DEEPPER CITY OF CARLSBAD BMPM A N U A L A P P E N D I X F . 3 -BIORETENTION SOIL MEDIA (BSM)
S P E C I F I C A T I O N
*BIOFILTRATION "ENGINEERED SOIL"
LAYER SHALL BE MINIMUM 18" DEEP
PER CITY OF CARLSBAD BMPM A N U A L A P P E N D I X F . 3 -BIORETENTION SOIL MEDIA (BSM)S P E C I F I C A T I O N
PLSA 3339-01
PLAN VIEW - DMA EXHIBIT
SCALE: 1" = 20' HORIZONTAL
20 40 60
GRAPHIC SCALE: 1" = 20'
020
SOIL TYPE INFORMATION
SOIL: TYPE B HYDROLOGIC SOILS PER WEB SOIL SURVEY
APPLICATION AVAILABLE THROUGH UNITED STATES DEPARTMENT OF
AGRICULTURE
GROUNDWATER INFORMATION
GROUNDWATER ENCOUNTERED AT DEPTHS FROM 5 TO 10 FEET
TREATMENT CONTROL BMPS
BIOFILTRATION W/ PARTIAL RETENTION PR-1
COARSE SEDIMENT YIELD
NO CRITICAL COARSE SEDIMENT YIELD AREAS TO BE
PROTECTED. REFER TO PRIORITY DEVELOPMENT PROJECT
SWQMP PREPARED BY PASCO, LARET, SUITER & ASSOCIATES
LEGEND
PROPERTY BOUNDARY
CENTERLINE OF ROAD
RIGHT-OF-WAY
ADJACENT PROPERTY LINE
EXISTING CONTOUR LINE
PROPOSED CONTOUR LINE
DMA DRAINAGE BASIN BOUNDARY
PROPOSED / REMOVED AND REPLACEDIMPERVIOUS AREA WITHIN DISTURBEDAREA OF SITE
BMP / BIOFILTRATION BASIN AREA
SELF-MITIGATING AREA
DMA EXHIBIT - ATTACHMENT 1A_B
3745 ADAMS STREET
CITY OF CARLSBAD
256
256
SHEET 1 OF 2
TOTAL GROSS SITE AREA 42,290 SF (0.971 AC)
EXISTING IMPERVIOUS AREA 0 SF (0.000 AC)EXISTING PERVIOUS AREA 42,290 SF (0.971 AC)
TOTAL AREA DISTURBED BY PROJECT (ONSITE)42,290 SF (0.971 AC)TOTAL PROPOSED / REPLACED IMPERVIOUS AREA (ONSITE) 20,050 SF (0.460 AC)
DRAINAGE MANAGEMENT AREA EXHIBIT
ADAMS RESIDENCES
DCV CALCULATION - DMA 2 - BMP 2
AREA TRIBUTARY TO BMP (A)= 9,555 SF (0.219 AC)
TOTAL DMA SIZE (Cx * Ax)= 4,576 SF
RUNOFF FACTOR (Cx)= 0.4885TH PERCENTILE RAINFALL DEPTH (d) = 0.60 IN
DCV (C*D*A*3,630)= 229 CU FT
TOTAL DMA SIZE = 4,576 SF
IMP. SIZING FACTOR = 0.03 (FOR BIOFILTRATION BMPS)
MIN. AREA REQUIRED = 0.03 * 4,576 SF = 137 SF
275 SF PROVIDED > 137 SF REQUIRED; THEREFORE OK
IMPERVIOUS AREA (BUILDINGS / ROOF)2,630 SF
(MISC IMPROVEMENTS)1,895 SF
TOTAL 4,525 SF
PERVIOUS AREA (LANDSCAPING)4,755 SF
(BIORETENTION BASIN)275 SFTOTAL5,030 SF
TOTAL BASIN AREA 9,555 SF
% IMPERVIOUS AREA 47.4%
J:\ACTIVE JOBS\3339 3745 ADAMS STREET\CIVIL\REPORTS\SWQMP\Final Engineering\Attachments\Attachment 1 - Pollutant Control\Att_1a-b - DMA.dwg
TYPICAL DETAIL - BMP-1 BIOFILTRATION BASIN
NOT TO SCALE
SELF-MITIGATING DMA - DMA 5
TOTAL BASIN SIZE = 4,270 SF (0.098 AC)
SELF-MITIGATING IMPERVIOUS AREA = 134 SF% IMPERVIOUS = 4.9%
SECTION 5.2.1 OF THE CITY OF CARLSBAD BMP DESIGN MANUAL ALLOWS FOR
SELF-MITIGATING DMA AREAS THAT DRAIN DIRECTLY OFFSITE OR TO THE PUBLIC STORM
DRAIN SYSTEM, WITH INCIDENTAL IMPERVIOUS AREAS THAT ARE LESS THAN 5% OF THE
SELF-MITIGATING AREA
DCV CALCULATION - DMA 1 - BMP 1
AREA TRIBUTARY TO BMP (A)= 28,465 SF (0.653 AC)
TOTAL DMA SIZE (Cx * Ax)= 15,267 SF
RUNOFF FACTOR (Cx)= 0.54
85TH PERCENTILE RAINFALL DEPTH (d) = 0.60 IN
DCV (C*D*A*3,630)= 769 CU FT
TOTAL DMA SIZE = 15,267 SF
IMP. SIZING FACTOR = 0.03 (FOR BIOFILTRATION BMPS)MIN. AREA REQUIRED = 0.03 * 15,267 SF = 458 SF
700 SF PROVIDED > 458 SF REQUIRED; THEREFORE OK
IMPERVIOUS AREA (BUILDINGS / ROOF)7,365 SF(MISC IMPROVEMENTS)8,160 SF
TOTAL 15,525 SF
PERVIOUS AREA (LANDSCAPING)12,240 SF
(BIORETENTION BASIN)700 SF
TOTAL 12,940 SF
TOTAL BASIN AREA 28,465 SF
% IMPERVIOUS AREA 54.5%
TYPICAL DETAIL - BMP-2 BIOFILTRATION BASIN
NOT TO SCALE
DMA 1 - AREA CALCULATIONS
DMA 2 - AREA CALCULATIONS
PROJECT SITE - AREA CALCULATIONS
PROJECT SITE - TOTAL AREADMAAREABMP
TOTAL ON SITE AREA
1 28,465 SF 1252-9,555 SF4,270 SF 42,290 SF
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BMP
A
B
C
D
E
1
TOTAL
OMA TABLE-TREATMENT(DMA 1)
AREAX SURFACE ADJUSTMENT ADJUSTED AREA POST-PROJECT RUNOFF FA CTOR RUNOFF (SF) SURFACE TYPE FACTOR (SF)
7365 ROOF 0.9 1 6629
1306 PRK HARDSCAPE 0.9 1 1175
5875 DRIVING HARDSCAPE 0.9 1 5288
979 PCC WALKWAYS 0 9 1 881
12240 LANDSCAPE 0.1 1 1224
700 BMP 0.1 1 70
15267
_J
OMA /
BMP
A
B
C
D
E
2
TOTAL
AREA
(SF)
2630
303
1364
227
4755
275
--
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+++++++++ ++++++++!!+++++++++ ++++++++
[,,>>>>>>>>>>>>>)
OMA TABLE -TREATMENT (OMA 2)
AREAX SURFACE ADJUSTMENT ADJUSTED POST-PROJECT RUNOFF FACTOR RUNOFF (SF) SURFACE TYPE FACTOR
ROOF 0.9 1 2367
PRK HARDSCAPE 0.9 1 273
DRIVING HARDSCAPE 0.9 1 1228
PCC WALKWAYS 0.9 1 205
LANDSCAPE 0.1 1 476
BMP 0.1 1 28
4576
PASCO LAREl~!~~ii,H
. I Solana Beach I Orange County
San Diego 8212 1 www.plsaengineering.com Phone 858.259.
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///////////////////////////SDSDSDSDS
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SDSDSDSDSDSDSDSD
TREE WELL
W/O GRATE
PER DETAIL
DMA EXHIBITADAMS STREETTREE WELL
W/O GRATE
PER DETAIL
DMA EXHIBIT
DMA 3
AREA = 1,187 SF
(0.03 AC)
DMA 4
AREA = 1,331 SF
(0.03 AC)
IMPERVIOUS
AREA
DISPERSION
IMPERVIOUS
AREA
DISPERSION
PCC CURB &GUTTER (SIZE
PER PLAN)
PCC CURB &
GUTTER (SIZEPER PLAN)
CONSTRUCT PCC
SIDEWALK PER PLAN
B B
A
A
18" WIDE CURB CUTCENTERED ON TREEWELL (SEE DETAILB-B)
LOCATION AS SHOWN
ON SHEET 3 PLAN &
PROFILE
4.0' X 10.0' LIMIT
OF STRUCTUAL
SOIL
LA
LIMITS OF 30 MIL PLASTICIMPERMEABLE LINERAROUND STRUCTURAL SOIL
6" THICK, 18" DEEPENEDEDGE SIDEWALKTREATMENT, SEE SECTION
B-B BELOW
SPLASH PADPER GS-5.06
LA
ROW4.5'5'
4:1 SLOPE
4:1 SLOPE
0.5'
SIDEWALK
10' DIAMETER STREET TREE
WITH 160 CF MIN STRUCTURALSOIL (4.5' WIDE X 10' LONG X 4'DEEP)
6" PCC REINFORCED
CURB TYP. PER GS
STREET FLOW
PCCSIDEWALK PER
GS-1.04B
6" X 18"DEEPENEDEDGEREINFORCED
COMPACTED
SUBGRADE
COMPACTED
SUBGRADE
6" SAND
FILTER LAYER
4.0' LIMITS OF STRUCTURAL SOIL
ROOT BARRIERPER SDRSD L-6
30 MIL PLASTICIMPERMEABLE LINER
48" DEEPSTRUCTURAL SOIL*
DEEP ROOT TREEBUBBLER PERSDRSD DWG I-4
UNCOMPACTED SUBGRADE
3" MIN MULCH
LAYER
ROOT
BALL
1"
7" DEPRESSION@ CURB CUTPER DETAIL D-D
30 MIL PLASTIC
IMPERMEABLE LINER
SPLASHPAD PER SDC GS
DS GS-5.06
*6"
4:110"
*MODIFIED FROM STANDARD
6" SAND FILTERLAYER
10.0' LIMITS OF STRUCTURAL SOIL
ROOT BARRIER
PER SDRSD L-6
30 MIL PLASTIC
IMPERMEABLE LINER
48" DEEPSTRUCTURAL SOIL*
DEEP ROOT TREEBUBBLER PER
SDRSD DWG I-4UNCOMPACTED SUBGRADE
COMPACTED
SUBGRADEROOT
BALL
30 MIL PLASTIC
IMPERMEABLE LINER
3" MULCH
ADJACENT LANDSCAPED
PWKY ON ADAMS
STREET
COMPACTEDSUBGRADE
4:1
10"4:1
ADJACENT LANDSCAPED
PWKY ON ADAMS
STREET
ROOT BARRIER
PER SDRSD L-6
*MODIFIED FROM STANDARD
PLSA 3339-01
PLAN VIEW - DMA EXHIBIT
SCALE: 1" = 10' HORIZONTAL
10 20 30
GRAPHIC SCALE: 1" = 10'
010
LEGEND
PROPERTY BOUNDARY
CENTERLINE OF ROAD
RIGHT-OF-WAY
EXISTING CONTOUR LINE
DMA DRAINAGE BASIN BOUNDARY
PROPOSED IMPERVIOUS AREA WITHIN
ADAMS STREET RIGHT-OF-WAY DRAININGTO TREE WELL
PROPOSED ROUTINE MAINTENANCE ONEXISTING IMPERVIOUS AREA
IMPERVIOUS AREA DISPERSION
TREE WELL
DMA EXHIBIT - ATTACHMENT 1A_B
3745 ADAMS STREET
CITY OF CARLSBAD
256
SHEET 2 OF 2
ADAMS STREET ROW AREA CALCULATIONS
TOTAL AREA DISTURBED BY PROJECT (ROW)5,848 SF (0.13 AC)TOTAL PROPOSED / REPLACED IMPERVIOUS AREA (ROW)4,516 SF (0.10 AC)
DRAINAGE MANAGEMENT AREA EXHIBIT
ADAMS STREET WIDENING
J:\ACTIVE JOBS\3339 3745 ADAMS STREET\CIVIL\REPORTS\SWQMP\Final Engineering\Attachments\Attachment 1 - Pollutant Control\Att_1a-b - DMA.dwg
SECTION B-B - TREE WELL W/O GRATE (AT ADAMS STREET)
MODIFIED SDC GS DS GS-1.04a + GS-1.04b
SCALE: NOT TO SCALE
PLAN VIEW - TREE WELL W/O GRATE (AT ADAMS ST)
MODIFIED SDC GS DS GS-1.04a + GS-1.04b
SCALE: NOT TO SCALE
SECTION A-A - TREE WELL W/O GRATE (AT ADAMS ST)
MODIFIED SDC GS DS GS-1.04a + GS-1.04b
SCALE: NOT TO SCALESEE SHEET 1 FOR ONSITE DRAINAGE AREA CALCULATIONSDMA 3 - AREA CALCULATIONS
TOTAL BASIN AREA 1,187 SF
DMA 4 - AREA CALCULATIONS
TOTAL BASIN AREA 1,187 SF
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Appendix K: Forms and Checklists
K-2 Sept. 2021
Harvest and Use Feasibility Checklist Form K-7
1. Is there a demand for harvested water (check all that apply) at the project site that is reliably present during
the wet season?
Toilet and urinal flushing
Landscape irrigation
Other:______________
2. 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
B.3.2.
[Provide a summary of calculations here]
3. Calculate the DCV using worksheet B-2.1.
DCV = __________ (cubic feet)
3a. Is the 36 hour demand greater
than or equal to the DCV?
Yes / No
3b. Is the 36 hour demand greater than
0.25DCV but less than the full DCV?
Yes / No
3c. Is the 36 hour demand
less than 0.25DCV?
Yes
Harvest and use appears to be
feasible. Conduct more detailed
evaluation and sizing calculations
to confirm that DCV can be used
at an adequate rate to meet
drawdown criteria.
Harvest and use may be feasible.
Conduct more detailed evaluation and
sizing calculations to determine
feasibility. Harvest and use may only be
able to be used for a portion of the site,
or (optionally) the storage may need to be
upsized to meet long term capture targets
while draining in longer than 36 hours.
Harvest and use is
considered to be infeasible.
Is harvest and use feasible based on further evaluation?
Yes, refer to Appendix E to select and size harvest and use BMPs.
No, select alternate BMPs.
Note: 36-hour demand calculations are for feasibility analysis only. Once feasibility analysis is complete the
applicant may be allowed to use a different drawdown time provided they meet the 80% annual capture standard
(refer to B.4.2) and 96-hour vector control drawdown requirement.
Toilet and urinal flushing = 4.0 res. units x 4.0 residents / unit x 9.3 Gal / resident = 1498 GalLandscape irrigation = 0.45 AC * 1,470 Gal/AC/36hr = 661 Gal
Total = 149 Gal + 661 Gal = 810 Gal = 108 Cu Ft
X
X
992 (total)
X X X
X v--------I D "-. , 1t 1t ~ ¢::l ¢:I □ □ □
*
*See GEI Supplement letter dated March 30, 2022
BMP-1
Adams Street Homes 20-12852
Appendix D: Geotechnical Engineer Analysis
Appendix D Geotechnic al Engineer
Analysis
Ana lysis of Infiltration Restrictions
This section is only applicable if the analysis of infiltration restrictions is performed by a
licensed engineer practicing in geotechnical engineering. The SWQMP Preparer and
Geotechnical Engineer must work collaboratively to identify any infiltration restrictions identified in
Table 0.1-1 below. Upon completion of this section, the Geotechnical Engineer must characterize
each OMA as Restricted or Unrestricted for infiltration and provide adequate support/discussion in
the geotechnical report. A OMA is considered restricted when one or more restrictions exist which
cannot be reasonably resolved through site design changes.
Table D.1-1: Considerations for Geotechnical Analysis oflnfiltration Restrictions
Mandatory
Considerations
Optional
Considerations
Result
Restriction Element
BMP is within 100' of Contaminated Soils
BMP is within 100' of Industrial Activities Lacking Source Control
BMP is within 100' of Well/Groundwater Basin
BMP is within 50' of Septic Tanks/Leach Fields
BMP is within 10' of Structures/Tanks/Walls
BMP is within 1 O' of Sewer Utilities
BMP is within 10' of Groundwater Table
BMP is within Hydric Soils
BMP is within Highly Liquefiable Soils and has Connectivity to Structures
BMP is within 1.5 Times the Height of Adjacent Steep Slopes (~25%)
County Staff has Assigned ''Restricted" Infiltration Category
BMP is within Predominantly Type D Soil
BMP is within 1 O' of Property Line
BMP is within Fill Depths of ~5' (Existing or Proposed)
BMP is within 10' of Underground Utilities
BMP is within 250' of Ephemeral Stream
Other (Provide detailed geotechnical support)
Based on examination of the best available information,
Is Element
Applicable?
(Yes/No)
No
No
No
Yes
No
No
No
No
No
No
No
No
No
No
No
No
I have not identified any restrictions above. Unrestricted
Based on examination of the best available information, D
I have identified one or more restrictions above. Restricted
Table 0.1-1 is divided into Mandatory Considerations and Optional Considerations. Mandatory
D-1 Sept. 2021
Adams Street Homes 20-12852
Appendix D: Geotechnical Engineer Analysis
Considerations include elements that may pose a significant risk to human health and safety and must
always be evaluated. Optional Considerations include elements that are not necessarily associated with
human health and safety, so analysis is not mandated through this guidance document. All elements
presented in this table are subject to the discretion of the Geotechnical Engineer if adequate
supporting information is provided.
Applicants must evaluate infiltration restrictions through use of the best available data. A list of
resources available for evaluation is provided in Section B.2
Determination of Design Infiltratio n Rates
This section is only applicable if the determination of design infiltration rates is performed
by a licensed engineer practicing in geotechnical engineering. The guidance in this section
identifies methods for identifying observed infiltration rates, corrected infiltration rates, safety factors,
and design infiltration rates for use in structural BMP design. Upon completion of this section, the
Geotechnical Engineer must recommend a design infiltration rate for each OMA and provide
adequate support/ discussion in the geotechnical report.
Table D.2-1: Elements for Detennination of Design Infiltration Rates
Item Value Unit
Initial Infiltration Rate 1.694 in/hr Identify per Section D.2.1
Corrected Infiltration Rate
Identify per Section D.2.2 1.38 in/hr
Safety Factor 2 unitless Identify per Section D.2.3
Design Infiltration Rate
in/hr Corrected Infiltration Rate + Safety Factor 0.69
D-2 Sept.2021
Appendix K: Forms and Checklists
K-3 Sept. 2021
Factor of Safety and Design Infiltration Rate
Worksheet Form K-9
Factor Category Factor Description Assigned
Weight (w)
Factor
Value (v)
Product (p)
p = w x v
A Suitability
Assessment
Soil assessment methods 0.25
Predominant soil texture 0.25
Site soil variability 0.25
Depth to groundwater / impervious
layer 0.25
Suitability Assessment Safety Factor, SA = p
B Design
Level of pretreatment/ expected
sediment loads 0.5
Redundancy/resiliency 0.25
Compaction during construction 0.25
Design Safety Factor, SB = p
Combined Safety Factor, Stotal= SA x SB
Observed Infiltration Rate, inch/hr, Kobserved
(corrected for test-specific bias)
Design Infiltration Rate, in/hr, Kdesign = Kobserved / Stotal
Supporting Data
Briefly describe infiltration test and provide reference to test forms:
2
1
2
1.0
0.25
0.50
1.75
3.5
1.694
0.48
See I-8 form, Part 1, Criteria 1 for information on infiltration testing and methods used, etc.
2
2
3
1
0.5
0.5
0.75
0.25
2.0
*
*See GEI Supplement letter dated March 30, 2022
BMP-2
Adams Street Homes 20-12852
Appendix D: Geotechnical Engineer Analysis
Appendix D Geotechnic al Engineer
Analysis
Ana lysis of Infiltration Restrictions
This section is only applicable if the analysis of infiltration restrictions is performed by a
licensed engineer practicing in geotechnical engineering. The SWQMP Preparer and
Geotechnical Engineer must work collaboratively to identify any infiltration restrictions identified in
Table 0.1-1 below. Upon completion of this section, the Geotechnical Engineer must characterize
each OMA as Restricted or Unrestricted for infiltration and provide adequate support/discussion in
the geotechnical report. A OMA is considered restricted when one or more restrictions exist which
cannot be reasonably resolved through site design changes.
Table D.1-1: Considerations for Geotechnical Analysis oflnfiltration Restrictions
Mandatory
Considerations
Optional
Considerations
Result
Restriction Element
BMP is within 100' of Contaminated Soils
BMP is within 100' of Industrial Activities Lacking Source Control
BMP is within 100' of Well/Groundwater Basin
BMP is within 50' of Septic Tanks/Leach Fields
BMP is within 10' of Structures/Tanks/Walls
BMP is within 1 O' of Sewer Utilities
BMP is within 10' of Groundwater Table
BMP is within Hydric Soils
BMP is within Highly Liquefiable Soils and has Connectivity to Structures
BMP is within 1.5 Times the Height of Adjacent Steep Slopes (~25%)
County Staff has Assigned ''Restricted" Infiltration Category
BMP is within Predominantly Type D Soil
BMP is within 1 O' of Property Line
BMP is within Fill Depths of ~5' (Existing or Proposed)
BMP is within 10' of Underground Utilities
BMP is within 250' of Ephemeral Stream
Other (Provide detailed geotechnical support)
Based on examination of the best available information,
Is Element
Applicable?
(Yes/No)
No
No
No
Yes
No
No
No
No
No
No
No
No
No
No
No
No
I have not identified any restrictions above. Unrestricted
Based on examination of the best available information, D
I have identified one or more restrictions above. Restricted
Table 0.1-1 is divided into Mandatory Considerations and Optional Considerations. Mandatory
D-1 Sept. 2021
Adams Street Homes 20-12852
Appendix D: Geotechnical Engineer Analysis
Considerations include elements that may pose a significant risk to human health and safety and must
always be evaluated. Optional Considerations include elements that are not necessarily associated with
human health and safety, so analysis is not mandated through this guidance document. All elements
presented in this table are subject to the discretion of the Geotechnical Engineer if adequate
supporting information is provided.
Applicants must evaluate infiltration restrictions through use of the best available data. A list of
resources available for evaluation is provided in Section B.2
Determination of Design Infiltratio n Rates
This section is only applicable if the determination of design infiltration rates is performed
by a licensed engineer practicing in geotechnical engineering. The guidance in this section
identifies methods for identifying observed infiltration rates, corrected infiltration rates, safety factors,
and design infiltration rates for use in structural BMP design. Upon completion of this section, the
Geotechnical Engineer must recommend a design infiltration rate for each OMA and provide
adequate support/ discussion in the geotechnical report.
Table D.2-1: Elements for Detennination of Design Infiltration Rates
Item Value Unit
Initial Infiltration Rate 1.694 in/hr Identify per Section D.2.1
Corrected Infiltration Rate
Identify per Section D.2.2 1.38 in/hr
Safety Factor 2 unitless Identify per Section D.2.3
Design Infiltration Rate
in/hr Corrected Infiltration Rate + Safety Factor 0.69
D-2 Sept.2021
Appendix K: Forms and Checklists
K-3 Sept. 2021
Factor of Safety and Design Infiltration Rate
Worksheet Form K-9
Factor Category Factor Description Assigned
Weight (w)
Factor
Value (v)
Product (p)
p = w x v
A Suitability
Assessment
Soil assessment methods 0.25
Predominant soil texture 0.25
Site soil variability 0.25
Depth to groundwater / impervious
layer 0.25
Suitability Assessment Safety Factor, SA = p
B Design
Level of pretreatment/ expected
sediment loads 0.5
Redundancy/resiliency 0.25
Compaction during construction 0.25
Design Safety Factor, SB = p
Combined Safety Factor, Stotal= SA x SB
Observed Infiltration Rate, inch/hr, Kobserved
(corrected for test-specific bias)
Design Infiltration Rate, in/hr, Kdesign = Kobserved / Stotal
Supporting Data
Briefly describe infiltration test and provide reference to test forms:
2
1
2
1.0
0.25
0.50
1.75
3.5
1.694
0.48
See I-8 form, Part 1, Criteria 1 for information on infiltration testing and methods used, etc.
2
2
3
1
0.5
0.5
0.75
0.25
2.0
Simple Open Pit Rate to Infiltration Rate Conversion (Porchet Method)
Project Name: Adams Street Homes
Project No. 20-12852
Test Hole No: INF-2
Test EB Depth DeltaT Water Depth
No. (inches) (min) 1 (inches)
1 30 45 23.875
2 30 60 24.000
3 30 60 24.000
4
5
6
7
8
9
Calculated By: SO
Checked By:
Date: 8/3/2020
Date:
Test Hole Dia: 24" Depth ofTest Hole: 30"
Porchet Corrections
Infiltration rate=((delta h*60r)/(delta t*(r+2 h avg))
Water Depth hl h2 delta h havg r (radius)
2 (inches) (Inches) (Inches) (inches) (inches) (inches)
30.000 6.125 0.000 6.125 3.063 12
30.000 6.000 0.000 6.000 3.000 12
29.125 6.000 0.875 5.125 3.438 12
delta
h*60r
4410
4320
3690
delta t*(r+2 Infiltration rate
h avf!:) (in/hr)
815.625 5.407
1080 4.000
1132.5 3.258
Simple Open Pit Rate to Infiltration Rate Conversion (Porchet Method)
Project Name: Adams Street Homes
Project No. 20-12852
Test Hole No: INF-1
Test EB Depth Delta T Water Depth
No. (inches) (min) 1 (inches)
1 24 60 17.500
2 24 60 18.000
3 24 60 17.875
4
5
6
7
8
9
Calculated By: SO
Checked By:
Test Hole Dia: 24"
Date: 8/3/2019
Date:
Depth of Test Hole: 24"
Porchet Corrections
Infiltration rate=((delta h*60r)/(delta t*(r+2 h avg))
Water Depth hl h2 delta h havg
2 (Inches) (inches) (inches) (Inches) (Inches)
23.500 6.500 0.500 6.000 3.500
23.125 6.000 0.875 5.125 3.438
20.875 6.125 3.125 3.000 4.625
r (radius) delta delta t*fr+2 h
(Inches) h*60r ave)
12 4320 1140
12 3690 1132.5
12 2160 1275
Infiltration
rate (in/hr)
3.789
3.258
1.694
Simple Open Pit Falling Head Test Sheet
Project Name: Adams Street Homes
Project No. 20-12852
Date Excavated: 8/3/20
Test Hole No: INF-1
Initial Time (Minutes) Final Time (Minutes)
1145 1245
1250 1350
1355 1455
Time Interval
(minutes)
60
60
60
Initial Water Level
(inches)
17.500
18.000
17.875
Tested By: SO
Soll Classlflcation: SM
Depth of Test Hole: 24"
Test Hole Dia: 24"
Final Water Level
(Inches)
23.500
23.125
20.875
Change In water
(Inches)
6.000
5.125
3.000
Falling Head Rate
(min/inches)
10.000
11.707
20.000
Simple Open Pit Falling Head Test Sheet
Project Name: Adams Street Homes
Project No. 20-12852
Date Excavated: 8/3/20
Test Hole No: INF-2
Initial Time (Minutes) Final Time (Minutes)
1150 1235
1240 1340
1345 1445
Time Interval
(minutes)
45
60
60
Initial Water Level
(Inches)
23.875
23.500
24.000
Tested By: SO
Soll Classification: SM
Depth of Test Hole: 30"
Test Hole Dia: 24"
Final Water Level
(inches)
30.000
30.000
29.125
Change In water
(inches)
6.125
6.500
5.125
Falling Head Rate
(min/Inches)
7.347
9.231
11.707
I
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&'Xl.J'
PCCS
CONVERT R
TO SHEET
.umGA
0100 = 0.62CF
l!ltf'GJ•
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813ft --Q)
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rU.7FG}
MZFS
LOT3
PROP. SFR
FF=88.2
PAD=87.5
PROP.ADU
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PAD=90.7
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;?l,f fVc
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s:' ii< "' ~ a; ::; ', ~ I ~ .., a I ~ C, i
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I"= 10' -----,. D fJ :i,
Scale: 1" = l O'
(approximate)
PLOT PLAN AND
SITE SPECIFIC
GEOLOGIC MAP
Adams Street Homes
3745 Adams Street
Carlsbad, CA.
Figure No. I/
Job No. 20-12852
~
!J
Geotechnical Exploration, Inc.
March 2022
PASCO LARET SUITER
s.;, c,~-go ~/J1\~ Bs:ac~ ~I ~5}~~';1t~~l~
t>r:,.,t 'l~S 1S9 ~]ll ! ,·n.,,;,:, !!trgr.~"°ri,i<'-''"
LEGEND
Approximate Location \;-9 of Exploratory Trench
e INF-2 Approximate Location
of Infiltration Test
( Approximate Location of -__) Proposed Biofiltration Basin
GEOLOGY LEGEND
Qaf
Qop
2-4
Artificial Fill
Old Paralic Deposits
( units 2-4)
NOTE: Tnis F'lol Flln 15 ro\ lo [X' tJ&ed kr ,~11
pu,i:;.;ses Lo:<11jons :1t1d dimens 005 :ire appro;,.imal.~
A'.;1•.J.JI p:o;,eny di~ C'fl:I !!rd l::~'.ICIB ct ulll•Eres
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RCE 03912 EXPRg 9/30/22 DATE
PRo.ECT NO. Ol!AV..NG NO,
MS 2020-0004 534-SA
Fl.s.tJJjicr
Category #Description i ii Units
1 Drainage Basin ID or Name 1 2 unitless
2 85th Percentile 24-hr Storm Depth 0.60 0.60 inches
3 Impervious Surfaces Not Directed to Dispersion Area (C=0.90) 15,525 4,524 sq-ft
4 Semi-Pervious Surfaces Not Serving as Dispersion Area (C=0.30)sq-ft
5 Engineered Pervious Surfaces Not Serving as Dispersion Area (C=0.10)12,940 5,030 sq-ft
6 Natural Type A Soil Not Serving as Dispersion Area (C=0.10)sq-ft
7 Natural Type B Soil Not Serving as Dispersion Area (C=0.14)sq-ft
8 Natural Type C Soil Not Serving as Dispersion Area (C=0.23)sq-ft
9 Natural Type D Soil Not Serving as Dispersion Area (C=0.30)sq-ft
10 Does Tributary Incorporate Dispersion, Tree Wells, and/or Rain Barrels?No No yes/no
11 Impervious Surfaces Directed to Dispersion Area per SD-B (Ci=0.90) sq-ft
12 Semi-Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.30)sq-ft
13 Engineered Pervious Surfaces Serving as Dispersion Area per SD-B (Ci=0.10)sq-ft
14 Natural Type A Soil Serving as Dispersion Area per SD-B (Ci=0.10)sq-ft
15 Natural Type B Soil Serving as Dispersion Area per SD-B (Ci=0.14)sq-ft
16 Natural Type C Soil Serving as Dispersion Area per SD-B (Ci=0.23)sq-ft
17 Natural Type D Soil Serving as Dispersion Area per SD-B (Ci=0.30)sq-ft
18 Number of Tree Wells Proposed per SD-A #
19 Average Mature Tree Canopy Diameter ft
20 Number of Rain Barrels Proposed per SD-E #
21 Average Rain Barrel Size gal
22 Total Tributary Area 28,465 9,554 sq-ft
23 Initial Runoff Factor for Standard Drainage Areas 0.54 0.48 unitless
24 Initial Runoff Factor for Dispersed & Dispersion Areas 0.00 0.00 unitless
25 Initial Weighted Runoff Factor 0.54 0.48 unitless
26 Initial Design Capture Volume 769 229 cubic-feet
27 Total Impervious Area Dispersed to Pervious Surface 0 0 sq-ft
28 Total Pervious Dispersion Area 0 0 sq-ft
29 Ratio of Dispersed Impervious Area to Pervious Dispersion Area n/a n/a ratio
30 Adjustment Factor for Dispersed & Dispersion Areas 1.00 1.00 ratio
31 Runoff Factor After Dispersion Techniques 0.54 0.48 unitless
32 Design Capture Volume After Dispersion Techniques 769 229 cubic-feet
33 Total Tree Well Volume Reduction 0 0 cubic-feet
34 Total Rain Barrel Volume Reduction 0 0 cubic-feet
35 Final Adjusted Runoff Factor 0.54 0.48 unitless
36 Final Effective Tributary Area 15,371 4,586 sq-ft
37 Initial Design Capture Volume Retained by Site Design Elements 0 0 cubic-feet
38 Final Design Capture Volume Tributary to BMP 769 229 cubic-feet
False
False
Automated Worksheet B.1: Calculation of Design Capture Volume (V2.0)
Dispersion
Area, Tree Well
& Rain Barrel
Inputs
(Optional)
Standard
Drainage Basin
Inputs
Results
Tree & Barrel
Adjustments
Initial Runoff
Factor
Calculation
Dispersion
Area
Adjustments
No Warning Messages
Category #Description i ii Units
1 Drainage Basin ID or Name 1 2 unitless
2 85th Percentile Rainfall Depth 0.60 0.60 inches
3 Predominant NRCS Soil Type Within BMP Location B B unitless
4 Is proposed BMP location Restricted or Unrestricted for Infiltration Activities? Unrestricted Unrestricted unitless
5 Nature of Restriction unitless
6 Do Minimum Retention Requirements Apply to this Project?Yes Yes yes/no
7 Are Habitable Structures Greater than 9 Stories Proposed?No No yes/no
8 Has Geotechnical Engineer Performed an Infiltration Analysis?Yes Yes yes/no
9 Design Infiltration Rate Recommended by Geotechnical Engineer 0.480 0.480 in/hr
10 Design Infiltration Rate Used To Determine Retention Requirements 0.480 0.480 in/hr
11 Percent of Average Annual Runoff that Must be Retained within DMA 40.0%40.0%percentage
12 Fraction of DCV Requiring Retention 0.32 0.32 ratio
13 Required Retention Volume 246 73 cubic-feet
-Retention requirements have been omitted in these calculations. Such an omission is only be acceptable for Green Street projects or projects that submit
False
Automated Worksheet B.2: Retention Requirements (V2.0)
Advanced
Analysis
Basic Analysis
Result
Attention!
Category #Description i ii Units
1 Drainage Basin ID or Name 1 2 sq-ft
2 Design Infiltration Rate Recommended 0.480 0.480 in/hr
3 Design Capture Volume Tributary to BMP 769 229 cubic-feet
4 Is BMP Vegetated or Unvegetated?Vegetated Vegetated unitless
5 Is BMP Impermeably Lined or Unlined?Unlined Unlined unitless
6 Does BMP Have an Underdrain?Underdrain Underdrain unitless
7 Does BMP Utilize Standard or Specialized Media?Standard Standard unitless
8 Provided Surface Area 700 275 sq-ft
9 Provided Surface Ponding Depth 18 12 inches
10 Provided Soil Media Thickness 18 18 inches
11 Provided Gravel Thickness (Total Thickness)18 18 inches
12 Underdrain Offset 3 3 inches
13 Diameter of Underdrain or Hydromod Orifice (Select Smallest)0.50 0.40 inches
14 Specialized Soil Media Filtration Rate in/hr
15 Specialized Soil Media Pore Space for Retention unitless
16 Specialized Soil Media Pore Space for Biofiltration unitless
17 Specialized Gravel Media Pore Space unitless
18 Volume Infiltrated Over 6 Hour Storm 168 66 cubic-feet
19 Ponding Pore Space Available for Retention 0.00 0.00 unitless
20 Soil Media Pore Space Available for Retention 0.05 0.05 unitless
21 Gravel Pore Space Available for Retention (Above Underdrain)0.00 0.00 unitless
22 Gravel Pore Space Available for Retention (Below Underdrain)0.40 0.40 unitless
23 Effective Retention Depth 2.10 2.10 inches
24 Fraction of DCV Retained (Independent of Drawdown Time)0.38 0.50 ratio
25 Calculated Retention Storage Drawdown Time 6 6 hours
26 Efficacy of Retention Processes 1.00 1.00 ratio
27 Volume Retained by BMP (Considering Drawdown Time)769 229 cubic-feet
28 Design Capture Volume Remaining for Biofiltration 0 0 cubic-feet
29 Max Hydromod Flow Rate through Underdrain 0.0135 0.0081 cfs
30 Max Soil Filtration Rate Allowed by Underdrain Orifice 0.83 1.28 in/hr
31 Soil Media Filtration Rate per Specifications 5.00 5.00 in/hr
32 Soil Media Filtration Rate to be used for Sizing 0.83 1.28 in/hr
33 Depth Biofiltered Over 6 Hour Storm 5.00 7.65 inches
34 Ponding Pore Space Available for Biofiltration 1.00 1.00 unitless
35 Soil Media Pore Space Available for Biofiltration 0.20 0.20 unitless
36 Gravel Pore Space Available for Biofiltration (Above Underdrain)0.40 0.40 unitless
37 Effective Depth of Biofiltration Storage 27.60 21.60 inches
38 Drawdown Time for Surface Ponding 14 7 hours
39 Drawdown Time for Effective Biofiltration Depth 21 12 hours
40 Total Depth Biofiltered 32.60 29.25 inches
41 Option 1 - Biofilter 1.50 DCV: Target Volume 0 0 cubic-feet
42 Option 1 - Provided Biofiltration Volume 0 0 cubic-feet
43 Option 2 - Store 0.75 DCV: Target Volume 0 0 cubic-feet
44 Option 2 - Provided Storage Volume 0 0 cubic-feet
45 Portion of Biofiltration Performance Standard Satisfied 0.00 0.00 ratio
46 Do Site Design Elements and BMPs Satisfy Annual Retention Requirements?Yes Yes yes/no
47 Overall Portion of Performance Standard Satisfied (BMP Efficacy Factor)1.00 1.00 ratio
48 Deficit of Effectively Treated Stormwater 0 0 cubic-feet
Biofiltration
Calculations
-This BMP does not fully satisfy the performance standards for pollutant control for the drainage area.
False
False
False
Result
False
False
Attention!
Retention
Calculations
Automated Worksheet B.3: BMP Performance (V2.0)
False
False
BMP Inputs
P.O. Box 837
259 Murdock Road
Troutman, NC
(800) 438-6057
(704) 528-9806
www.ABTDRAINS.com
3.27 kg
710 mm
Weight per unit 7.21 lbs
Length 27.95 in
Width 355 mm13.98 in
Depth 150 mm5.91 in
PðArea per unit IWð
Occupied volume per unit PñIWñ
Vertical compressive yield 715 kPa103.7 psi
Lateral compressive yield 156 kPa22.6 psi
Vertical deflection strength 126 kPa/mm464 psi / in
Lateral deflection strength 15 kPa/mm55.3 psi / in
Tensile strength at single joint 42.4 kPa6.15 psi
Bending resistance of unit 0.71 kN-m524 lb-ft
Bending resistance of single joint 0.16 kN-m118 lb-ft
Average perforated surface area 52 %
Volumetric void ratio
Void volume per unit PñIWñ
Conveyance at 0.0% Slope
95 %
Conveyance at 1.0% Slope
Conveyance at 2.0% Slope
Conveyance at 3.0% Slope
Material Polypropylene
Permavoid 150 (PV150) structural cells are multi-functional water management solutions
that promote sustainable stormwater behavior. The interconnected, high-strength units
create a patented subbase replacement system that attenuates stormwater flows and, when
feasible, promotes infiltration even beneath impervious surfaces. Units can be stacked to
create multi-layer tanks to fit nearly any site constraints while eliminating the need for
traditional conveyance schemes. Permavoid systems can also enhance landscape
resiliency through patented capillary cylinders that wick stormwater up toward vegetation
without the need for sprinklers, pumps or energy to create the ultimate low impact solution.
Recycled content 100 %
Recyclability
Country of origin
100 %
United States of America
Vertical creep limit (100 year)165 kPa24 psi
PHYSICAL PROPERTIES
STRUCTURAL PROPERTIES
HYDRAULIC PROPERTIES
OTHER PROPERTIES
Permavoid 150 Data Sheet 03-20
Proprietary rights of ABT, Inc. are included in the information disclosed herein. The recipient, by accepting this document, agrees that neither
this document nor the information disclosed herein nor any part thereof shall be copied, reproduced or transferred to others for manufacturing
or for any other purpose except as specifically authorized in writing by ABT, Inc.
Disclaimer: The customer and the customer's architects, engineers, consultants and other professionals are completely responsible for the
selection, installation, and maintenance of any product purchased from ABT, and EXCEPT AS EXPRESSLY PROVIDED IN ABT'S STANDARD
WARRANTIES, ABT MAKES NO WARRANTY, EXPRESS OR IMPLIED, AS TO THE SUITABILITY, DESIGN, MERCHANTABILITY, OR
FITNESS OF THE PRODUCT FOR CUSTOMER'S APPLICATION. Copies of ABT's standard warranties are available upon request.
Tie Connector (PVTIE)
2x required per tie slot
Shear Connector (PVSC)
1x required per unit between layers (traffic)
1x required per 3 units between layers (non-traffic)
Capillary Irrigation Cone (2 pieces)
PVWC-35/42 + PVWC-27/113
2x required per unit
Capillary Geotextile (Permatex CAP HP)
Required for capillary irrigation applications
All sides wrapped with 12" [300mm] lap joints min.
ACCESSORIES GEOTEXTILES
The following are for guidance only. Refer to design
documents for site specific requirements.
1. Non-woven fabric for separation and/or infiltration:
- Tencate - Mirafi 1100N (or approved equal)
2. Woven fabric for separation and/or infiltration:
- Tencate - Mirafi HP270 (or approved equal)
3. Waterproof Membrane Liner for retention and/or detention:
- 40 mil HDPE or LLDPE (or approved equal)
/36Pð*30IWð
*30IWð
*30IWð
*30IWð
/36Pð
/36Pð
/36Pð
27.95"
[710mm]
5.91"
[150mm]
13.98"
[355mm]
3 X 5.9" STACK = ~18"
I
A11·1NC. ~J
WATER MATTERS "II/)
PR-1 Biofiltration with Partial Retention
E-93 Sept. 2021
PR-1 Biofiltration with Partial Retention
Location: 805 and Bonita Road, Chula vista, CA.
Description
Biofiltration with partial retention (partial infiltration and biofiltration) facilities are vegetated surface
water systems that filter water through vegetation, and soil or engineered media prior to infiltrating
into native soils, discharge via underdrain, or overflow to the downstream conveyance system. Where
feasible, these BMPs have an elevated underdrain discharge point that creates storage capacity in the
aggregate storage layer. Biofiltration with partial retention facilities are commonly incorporated into
the site within parking lot landscaping, along roadsides, and in open spaces. They can be constructed
in ground or partially aboveground, such as planter boxes with open bottoms to allow infiltration.
Treatment is achieved through filtration, sedimentation, sorption, infiltration, biochemical processes
and plant uptake.
Typical biofiltration with partial retention components include:
• Inflow distribution mechanisms (e.g, perimeter flow spreader or filter strips)
• Energy dissipation mechanism for concentrated inflows (e.g., splash blocks or riprap)
• Shallow surface ponding for captured flows
• Side Slope and basin bottom vegetation selected based on climate and ponding depth
• Non-floating mulch layer (Optional)
• Media layer (planting mix or engineered media) capable of supporting vegetation growth
• Filter course layer consisting of aggregate to prevent the migration of fines into uncompacted
native soils or the optional aggregate storage layer
• Aggregate storage layer with underdrain(s)
• Uncompacted native soils at the bottom of the facility
• Overflow structure
MS4 Permit Category
NA
Manual Category
Partial Retention
Applicable Performance
Standard
Pollutant Control
Flow Control
Primary Benefits
Volume Reduction
Treatment
Peak Flow Attenuation
E.12
PR-1 Biofiltration with Partial Retention
E-94 Sept. 2021
Typical plan and Section view of a Biofiltration with Partial Retention BMP
& ABOVE
MIN. 6” FREEBOARD
MAX. 1:1
...... .. ..
PRON
ISSIPA
..,3H:1V (MIN.) ..
+ + ... +
+ + .., ...
+ + + +
+ + + +
·MAINTENANCE ..
ACCESS
JAS !-1EE_E)EDJ "'
+ + + + 3H:1V (MIN.) ..,
<<\ .. < ~
VEGETATED
SIDE SLOPE
PLAN
NOTTO SCALE
4-6" DROP FROM CURB CUT TO APRON
APRON FOR ENERGY DISSIPATION
EXCAVATED SLOPE
MIN. 18" MEDIA WITH MIN7
5 IN/HR FILTRATION RATE
INFILTRATION STORAGE (MIN.
3" AGGREGATE BELOW
UNDERDRAIN)
AGGREGATE STORAGE LAYER
3" WELL-AGED, SHREDDED HARDWOOD MULCH
6" MIN. TO 12" MAX.
SURFACE PONDING
UNDERDRAIN
FILTER COURSE
OVERFLOW
STRUCTURE
EXISTING UNCOMPACTED SOILS
SECTION A-A'
NOTTO SCALE
MAINTENANCE
ACCESS
(AS NEEDED)
PR-1 Biofiltration with Partial Retention
E-95 Sept. 2021
Design Adaptations for Project Goals
Partial infiltration BMP with biofiltration treatment for storm water pollutant control.
Biofiltration with partial retention can be designed so that a portion of the DCV is infiltrated by
providing infiltration storage below the underdrain invert. The infiltration storage depth should be
determined by the volume that can be reliably infiltrated within drawdown time limitations. Water
discharged through the underdrain is considered biofiltration treatment. Storage provided above the
underdrain within surface ponding, media, and aggregate storage is included in the biofiltration
treatment volume.
Integrated storm water flow control and pollutant control configuration. The system can be
designed to provide flow rate and duration control by primarily providing increased surface ponding
and/or having a deeper aggregate storage layer. This will allow for significant detention storage, which
can be controlled via inclusion of an orifice in an outlet structure at the downstream end of the
underdrain.
Recommended Siting Criteria
Siting Criteria Intent/Rationale
□
Placement observes geotechnical
recommendations regarding potential
hazards (e.g., slope stability, landslides,
liquefaction zones) and setbacks (e.g.,
slopes, foundations, utilities).
Must not negatively impact existing site
geotechnical concerns.
□
Selection and design of basin is based
on infiltration feasibility criteria and
appropriate design infiltration rate (See
Appendix D).
Must operate as a partial infiltration design and
must be supported by drainage area and in-situ
infiltration rate feasibility findings.
□ Contributing tributary area shall be ≤ 5
acres (≤ 1 acre preferred).
Bigger BMPs require additional design features
for proper performance.
Contributing tributary area greater than 5 acres
may be allowed at the discretion of the [City
Engineer} if the following conditions are met:
1) incorporate design features (e.g. flow
spreaders) to minimizing short circuiting of
flows in the BMP and 2) incorporate
additional design features requested by the
City Engineer for proper performance of the
regional BMP.
PR-1 Biofiltration with Partial Retention
E-96 Sept. 2021
Siting Criteria Intent/Rationale
□ Finish grade of the facility is ≤ 2%. Flatter surfaces reduce erosion and
channelization within the facility.
Recommended BMP Component Dimensions
BMP Component Dimension Intent/Rationale
Freeboard ≥ 6 inches
Freeboard provides room for head
over overflow structures and
minimizes risk of uncontrolled
surface discharge.
Surface Ponding ≥ 6 and ≤ 12 inches
Surface ponding capacity lowers
subsurface storage requirements.
Deep surface ponding raises safety
concerns.
Surface ponding depth greater than
12 inches (for additional pollutant
control or surface outlet structures
or flow-control orifices) may be
allowed at the discretion of the City
Engineer if the following
conditions are met: 1) surface
ponding depth drawdown time is
less than 24 hours; and 2) safety
issues and fencing requirements are
considered (typically ponding
greater than 18” will require a fence
and/or flatter side slopes) and 3)
potential for elevated clogging risk
is considered.
Ponding Area Side Slopes 3H:1V or shallower
Gentler side slopes are safer, less
prone to erosion, able to establish
vegetation more quickly and easier
to maintain.
Mulch ≥ 3 inches
Mulch will suppress weeds and
maintain moisture for plant growth.
Aging mulch kills pathogens and
weed seeds and allows the
beneficial microbes to multiply.
PR-1 Biofiltration with Partial Retention
E-97 Sept. 2021
BMP Component Dimension Intent/Rationale
Media Layer
≥ 18 inches
1:1 slope maximum for edge
condition
A deep media layer provides
additional filtration and supports
plants with deeper roots.
Standard specifications shall be
followed.
For non-standard or proprietary
designs, compliance with Appendix
F.1 ensures that adequate treatment
performance will be provided.
Underdrain Diameter ≥ 6 inches Smaller diameter underdrains are
prone to clogging.
Cleanout Diameter ≥ 6 inches Properly spaced cleanouts will
facilitate underdrain maintenance.
Design Criteria and Considerations
Biofiltration with partial retention must meet the following design criteria and considerations.
Deviations from the below criteria may be approved at the discretion of the City Engineer if it is
determined to be appropriate:
Design Criteria Intent/Rationale
Surface Ponding
□ Surface ponding is limited to a 24-hour
drawdown time.
Surface ponding limited to 24 hours for
plant health. Surface ponding drawdown
time greater than 24-hours but less than
96 hours may be allowed at the
discretion of the City Engineer if
certified by a landscape architect or
agronomist.
Vegetation
□ Plantings are suitable for the climate and
expected ponding depth. A plant list to aid in
selection can be found in Appendix E.21
Plants suited to the climate and ponding
depth are more likely to survive.
PR-1 Biofiltration with Partial Retention
E-98 Sept. 2021
Design Criteria Intent/Rationale
□ An irrigation system with a connection to
water supply should be provided as needed.
Seasonal irrigation might be needed to
keep plants healthy.
Mulch (Optional)
□
A minimum of 3 inches of well-aged, shredded
hardwood mulch that has been stockpiled or
stored for at least 12 months is provided.
Mulch must be non-floating to avoid clogging
of overflow structure.
Mulch will suppress weeds and maintain
moisture for plant growth. Aging mulch
kills pathogens and weed seeds and
allows the beneficial microbes to
multiply.
Media Layer
□
Media maintains a minimum filtration rate of 5
in/hr over lifetime of facility. An initial
filtration rate of 8 to 12 in/hr is recommended
to allow for clogging over time; the initial
filtration rate should not exceed 12 inches per
hour.
A filtration rate of at least 5 inches per
hour allows soil to drain between events,
and allows flows to relatively quickly
enter the aggregate storage layer, thereby
minimizing bypass. The initial rate
should be higher than long term target
rate to account for clogging over time.
However an excessively high initial rate
can have a negative impact on treatment
performance, therefore an upper limit is
needed.
□
Media is a minimum 18 inches deep, meeting
either of these two media specifications:
Section F.3 Bioretention Soil Media (BSM) or
specific jurisdictional guidance.
Alternatively, for proprietary designs and
custom media mixes not meeting the media
specifications, the media meets the pollutant
treatment performance criteria in Section F.1.
A deep media layer provides additional
filtration and supports plants with deeper
roots.
Standard specifications shall be followed.
For non-standard or proprietary designs,
compliance with Appendix F.1 ensures
that adequate treatment performance will
be provided.
□
Media surface area is 3% of contributing area
times adjusted runoff factor or greater. Unless
demonstrated that the BMP surface area can
be smaller than 3%.
Greater surface area to tributary area
ratios: a) maximizes volume retention as
required by the MS4 Permit and
b) decrease loading rates per square foot
and therefore increase longevity.
Adjusted runoff factor is to account for
site design BMPs implemented upstream
PR-1 Biofiltration with Partial Retention
E-99 Sept. 2021
Design Criteria Intent/Rationale
of the BMP (such as rain barrels,
impervious area dispersion, etc.). Refer
to Appendix B.1 guidance.
□
Where receiving waters are impaired or have a
TMDL for nutrients, the system is designed
with nutrient sensitive media design (see fact
sheet BF-2).
Potential for pollutant export is partly a
function of media composition; media
design must minimize potential for
export of nutrients, particularly where
receiving waters are impaired for
nutrients.
Filter Course Layer
□ A filter course is used to prevent migration of
fines through layers of the facility. Filter fabric
is not used.
Migration of media can cause clogging of
the aggregate storage layer void spaces or
subgrade. Filter fabric is more likely to
clog.
□ Filter course is washed and free of fines. Washing aggregate will help eliminate
fines that could clog the facility
□ Filter course calculations assessing suitability
for particle migration prevention have been
completed.
Gradation relationship between layers
can evaluate factors (e.g., bridging,
permeability, and uniformity) to
determine if particle sizing is appropriate
or if an intermediate layer is needed.
Aggregate Storage Layer
□
Class 2 Permeable per Caltrans specification
68-1.025 is recommended for the storage layer.
Washed, open-graded crushed rock may be
used, however a 4-6 inch washed pea gravel
filter course layer at the top of the crushed
rock is required.
Washing aggregate will help eliminate
fines that could clog the aggregate
storage layer void spaces or subgrade.
□
Maximum aggregate storage layer depth below
the underdrain invert is determined based on
the infiltration storage volume that will
infiltrate within a 36-hour drawdown time.
A maximum drawdown time is needed
for vector control and to facilitate
providing storm water storage for the
next storm event.
Inflow, Underdrain, and Outflow Structures
□ Inflow, underdrains and outflow structures are
accessible for inspection and maintenance.
Maintenance will prevent clogging and
ensure proper operation of the flow
control structures.
PR-1 Biofiltration with Partial Retention
E-100 Sept. 2021
Design Criteria Intent/Rationale
□ Inflow velocities are limited to 3 ft/s or less or
use energy dissipation methods. (e.g., riprap,
level spreader) for concentrated inflows.
High inflow velocities can cause erosion,
scour and/or channeling.
□ Curb cut inlets are at least 12 inches wide, have
a 4-6 inch reveal (drop) and an apron and
energy dissipation as needed.
Inlets must not restrict flow and apron
prevents blockage from vegetation as it
grows in. Energy dissipation prevents
erosion.
□ Underdrain outlet elevation should be a
minimum of 3 inches above the bottom
elevation of the aggregate storage layer.
A minimal separation from subgrade or
the liner lessens the risk of fines entering
the underdrain and can improve
hydraulic performance by allowing
perforations to remain unblocked.
□ Minimum of 3 inches of aggregate storage
layer from top of underdrain to bottom of
filter course.
To prevent potential clogging of the
underdrain and must not restrict flow.
□ Minimum underdrain diameter is 6 inches. Smaller diameter underdrains are prone
to clogging.
□
Underdrains are made of slotted, PVC pipe
conforming to ASTM D 3034 or equivalent or
corrugated, HDPE pipe conforming to
AASHTO 252M or equivalent.
Slotted underdrains provide greater
intake capacity, clog resistant drainage,
and reduced entrance velocity into the
pipe, thereby reducing the chances of
solids migration.
□
An underdrain cleanout with a minimum 6-
inch diameter and lockable cap is placed every
250 to 300 feet as required based on
underdrain length.
Properly spaced cleanouts will facilitate
underdrain maintenance.
□
Overflow is safely conveyed to a downstream
storm drain system or discharge point. Size
overflow structure to pass 100-year peak flow
for on-line infiltration basins and water quality
peak flow for off-line basins.
Planning for overflow lessens the risk of
property damage due to flooding.
PR-1 Biofiltration with Partial Retention
E-101 Sept. 2021
Nutrient Sensitive Media Design
To design biofiltration with partial retention with underdrain for storm water pollutant control only
(no flow control required), the following steps should be taken:
Conceptual Design and Sizing Approach for Storm Water Pollutant Control Only
To design biofiltration with partial retention and an underdrain for storm water pollutant control only
(no flow control required), the following steps should be taken:
1. Verify that siting and design criteria have been met, including placement requirements,
contributing tributary area, maximum side and finish grade slopes, and the recommended
media surface area tributary ratio.
2. Calculate the DCV per Appendix B based on expected site design runoff for tributary areas.
3. Generalized sizing procedure is presented in Appendix B.3. The surface ponding should be
verified to have a maximum 24-hour drawdown time.
Conceptual Design and Sizing Approach when Storm Water Flow Control is Applicable
Control of flow rates and/or durations will typically require significant surface ponding and/or
aggregate storage volumes, and therefore the following steps should be taken prior to determination
of storm water pollutant control design. Pre-development and allowable post-project flow rates and
durations should be determined as discussed in Chapter 6 of this manual.
1. Verify that siting and design criteria have been met, including placement requirements,
contributing tributary area, maximum side and finish grade slopes, and the recommended
media surface area tributary ratio.
2. Iteratively determine the facility footprint area, surface ponding and/or aggregate storage layer
depth required to provide detention and/or infiltration storage to reduce flow rates and
durations to allowable limits. Flow rates and durations can be controlled from detention
storage by altering outlet structure orifice size(s) and/or water control levels. Multi-level
orifices can be used within an outlet structure to control the full range of flows.
3. If biofiltration with partial retention cannot fully provide the flow rate and duration control
required by this manual, an upstream or downstream structure with significant storage volume
such as an underground vault can be used to provide remaining controls.
4. After biofiltration with partial retention has been designed to meet flow control
requirements, calculations must be completed to verify if storm water pollutant control
requirements to treat the DCV have been met.
Maintenance Overview
Normal Expected Maintenance. Biofiltration with partial retention requires routine maintenance
to: remove accumulated materials such as sediment, trash or debris; maintain vegetation health;
maintain infiltration capacity of the media layer; replenish mulch; and maintain integrity of side slopes,
PR-1 Biofiltration with Partial Retention
E-102 Sept. 2021
inlets, energy dissipators, and outlets. A summary table of standard inspection and maintenance
indicators is provided within this Fact Sheet.
Non-Standard Maintenance or BMP Failure. If any of the following scenarios are observed, the
BMP is not performing as intended to protect downstream waterways from pollution and/or erosion.
Corrective maintenance, increased inspection and maintenance, BMP replacement, or a different BMP
type will be required.
• The BMP is not drained between storm events. Surface ponding longer than approximately
24 hours following a storm event may be detrimental to vegetation health, and surface ponding
longer than approximately 96 hours following a storm event poses a risk of vector (mosquito)
breeding. Poor drainage can result from clogging of the media layer, filter course, aggregate
storage layer, underdrain, or outlet structure. The specific cause of the drainage issue must be
determined and corrected.
• Sediment, trash, or debris accumulation greater than 25% of the surface ponding volume
within one month. This means the load from the tributary drainage area is too high, reducing
BMP function or clogging the BMP. This would require pretreatment measures within the
tributary area draining to the BMP to intercept the materials. Pretreatment components,
especially for sediment, will extend the life of components that are more expensive to replace
such as media, filter course, and aggregate layers.
• Erosion due to concentrated storm water runoff flow that is not readily corrected by adding
erosion control blankets, adding stone at flow entry points, or minor re-grading to restore
proper drainage according to the original plan. 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.
Other Special Considerations. Biofiltration with partial retention is a vegetated structural BMP.
Vegetated structural BMPs that are constructed in the vicinity of, or connected to, an existing
jurisdictional water or wetland could inadvertently result in creation of expanded waters or wetlands.
As such, vegetated structural BMPs have the potential to come under the jurisdiction of the United
States Army Corps of Engineers, SDRWQCB, California Department of Fish and Wildlife, or the
United States Fish and Wildlife Service. This could result in the need for specific resource agency
permits and costly mitigation to perform maintenance of the structural BMP. Along with proper
placement of a structural BMP, routine maintenance is key to preventing this scenario.
SD-A Tree Well
E-3 Sept. 2021
SD-A Tree Well
(Source: County of San Diego LID Manual – EOA, Inc.)
Description
Trees planted to intercept rainfall and runoff as described in this fact sheet may be used as storm water
management measures to provide runoff reduction of the DCV per Appendix B.1.4. Additional
benefits associated with tree wells, include energy conservation, air quality improvement, and aesthetic
enhancement. Tree wells located in the City’s Right-of-Way are subject to the discretion of City
Engineer and Parks and Recreation Director. Typical storm water management benefits associated
with trees include:
• Treatment of storm water – Storm water from impervious area should be directed to the
tree wells. Trees provide treatment through uptake of nutrients and other storm water
pollutants (phytoremediation) and support of other biological processes that break down
pollutants
• Interception of rainfall – tree surfaces (roots, foliage, bark, and branches) intercept,
evaporate, store, or convey precipitation to the soil before it reaches surrounding impervious
surfaces
• Reduced erosion – trees protect denuded area by intercepting or reducing the velocity of rain
drops as they fall through the tree canopy
• Increased infiltration – soil conditions created by roots and fallen leaves promote infiltration
MS4 Permit Category
Site Design
Retention
Manual Category
Site Design
Infiltration
Applicable Performance
Standard
Site Design
Pollutant Control
Flow Control
Primary Benefits
Volume Reduction
E.1
SD-A Tree Well
E-4 Sept. 2021
Typical tree well system components include:
• Directing runoff from
impervious areas through a
drainage opening into a tree well
planting area.
• Trees of the appropriate species
for site conditions and
constraints. Refer to the Plant
List fact sheet (Appendix E.21).
• Available soil media reservoir
volume based on mature tree size,
soil type, water availability,
surrounding land uses, and
project goals
• Optional suspended pavement
design to provide structural
support for adjacent pavement
without requiring compaction of underlying layers
• Optional root barrier devices as needed; a root barrier is a device installed in the ground,
between a tree and the sidewalk or other structures, intended to guide roots down and away
from the sidewalk or structures in order to prevent damage from tree roots.
• Optional tree grates; to be considered to maximize available space for pedestrian circulation
and to protect tree roots from compaction related to pedestrian circulation; tree grates are
typically made up of porous material that will allow the runoff to soak through.
• Optional shallow surface depression for ponding of excess runoff
• Optional planter box underdrain
Design Adaptations for Project Goals
Site design BMP to provide incidental treatment. Tree wells primarily functions as site design
BMPs for incidental treatment.
Storm water pollutant control BMP to provide treatment. Project proponents are allowed to
design tree wells to reduce the volume of stormwater runoff that requires treatment, (the Design
Capture Volume [DCV]), or completely fulfill the pollutant control BMP requirements by retaining
the entire DCV. Benefits from tree wells are accounted for by using the volume reduction values in
Table B.1-3 presented in Appendix B. This credit can apply to other trees that are used for landscaping
purposes that meet the same criteria. Project proponents are required to provide calculations
supporting the amount of credit claimed from implementing trees within the project footprint. Tree
wells designed to completely fulfill the pollutant control BMP requirements by retaining the entire
Schematic of Tree Well
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SD-A Tree Well
E-5 Sept. 2021
DCV are designated as SSD-BMPs and located in Appendix I.
Flow Control BMP to meet hydromodification requirements. Project proponents are also allowed
to design tree wells as a flow control BMP. Benefits from tree wells are accounted for by using the
DCV multipliers listed in Appendix I. Project proponents are required to provide calculations showing
that the entire DCV including the DCV multiplier is retained.
Design Criteria and Considerations
Tree Wells, whether designed as Site Design BMPs, as Stormwater Pollutant Control BMP, or as a
Flow Control BMP must meet the following design criteria and considerations, and if placed in the
right-of-way must be consistent with the County of San Diego Green Streets Standard Drawings.
Deviations from the below criteria may be approved at the discretion of the City Engineer if it is
determined to be appropriate:
Siting and Design Intent/Rationale
□
Tree species is appropriately chosen for the
development (private or public). For public
rights-of-ways, city planning guidelines and
zoning provisions for the permissible species
and placement of trees are consulted. A list of
trees appropriate for site design are provided in
Appendix E.21
Proper tree placement and species
selection minimizes problems such as
pavement damage by surface roots and
poor growth.
□ Tree well placement: ensure area is graded;
and the well is located so that full amount of
DCV reduction drains to well.
Minimizes short-circuiting of run off and
assures DCV reductions are retained
onsite.
□
Location of trees planted along public streets
follows city requirements and guidelines.
Vehicle and pedestrian line of sight are
considered in tree selection and placement.
Location of trees planted within private
development follows city landscape guidelines.
Building setbacks, utility alignments, vehicle
and pedestrian line of sight are considered in
tree selection and placement.
Unless otherwise approved by the City
Engineer the following minimum tree
separation distance is followed
Roadway safety for both vehicular and
pedestrian traffic is a key consideration
for placement along public streets.
SD-A Tree Well
E-6 Sept. 2021
Siting and Design Intent/Rationale
Improvement
Minimum
distance to
Tree Well
Traffic Signal, Stop sign 20 feet
Underground Utility lines
(except sewer) 5 feet
Sewer Lines 10 feet
Above ground utility
structures (Transformers,
Hydrants, Utility poles, etc.)
10 feet
Driveways 10 feet
Intersections (intersecting
curb lines of two streets) 25 feet
□
Underground utilities and overhead wires
are considered in the design and avoided or
circumvented. Underground utilities are routed
around or through the planter in suspended
pavement applications. All underground
utilities are protected from water and root
penetration.
Tree growth can damage utilities and
overhead wires resulting in service
interruptions. Protecting utilities routed
through the planter prevents damage and
service interruptions.
□
Suspended pavement is used for confined
Tree Well soil volume. Suspended pavement
design was developed where appropriate to
minimize soil compaction and improve
infiltration and filtration capabilities.
Suspended pavement was constructed with an
approved structural cell.
Suspended pavement designs provide
structural support without compaction
of the underlying layers, thereby
promoting tree growth.
Recommended structural cells include
poured in place concrete columns, Silva
Cells manufactured by Deeproot Green
Infrastructures and Stratacell and
Stratavault systems manufactured by
Citygreen Systems or approved equal.
Suspended pavement shall not be used
within the city’s right-of-way and
easements.
□ A minimum soil volume of 2 cubic feet per
square foot of canopy projection volume is
provided for each tree. Canopy projection area
The minimum soil volume ensures that
there is adequate storage volume to
allow for unrestricted evapotranspiration
and infiltration.
SD-A Tree Well
E-7 Sept. 2021
Siting and Design Intent/Rationale
is the ground area beneath the tree, measured at
the drip line. Soil volume must be within 1.5
times the mature tree canopy radius. Soil depth
shall be a minimum of 30 inches deep,
preferably 36 inches deep. When placing tree
well next to curbs or other structures use
Structural Soil as outlined in the section below
titled “Confined Tree Well Soil Volume”. Use
Amended Soil per Fact Sheet SD-F in all other
cases.
□ DCV from the tributary area draining to the
tree is equal to or greater than the tree credit
volume
The minimum tributary area ensures that
the tree receives enough runoff to fully
utilize the infiltration and
evapotranspiration potential provided. In
cases where the minimum tributary area
is not provided, the tree credit volume
must be reduced proportionately to the
actual tributary area.
□
Inlet opening to the tree that is at least 18
inches wide.
A minimum 2 inch drop in grade from the inlet
to the finish grade of the tree.
Grated inlets are allowed for pedestrian
circulation. Grates need to be ADA compliant
and have sufficient slip resistance.
Design requirement to ensure that the
runoff from the tributary area is not
bypassed.
Different inlet openings and drops in
grade may be allowed at the discretion of
the City Engineer if calculations are
shown that the diversion flow rate
(Appendix B.4.4) from the tributary area
can be conveyed to the tree. In cases
where the inlet capacity is limiting the
amount of runoff draining to the tree,
the tree credit volume must be reduced
proportionately.
Conceptual Design and Sizing Approach for Site Design
Determine the areas where tree wells can be used in the site design to achieve incidental treatment.
Tree wells reduce runoff volumes from the site. Refer to Appendix B.1. Document the proposed tree
locations in the SWQMP.
For conceptual design and sizing approach for pollutant control and flow control, refer to Appendix
I.
SD-A Tree Well
E-8 Sept. 2021
Tree Planting Design in New or Reconstructed Streetscapes
1. Maximized open soil area for tree planting is the most cost effective method of achieving
the required soil volume.
2. Tree wells within sidewalks shall have a minimum open area of four feet wide by six feet
long. Larger areas may be required to accommodate large root balls.
3. Tree well soil characteristics shall meet the requirements of SD-F Amended Soil.
Structural Requirements for Confined Tree Well Soil Volume
In order to provide adequate soil volume for tree wells, soils may be placed confined beneath adjacent
paved surfaces. Acceptable soil systems capable of carrying D-50 loading include structural soils,
structural slabs, and structural cells:
1. Structural soil systems include CU-StructuralSoilTM, Stalite Structural Soil, or equivalent.
2. Suspended pavements that allow uncompacted growing soil beneath the sidewalk include;
structural slabs that span between structural supports, structural cells, and other
commercially available structural systems. Manufacturer details and certification must be
provided for commercial systems. Structural calculations and details must be provided for
structural slab installations. Structural cells are commercially-available structural systems
placed subsurface that support the sidewalk and are filled with amended soil (SD-F).
Manufacturer details and certification must be provided for commercial systems.
Suspended pavement shall not be used within the city’s right-of-way and easements.
Stormwater Retention and Treatment Volume
Tree wells with expanded soil volume will serve as a method of capturing and retaining the required
volume of stormwater in accordance with City requirements in Appendix B of this manual. These
facilities can be designed to meet the City requirements when surface ponding volume is provided,
whether designed as an enclosed plant bed with covered soil volume, or a continuous open area (either
mulched or with turf) with soil volume under the adjacent sidewalk.
Maintenance Overview
Normal Expected Maintenance. Tree health shall be maintained as part of normal landscape
maintenance. Additionally, ensure that storm water runoff can be conveyed into the tree well as
designed. That is, the opening that allows storm water runoff to flow into the tree well (e.g., a curb
opening, tree grate, or surface depression) shall not be blocked, filled, re-graded, or otherwise changed
in a manner that prevents storm water from draining into the tree well. A summary table of standard
inspection and maintenance indicators is provided within this Fact Sheet.
Non-Standard Maintenance or BMP Failure. Trees wells are site design BMPs that normally do
not require maintenance actions beyond routine landscape maintenance. The normal expected
SD-A Tree Well
E-9 Sept. 2021
maintenance described above ensures the BMP functionality. If changes have been made to the tree
well entrance / opening such that runoff is prevented from draining into the tree well (e.g., a curb
inlet opening is blocked by debris or a grate is clogged causing runoff to flow around instead of into
the tree well, or a surface depression has been filled so runoff flows away from the tree well), the BMP
is not performing as intended to protect downstream waterways from pollution and/or erosion.
Corrective maintenance will be required to restore drainage into the tree well as designed.
Surface ponding of runoff directed into tree wells is expected to infiltrate/evapotranspire within 24-
96 hours following a storm event. Surface ponding longer than approximately 24 hours following a
storm event may be detrimental to vegetation health, and surface ponding longer than approximately
96 hours following a storm event poses a risk of vector (mosquito) breeding. Poor drainage can result
from clogging or compaction of the soils surrounding the tree. Loosen or replace the soils to restore
drainage.
Other Special Considerations. Site design BMPs, such as tree wells, installed within a new
development or redevelopment project are components of an overall storm water management
strategy for the project. The presence of site design BMPs within a project is usually a factor in the
determination of the amount of runoff to be managed with structural BMPs (i.e., the amount of runoff
expected to reach downstream retention or biofiltration basins that process storm water runoff from
the project as a whole). When site design BMPs are not maintained or are removed, this can lead to
clogging or failure of downstream structural BMPs due to greater delivery of runoff and pollutants
than intended for the structural BMP. Therefore, the City Engineer may require confirmation of
maintenance of site design BMPs as part of their structural BMP maintenance documentation
requirements. Site design BMPs that have been installed as part of the project should not be removed,
nor should they be bypassed by re-routing roof drains or re-grading surfaces within the project. If
changes are necessary, consult the City Engineer to determine requirements.
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
Sequence
Contents Checklist
Attachment 2a Hydromodification Management
Exhibit (Required)
✓ Included
Attachment 2b Management of Critical Coarse
Sediment Yield Areas (WMAA Exhibit
is required, additional analyses are
optional)
See Section 6.2 of the BMP Design
Manual.
✓ Exhibit showing project drainage
boundaries marked on WMAA
Critical Coarse Sediment Yield
Area Map (Required)
Optional analyses for Critical Coarse
Sediment Yield Area Determination
6.2.1 Verification of Geomorphic
Landscape Units Onsite
6.2.2 Downstream Systems
Sensitivity to Coarse Sediment
6.2.3 Optional Additional Analysis
of Potential Critical Coarse
Sediment Yield Areas Onsite
Attachment 2c Geomorphic Assessment of Receiving
Channels (Optional)
See Section 6.3.4 of the BMP Design
Manual.
✓ Not performed
Included
Attachment 2d Flow Control Facility Design and
Structural BMP Drawdown
Calculations (Required)
See Chapter 6 and Appendix G of the
BMP Design Manual
✓ Included
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)
HYDROMODIFICATION MANAGEMENT EXHIBIT LEGEND
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SOIL TYPE INFORMATION
SOIL: TYPE B HYDROLOGIC SOILS PER WEB SOIL SURVEY APPLICATION
AVAILABLE THROUGH UNITED STATES DEPARTMENT OF AGRICULTURE
COARSE SEDIMENT YIELD
NO CR/11CAL COARSE SEDIMENT YIELD AREAS TO BE PROTECTED.
REFER TO PRIORITY DEVELOPMENT PROJECT SJM:lMP PREPARED
BY PASCO, LARET, SU/TER&ASSOCIATES
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STRUCTURE WI ORIFICE PLATE
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DRAIN PIPE; 82.5 IE OUT
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GRAVEL
IMPERMEABLE LINER
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BETWEEN BASIN BOTTOM AND NATIVE
MATERIAL SELECTIVELY GRADED PER
GEOTECH RECOMMENDATION TO PROVIDE
RELIABLE INFILTRATION PROPERTIES
TYPICAL DETAIL-BMP-1 BIOFILTRATION BASIN
'B/OFILTRATION "ENGINEERED SOIL"
LAYER SHALL BE MINIMUM 18" DEEP
PER CITY OF CARLSBAD BMP MANUAL
APPENDIX F.3-BIORETENTION SOIL
MEDIA (BSM) SPECIF/CATION
6"
6" FREEBOARD
AND CONVEYANCE
ABOVE RISER
12"PONDING
DEPTH
86.0
36" X 36" BROOKS
BOX;87.0TG
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NOTTO SCALE
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TYPICAL DETAIL-BMP-2 BIOFILTRATION BASIN
NOTTO SCALE
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LAYER SHALL BE MINIMUM 18" DEEP
PER CITY OF CARLSBAD BMP MANUAL
APPENDIX F.3-BIORETENTION SOIL
MEDIA (BSM) SPECIFICATION
HMP EXHIBIT-ATTACHMENT2A
3745ADAMS STREET
CITY OF CARLSBAD
PASCO LARET SUITER
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San Diego I Solana Beach I Orange County
Phone 858.259.82121 www.plsaengineering.com
PLSA 3331,-01
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\ • I _, ~' ' ~ ..... .....
j ITT
1-1---"1 I I
"' I I 't----... $ ill
I I I I
I I I I
) \ I I
0
GRAPHIC SCALE: 1" = 30'
30 60 90
LEGEND
PROPERTY BOUNDARY
CENTERLINE OF ROAD
ADJACENT PROPERTY LINE I
RIGHT-OF-WAY
EXISTING CONTOUR LINE
EXISTING PA1H OF TRAVEL
EXISTING DIRECTION OF FLOW
EXISTING MAJOR DRAINAGE
BASIN BOUNDARY
EXISTING OMA BOUNDARY
EXISTING FLOW LENGTH WITHIN OMA
BOUNDARY
--------
64
PRE-DEVELOPED HMP EXHIBIT
CITY OF CARLSBAD
PASCO LARET SUITER
~ ~~~~ti~'f~~
San Diego I Solana Beach I Orange County
Phone 858.259.82121 www.plsaengineering.com
PLSA 3339-01
POTENTIAL CCSYA EXHIBIT PASCO LAREY SUITER
3745 ADAMS STREET 1----lll&ASSOCIATES
CARLSBAD, CA CIVIL ENGINEERING + LAND PLANNING + LAND SURVEYING
PROJECT NUMBER: PLSA 3339 535 North Highway 101, Ste A, Solana Beach, CA 92075
SCALE: NTS ph 858.259.8212 I b: 858.259.4812 I pl■aengineering.com DATE: APRIL 28, 2020
22
11
88
1616
101044
2525
2727
2323
2222
99
55
1212
1515
1414
33
2424
66
2626
1313
2121
2020
77
1717
1818 1919
1111
RedMountainReservoir
LAKEHENSHAWTURNERLAKE
LAKEWOHLFORD
BUENAVISTALAGOON DIXONRESERVOIR
AQUAHEDIONDALAGOON SAN MARCOSLAKE SUTHERLANDRESERVOIRBATIQUITOSLAGOON
SANDIEGUITORESERVOIR RESERVOIR
LAKEPOWAY
SAN ELIJOLAGOON
EL CAPITANRESERVOIR
SAN VICENTERESERVOIR
MIRAMARRESERVOIR SANTEERECREATIONALLAKES
MISSIONBAY
LOVELANDRESERVOIRLAKEMURRAYMOUNTHELIXLAKE
SAN DIEGOBAY
CHOLLASHEIGHTSRESERVOIR HANSENRESERVOIR
MORENARESERVOIRSWEETWATERRESERVOIRBARRETTLAKE
LOWER OTAYRESERVOIOR
LOSPENASQUITOSLAGOON
LAKERAMONA
UPPER OTAYRESERVOIR
SANDIEGUITOLAGOON
LAKEHODGES
SAN VICENTERESERVOIR
LAKE LINDO
CARLSBADCARLSBAD
CHULACHULAVISTAVISTA
EL CAJONEL CAJON
LA MESALA MESA
NATIONALNATIONALCITYCITY
OCEANSIDEOCEANSIDE
POWAYPOWAY
S.D.S.D.COUNTYCOUNTY
S.D.S.D.COUNTYCOUNTY
SANSANDIEGODIEGO
SANSANMARCOSMARCOS
SANTEESANTEE
VISTAVISTA
San D iegoR iv erChollasC reekSanDiegu itoRiverSanMarcosCreek
Rattles n ak eCreekDulzuraCreekSanMarcosCreek
E scondidoCreekTijuanaR i ver JamulCr e ekSycamoreCreek
C o ttonwood CreekB u ena V is taCre e k
Poway Cr ee k
O tay R i v er
Ca rrol C a nyon
Lusardi Cr e ek
Los Pen asquit o s C r eekEn
cinita s Cree kWoodglenVistaCreekA gua Hedionda Cre ekSantaMargaritaRiverSweetwa terRiverRoseC reek Sa n L u isR e yRive
rO tayR i v erSanta Ysa be lC ree kPotential Critical Coarse Sediment Yield Areas
Exhibit Date: Sept. 8, 2014Regional San Diego County Watersheds
Aerial Imagery Source: DigitalGlobe, 06/2012
Legend
Regional WMAA Streams
Watershed Boundaries
Municipal Boundaries
Rivers & Streams
Potential Critical Coarse Sediment Yield Areas
NORTH
0 5 10 15Miles
REACH ID NAME
1 Santa Margarita River
2 San Luis Rey River
3 Buena Vista Creek
4 Agua Hedionda Creek
5 San Marcos Creek
6 Encinitas Creek
7 Cottonwood Creek (Carlsbad WMA)
8 Escondido Creek
9 San Dieguito Creek - Reach 1
10 San Dieguito Creek - Reach 2
11 Lusardi Creek
12 Los Penasquitos / Poway Creek
13 Rattlesnake Creek
14 Carroll Canyon Creek
15 Rose Creek
16 San Diego River
17 Sycamore Creek
18 Woodglen Vista Creek
19 San Vicente Creek
20 Forester Creek
21 Chollas Creek
22 Sweetwater River - Reach 1
23 Sweetwater River - Reach 2
24 Otay River
25 Jamul / Dulzura Creek
26 Tijuana River
27 Cottonwood Creek (Tijuana WMA)
~ )
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Geosyntec C> RICK 0
consultants E NGJNEERJNG C OMPANY
Surface Volume Drawdown Calculation for BMP-1
Project Name 3745 Adams St
Project No 3339
Surface Drawdown Time: 17.6 hr
Surface Area 700 sq ft
Surface Volume (See Calc Below)1375 cu ft
Underdrain Orifice Diameter: in 0.5 in
C:0.6
Surface Ponding (to invert of lowest
surface discharge opening in outlet
structure):
1.5 ft
Amended Soil Depth: 1.5 ft
Permavoid Depth: 1.5 ft
Orifice Q =0.014 cfs
Effective Depth 38.7 in
Infiltration controlled by orifice 0.857 in/hr
Infiltration underlying soil (Design)0.480 in/hr
Q soil 0.008 cfs
Total Qout 0.022 cfs
*See note below*
*Per City of Carlsbad BMP Design Manual, Biofiltration with Partial
Retention (PR-1) Fact Sheet, surface ponding greater than 12" may be
allowed if: safety issues are considered. 18" ponding widely accepted as
maximum before fencing is needed, 18" ponding proposed.
BMP Surfaoe• Volume Stag,e Storgage-BMP 1
BMP St age~St or.age -Soil V olume
St age Tot al Basin A.re.a El evat ion (s,q-ft) Volume Volume
(cu-It) (cu-ft)
85.50 700 0 0 *Basin FG
85.75, 771.875 184.0 184.0
86.00 843.75 2.0 2..0 3.85.9
86.25 915.62.5 2.19.9 605.9
86.50 987.5 2.37.9 843.8
86.75 1059.375, 2.5S.'9 109·9'.6
87.00 1131.2.5, 2.73.,8 13 73.4 *Surf.ace Ponding
87.2.5, 12.03 .12.5, 2.9'1.8 l i66S.2.
87.50 12.75 3091.B 19175.0
Surface Volume Drawdown Calculation for BMP-2
Project Name 3745 Adams St
Project No 3339
Surface Drawdown Time: 9.8 hr
Surface Area 275 sq ft
Surface Volume (See Calc Below)405 cu ft
Underdrain Orifice Diameter: in 0.4 in
C:0.6
Surface Ponding (to invert of lowest
surface discharge opening in outlet
structure):
1
ft
Amended Soil Depth: 1.5 ft
Permavoid Depth: 1.5 ft
Orifice Q =0.008 cfs
Effective Depth 32.7 in
Infiltration controlled by orifice 1.317 in/hr
Infiltration underlying soil (Design)0.480 in/hr
Q soil 0.003 cfs
Total Qout 0.011 cfs
B-MP Surfaue Volume Stage•-Storage-BMP ~
St age Total Basin Area Elevation Volume Volume (s,q-ft) (cu-ft) (cu-ft)
85.50 2.75.0 0 0 *Basin FG
85.60 301.0 2.8.8 2.8.8
85.70 32.7.0 31.4 60.2.
85.80 353.0 34.0 94.2.
85.90 379.0 36.6 130.8
86.00 405.0 39.2. 17i0.0
86.10 431.0 41.8 2.11.8
86.2.0 457.0 44.4 2.56.2.
86.30 483.0 47.0 303.2.
86.40 509.0 49.6 352..8
86.50 535.0 52..2. 405,.0 *Surface Ponding
86.6:0 561.0 54.8 459.8
86.70 587.0 57.4 517.2.
86.80 613.0 60.0 577.2.
86.90 639.0 62.6 63'9.8
87.00 665.0 65.2. 705,.0
Total Volume Drawdown Calculation for BMP-1
Project Name 3745 Adams St
Project No 3339
Total Drawdown Time: 34.0 hr
Surface Area 700 sq ft
Surface Volume (See Calc Below)2655 cu ft
Underdrain Orifice Diameter: in 0.5 in
C:0.6
Surface Ponding (to invert of lowest
surface discharge opening in outlet
structure):
1.5 ft
Amended Soil Depth: 1.5 ft
Permavoid Depth: 1.5 ft
Orifice Q =0.014 cfs
Effective Depth 38.7 in
Infiltration controlled by orifice 0.857 in/hr
Infiltration underlying soil (Design)0.480 in/hr
Q soil 0.008 cfs
Total Qout 0.022 cfs
Surface Volume = 1,375 CF
Soil Volume = ~1,280 CF (see below)
BMP Soil Volume Stage, Storgage-BMP 1
BMP S age-Storage -Soil Volume
St age To al Basi11 Area Elevatio11 Volume Volume (sq-ft) (cu-ft) (,cu-ft)
82.25 700 0 0 *Bot Basi11
82.50 700 166.3 166.3
82.75 700 166.3 332.5
83.00 700 166.3 4918.8
83.25, 700 166.3 665.0
83.50 700 166.3 831.3
83.75 700 166.3 99•7.5 *Top Permavoid
84.00 700 70.0 1067.5 *Top Pea Gravel
84.25 700 35.0 1102.5
84.50 700 35.0 1137.5
84.75 700 35.0 1172.5
85.00 700 35.0 1207.5
85.25, 700 35.0 12.42.5
85.50 700 35.0 1277.5 *Basi11 FG
Total Volume Drawdown Calculation for BMP-2
Project Name 3745 Adams St
Project No 3339
Total Drawdown Time: 22.0 hr
Surface Area 275 sq ft
Surface Volume (See Calc Below)905 cu ft
Underdrain Orifice Diameter: in 0.4 in
C:0.6
Surface Ponding (to invert of lowest
surface discharge opening in outlet
structure):
1
ft
Amended Soil Depth: 1.5 ft
Permavoid Depth: 1.5 ft
Orifice Q =0.008 cfs
Effective Depth 32.7 in
Infiltration controlled by orifice 1.317 in/hr
Infiltration underlying soil (Design)0.480 in/hr
Q soil 0.003 cfs
Total Qout 0.011 cfs
Surface Volume = 405 CF
Soil Volume = ~500 CF (see below)
BMP Soil Volume Stage,-Storage-BMP 2
St age Total Bas.in Area Elevation (s,q-ft) Volum e Volume
(,cu-ft) (,cu-It)
82..75 2.75.0 0 0 *Bot Bas.in
83.00 275.0 65.3 65.3
83.25 2.75.0 65.3 130.6
83.50 2.75.0 65 .3 1915.9
83.75 2.75.0 65.3 2!61.3
84.00 2.75.0 65.3 32.!6.6
84.2.5 2.75.0 65 .3 391.9 *Top Perm avoid
84.50 2.75.0 2.7.5 419.4 *Top Pea Gravel
84.75 2.75.0 13.8 433.1
85.00 2.75.0 13.8 446.9
85.2.5 2.75.0 13.8 460.6
85.50 2.75.0 13.8 474.4
85.75 2.75.0 13.8 488.1
86.00 2.75.0 13.8 501.9 *Bas.in FG
ATTACHMENT 2d
Storm Water Management Model (SWMM) Supporting Materials
3339 3745 Adams St
1/4/2022
SWMM MODEL SCHEMATICS
PRE-PROJECT MODEL POST-PROJECT MODEL
J:\Active Jobs\3339 3745 ADAMS STREET\CIVIL\REPORTS\SWQMP\Discretionary\SWMM\Output\3339_SWMM_Schematics.xlsx
' ' ' ' ' ' '
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3339 3745 Adams Street
1/4/2022
DMA Area (ac)
Width
(Area/Flow
Length) (ft)% Slope
%
Impervious % "B" Soils
% "C"
Soils
Weighted
Conductivity
(in/hr):
Weighted
Suction
Head (in):
Weighted
Initial
Deficit:N-perv
1 0.195 97 6.0%0%100%0%0.200 3.000 0.320 0.08
2 0.38 169 27.0%0%100%0%0.200 3.000 0.320 0.08
3 0.39 168 2.0%0%100%0%0.200 3.000 0.320 0.08
Total:0.97
DMA Area (ac)
Width
(Area/Flow
Length) (ft)
%
Impervious % Slope % "B" Soils
% "C"
Soils
Weighted
Conductivity
(in/hr):
Weighted
Suction
Head (in):
Weighted
Initial
Deficit:N-perv
1 0.637 677 56%2.5%100%0%0.200 3.000 0.320 0.06
5 0.098 388 0%50.0%100%0%0.200 3.000 0.320 0.08
BMP-1 0.01607 25 0%0.0%100%0%0.200 3.000 0.320 0.06
2 0.213 238 49%1.5%100%0%0.200 3.000 0.320 0.06
BMP-2 0.00631 21 0%0.0%100%0%0.200 3.000 0.320 0.06
Total:0.97
B:0.2 in/hr B:3 in B:0.32
Suction Head:Initial DeficitConductivity:
POC-1
PRE-PROJECT
POST-PROJECT
J:\ACTIVE JOBS\3339 3745 ADAMS STREET\CIVIL\REPORTS\SWQMP\Final Engineering\SWMM\3339_SWMM_Input Alt 7.xlsx
POC-1
[TITLE]
;;Project Title/Notes
3339 3745 Adams Street
Pre-Project Condition
[OPTIONS]
;;Option Value
FLOW_UNITS CFS
INFILTRATION GREEN_AMPT
FLOW_ROUTING KINWAVE
LINK_OFFSETS DEPTH
MIN_SLOPE 0
ALLOW_PONDING NO
SKIP_STEADY_STATE NO
START_DATE 08/28/1951
START_TIME 05:00:00
REPORT_START_DATE 08/28/1951
REPORT_START_TIME 05:00:00
END_DATE 05/23/2008
END_TIME 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
RULE_STEP 00:00:00
INERTIAL_DAMPING PARTIAL
NORMAL_FLOW_LIMITED BOTH
FORCE_MAIN_EQUATION H-W
VARIABLE_STEP 0.75
LENGTHENING_STEP 0
MIN_SURFAREA 12.557
MAX_TRIALS 8
HEAD_TOLERANCE 0.005
SYS_FLOW_TOL 5
LAT_FLOW_TOL 5
MINIMUM_STEP 0.5
THREADS 1
[EVAPORATION]
;;Data Source Parameters
;;-------------- ----------------
MONTHLY .06 .08 .11 .15 .17 .19 .19 .18 .15 .11 .08 .06
DRY_ONLY NO
[RAINGAGES]
;;Name Format Interval SCF Source
POC-1
;;-------------- --------- ------ ------ ----------
Oceanside INTENSITY 1:00 1.0 TIMESERIES Oceanside
[SUBCATCHMENTS]
;;Name Rain Gage Outlet Area %Imperv Width %Slope CurbLen SnowPack
;;-------------- ---------------- ---------------- -------- -------- -------- -------- -------- ----------------
DMA-1 Oceanside DMA-3 0.195 0 97 6 0
DMA-2 Oceanside DMA-3 0.38 0 169 27 0
DMA-3 Oceanside POC-1 0.39 0 168 2 0
[SUBAREAS]
;;Subcatchment N-Imperv N-Perv S-Imperv S-Perv PctZero RouteTo PctRouted
;;-------------- ---------- ---------- ---------- ---------- ---------- ---------- ----------
DMA-1 0.012 0.08 0.05 0.1 25 OUTLET
DMA-2 0.012 0.08 0.05 0.1 25 OUTLET
DMA-3 0.012 0.08 0.05 0.1 25 OUTLET
[INFILTRATION]
;;Subcatchment Suction Ksat IMD
;;-------------- ---------- ---------- ----------
DMA-1 3 0.2 .32
DMA-2 3 0.2 .32
DMA-3 3 0.2 .32
[OUTFALLS]
;;Name Elevation Type Stage Data Gated Route To
;;-------------- ---------- ---------- ---------------- -------- ----------------
;Basin 1
POC-1 0 FREE NO
[TIMESERIES]
;;Name Date Time Value
;;-------------- ---------- ---------- ----------
Oceanside FILE "J:\Active Jobs\3339 3745 ADAMS STREET\CIVIL\REPORTS\SWQMP\Discretionary\SWMM\Rainfall\oceanside.dat"
[REPORT]
;;Reporting Options
SUBCATCHMENTS ALL
NODES ALL
LINKS ALL
[TAGS]
[MAP]
DIMENSIONS 0.000 0.000 10000.000 10000.000
Units None
[COORDINATES]
;;Node X-Coord Y-Coord
;;-------------- ------------------ ------------------
POC-1 1000.000 2500.000
POC-1
[VERTICES]
;;Link X-Coord Y-Coord
;;-------------- ------------------ ------------------
[Polygons]
;;Subcatchment X-Coord Y-Coord
;;-------------- ------------------ ------------------
DMA-1 -421.687 5120.482
DMA-2 2409.639 5301.205
DMA-3 943.775 3594.378
[SYMBOLS]
;;Gage X-Coord Y-Coord
;;-------------- ------------------ ------------------
Oceanside 747.985 6731.113
POC-1
[TITLE]
;;Project Title/Notes
3339 3745 Adams Street
Post-Project Condition
[OPTIONS]
;;Option Value
FLOW_UNITS CFS
INFILTRATION GREEN_AMPT
FLOW_ROUTING KINWAVE
LINK_OFFSETS DEPTH
MIN_SLOPE 0
ALLOW_PONDING NO
SKIP_STEADY_STATE NO
START_DATE 08/28/1951
START_TIME 05:00:00
REPORT_START_DATE 08/28/1951
REPORT_START_TIME 05:00:00
END_DATE 05/23/2008
END_TIME 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
RULE_STEP 00:00:00
INERTIAL_DAMPING PARTIAL
NORMAL_FLOW_LIMITED BOTH
FORCE_MAIN_EQUATION H-W
VARIABLE_STEP 0.75
LENGTHENING_STEP 0
MIN_SURFAREA 12.557
MAX_TRIALS 8
HEAD_TOLERANCE 0.005
SYS_FLOW_TOL 5
LAT_FLOW_TOL 5
MINIMUM_STEP 0.5
THREADS 1
[EVAPORATION]
;;Data Source Parameters
;;-------------- ----------------
MONTHLY .06 .08 .11 .15 .17 .19 .19 .18 .15 .11 .08 .06
DRY_ONLY NO
[RAINGAGES]
;;Name Format Interval SCF Source
POC-1
;;-------------- --------- ------ ------ ----------
Oceanside INTENSITY 1:00 1.0 TIMESERIES Oceanside
[SUBCATCHMENTS]
;;Name Rain Gage Outlet Area %Imperv Width %Slope CurbLen SnowPack
;;-------------- ---------------- ---------------- -------- -------- -------- -------- -------- ----------------
DMA-1 Oceanside BMP-1 0.637 56 677 2.5 0
DMA-5 Oceanside POC-1 0.098 0 388 50 0
BMP-1 Oceanside POC-1 0.01607 0 25 0 0
DMA-2 Oceanside BMP-2 0.213 49 238 1.5 0
BMP-2 Oceanside POC-1 0.00631 0 21 0 0
[SUBAREAS]
;;Subcatchment N-Imperv N-Perv S-Imperv S-Perv PctZero RouteTo PctRouted
;;-------------- ---------- ---------- ---------- ---------- ---------- ---------- ----------
DMA-1 0.012 0.06 0.05 0.1 25 OUTLET
DMA-5 0.012 0.08 0.05 0.1 25 OUTLET
BMP-1 0.012 0.06 0.05 0.1 25 OUTLET
DMA-2 0.012 0.06 0.05 0.1 25 OUTLET
BMP-2 0.012 0.06 0.05 0.1 25 OUTLET
[INFILTRATION]
;;Subcatchment Suction Ksat IMD
;;-------------- ---------- ---------- ----------
DMA-1 3 0.2 .32
DMA-5 3 0.2 .32
BMP-1 3 0.2 .32
DMA-2 3 0.2 .32
BMP-2 3 0.2 .32
[LID_CONTROLS]
;;Name Type/Layer Parameters
;;-------------- ---------- ----------
BMP-1 BC
BMP-1 SURFACE 25.03 0 0 0 5
BMP-1 SOIL 18 0.4 0.2 0.1 5 5 1.5
BMP-1 STORAGE 18 0.99 0.705 0
BMP-1 DRAIN 0.1179 0.5 0 6 0 0
BMP-2 BC
BMP-2 SURFACE 16.97 0 0 0 5
BMP-2 SOIL 18 0.4 0.2 0.1 5 5 1.5
BMP-2 STORAGE 18 0.99 .705 0
BMP-2 DRAIN 0.1920 0.5 0 6 0 0
[LID_USAGE]
;;Subcatchment LID Process Number Area Width InitSat FromImp ToPerv RptFile DrainTo
FromPerv
;;-------------- ---------------- ------- ---------- ---------- ---------- ---------- ---------- ------------------------ ------------
---- ----------
POC-1
BMP-1 BMP-1 1 700.01 0 0 100 0 * *
0
BMP-2 BMP-2 1 274.86 0 0 100 0 * *
0
[OUTFALLS]
;;Name Elevation Type Stage Data Gated Route To
;;-------------- ---------- ---------- ---------------- -------- ----------------
;Basin 1
POC-1 0 FREE NO
[TIMESERIES]
;;Name Date Time Value
;;-------------- ---------- ---------- ----------
Oceanside FILE "J:\Active Jobs\3339 3745 ADAMS STREET\CIVIL\REPORTS\SWQMP\Discretionary\SWMM\Rainfall\oceanside.dat"
[REPORT]
;;Reporting Options
SUBCATCHMENTS ALL
NODES ALL
LINKS ALL
[TAGS]
[MAP]
DIMENSIONS 0.000 0.000 10000.000 10000.000
Units None
[COORDINATES]
;;Node X-Coord Y-Coord
;;-------------- ------------------ ------------------
POC-1 426.829 1514.228
[VERTICES]
;;Link X-Coord Y-Coord
;;-------------- ------------------ ------------------
[Polygons]
;;Subcatchment X-Coord Y-Coord
;;-------------- ------------------ ------------------
DMA-1 -873.984 5518.293
DMA-5 2409.639 5301.205
BMP-1 -813.008 4095.528
DMA-2 710.784 5502.451
BMP-2 588.235 4080.882
[SYMBOLS]
;;Gage X-Coord Y-Coord
;;-------------- ------------------ ------------------
Oceanside 747.985 6731.113
SWMM OUTPUT REPORT PRE-PROJECT CONDITION
J:\ACTIVE JOBS\3339 3745 ADAMS STREET\CIVIL\REPORTS\SWQMP\Final Engineering\SWMM\Output\3339_PreProject_SWMM_results.docx
EPA STORM WATER MANAGEMENT MODEL - VERSION 5.1 (Build 5.1.013)
--------------------------------------------------------------
3339 3745 Adams Street
Pre-Project Condition
*********************************************************
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 ............... CFS
Process Models:
Rainfall/Runoff ........ YES
RDII ................... NO
Snowmelt ............... NO
Groundwater ............ NO
Flow Routing ........... NO
Water Quality .......... NO
Infiltration Method ...... GREEN_AMPT
Starting Date ............ 08/28/1951 05:00:00
Ending Date .............. 05/23/2008 23:00:00
Antecedent Dry Days ...... 0.0
Report Time Step ......... 01:00:00
Wet Time Step ............ 00:15:00
Dry Time Step ............ 04:00:00
************************** Volume Depth
Runoff Quantity Continuity acre-feet inches
************************** --------- -------
Total Precipitation ...... 54.288 675.090
Evaporation Loss ......... 0.164 2.039
Infiltration Loss ........ 52.597 654.053
Surface Runoff ........... 1.744 21.693
Final Storage ............ 0.000 0.000
Continuity Error (%) ..... -0.399
************************** Volume Volume
Flow Routing Continuity acre-feet 10^6 gal
************************** --------- ---------
Dry Weather Inflow ....... 0.000 0.000
Wet Weather Inflow ....... 1.744 0.568
Groundwater Inflow ....... 0.000 0.000
RDII Inflow .............. 0.000 0.000
External Inflow .......... 0.000 0.000
External Outflow ......... 1.744 0.568
Flooding Loss ............ 0.000 0.000
SWMM OUTPUT REPORT PRE-PROJECT CONDITION
J:\ACTIVE JOBS\3339 3745 ADAMS STREET\CIVIL\REPORTS\SWQMP\Final Engineering\SWMM\Output\3339_PreProject_SWMM_results.docx
Evaporation Loss ......... 0.000 0.000
Exfiltration Loss ........ 0.000 0.000
Initial Stored Volume .... 0.000 0.000
Final Stored Volume ...... 0.000 0.000
Continuity Error (%) ..... 0.000
***************************
Subcatchment Runoff Summary
***************************
------------------------------------------------------------------------------------------------------------------------------
Total Total Total Total Imperv Perv Total Total Peak Runoff
Precip Runon Evap Infil Runoff Runoff Runoff Runoff Runoff Coeff
Subcatchment in in in in in in in 10^6 gal CFS
------------------------------------------------------------------------------------------------------------------------------
DMA-1 675.09 0.00 1.97 652.56 0.00 23.04 23.04 0.12 0.20 0.034
DMA-2 675.09 0.00 1.95 651.81 0.00 24.35 24.35 0.25 0.38 0.036
DMA-3 675.09 35.25 2.16 656.99 0.00 53.68 53.68 0.57 0.97 0.076
Analysis begun on: Tue Jan 4 08:23:32 2022
Analysis ended on: Tue Jan 4 08:24:09 2022
Total elapsed time: 00:00:37
SWMM OUTPUT REPORT POST-PROJECT CONDITION
J:\ACTIVE JOBS\3339 3745 ADAMS STREET\CIVIL\REPORTS\SWQMP\Final Engineering\SWMM\Output\3339 PostProject SWMM_results.docx
EPA STORM WATER MANAGEMENT MODEL - VERSION 5.1 (Build 5.1.013)
--------------------------------------------------------------
3339 3745 Adams Street
Post-Project Condition
*********************************************************
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 ............... CFS
Process Models:
Rainfall/Runoff ........ YES
RDII ................... NO
Snowmelt ............... NO
Groundwater ............ NO
Flow Routing ........... NO
Water Quality .......... NO
Infiltration Method ...... GREEN_AMPT
Starting Date ............ 08/28/1951 05:00:00
Ending Date .............. 05/23/2008 23:00:00
Antecedent Dry Days ...... 0.0
Report Time Step ......... 01:00:00
Wet Time Step ............ 00:15:00
Dry Time Step ............ 04:00:00
************************** Volume Depth
Runoff Quantity Continuity acre-feet inches
************************** --------- -------
Initial LID Storage ...... 0.003 0.042
Total Precipitation ...... 54.591 675.090
Evaporation Loss ......... 5.510 68.137
Infiltration Loss ........ 41.623 514.720
Surface Runoff ........... 0.701 8.665
LID Drainage ............. 7.334 90.700
Final Storage ............ 0.006 0.079
Continuity Error (%) ..... -1.062
************************** Volume Volume
Flow Routing Continuity acre-feet 10^6 gal
************************** --------- ---------
Dry Weather Inflow ....... 0.000 0.000
Wet Weather Inflow ....... 8.035 2.618
Groundwater Inflow ....... 0.000 0.000
RDII Inflow .............. 0.000 0.000
External Inflow .......... 0.000 0.000
SWMM OUTPUT REPORT POST-PROJECT CONDITION
J:\ACTIVE JOBS\3339 3745 ADAMS STREET\CIVIL\REPORTS\SWQMP\Final Engineering\SWMM\Output\3339 PostProject SWMM_results.docx
External Outflow ......... 8.035 2.618
Flooding Loss ............ 0.000 0.000
Evaporation Loss ......... 0.000 0.000
Exfiltration Loss ........ 0.000 0.000
Initial Stored Volume .... 0.000 0.000
Final Stored Volume ...... 0.000 0.000
Continuity Error (%) ..... 0.000
***************************
Subcatchment Runoff Summary
***************************
------------------------------------------------------------------------------------------------------------------------------
Total Total Total Total Imperv Perv Total Total Peak Runoff
Precip Runon Evap Infil Runoff Runoff Runoff Runoff Runoff Coeff
Subcatchment in in in in in in in 10^6 gal CFS
------------------------------------------------------------------------------------------------------------------------------
DMA-1 675.09 0.00 56.06 286.53 329.30 11.20 340.50 5.89 0.71 0.504
DMA-5 675.09 0.00 1.42 650.22 0.00 26.52 26.52 0.07 0.10 0.039
BMP-1 675.09 13496.96 891.60 8856.10 0.00 0.00 4423.26 1.93 0.72 0.312
DMA-2 675.09 0.00 49.29 332.23 288.08 12.77 300.85 1.74 0.23 0.446
BMP-2 675.09 10155.39 862.42 6363.00 0.00 0.00 3604.02 0.62 0.24 0.333
***********************
LID Performance Summary
***********************
--------------------------------------------------------------------------------------------------------------------
Total Evap Infil Surface Drain Initial Final Continuity
Inflow Loss Loss Outflow Outflow Storage Storage Error
Subcatchment LID Control in in in in in in in %
--------------------------------------------------------------------------------------------------------------------
BMP-1 BMP-1 14172.05 891.63 8856.42 292.29 4131.13 1.80 2.66 -0.00
BMP-2 BMP-2 10830.48 862.46 6363.32 176.35 3427.85 1.80 2.46 -0.00
Analysis begun on: Tue Jan 4 08:31:10 2022
Analysis ended on: Tue Jan 4 08:31:49 2022
Total elapsed time: 00:00:39
POC-1
Peak Flow Frequency Summary
Return Period Pre-project Qpeak
(cfs)
Post-project - Mitigated Q
(cfs)
LF = 0.1xQ2 0.030 0.005
2-year 0.298 0.047
Permavoid Layer 0.477 0.121
10-year 0.620 0.411
J:\ACTIVE JOBS\3339 3745 ADAMS STREET\CIVIL\REPORTS\SWQMP\Final Engineering\SWMM\3339 SWMM_PostProcessing_Alt7.xlsx
0.000
0.100
0.200
0.300
0.400
0.500
0.600
0.700
0 1 2 3 4 5 6 7 8 9 10Peak Flow in cfsReturn Period in Years
POC-1
Peak Flow Frequency Curves
Pre-project Qpeak
Post-project Mitigated Qpeak
Low-flow Threshold:10%POC-1
0.1xQ2 (Pre):0.030 cfs
Q10 (Pre):0.620 cfs
Ordinate #:100
Incremental Q (Pre):0.00590 cfs
Total Hourly Data:497370 hours The proposed BMP:PASSED
Permavoid Layer Pre-project Flow
(cfs)Pre-project Hours Pre-project %
Time Exceeding
Post-project %
Time Exceeding Percentage Pass/Fail
0 0.030 118 2.37E-04 115 2.31E-04 97%Pass
1 0.036 114 2.29E-04 70 1.41E-04 61%Pass
2 0.042 112 2.25E-04 57 1.15E-04 51%Pass
3 0.048 110 2.21E-04 47 9.45E-05 43%Pass
4 0.053 109 2.19E-04 39 7.84E-05 36%Pass
5 0.059 105 2.11E-04 32 6.43E-05 30%Pass
6 0.065 102 2.05E-04 30 6.03E-05 29%Pass
7 0.071 100 2.01E-04 29 5.83E-05 29%Pass
8 0.077 98 1.97E-04 23 4.62E-05 23%Pass
9 0.083 97 1.95E-04 18 3.62E-05 19%Pass
10 0.089 91 1.83E-04 16 3.22E-05 18%Pass
11 0.095 89 1.79E-04 16 3.22E-05 18%Pass
12 0.101 87 1.75E-04 15 3.02E-05 17%Pass
13 0.107 84 1.69E-04 15 3.02E-05 18%Pass
14 0.112 81 1.63E-04 15 3.02E-05 19%Pass
15 0.118 80 1.61E-04 14 2.81E-05 18%Pass
16 0.124 66 1.33E-04 14 2.81E-05 21%Pass
17 0.130 65 1.31E-04 13 2.61E-05 20%Pass
18 0.136 65 1.31E-04 13 2.61E-05 20%Pass
19 0.142 64 1.29E-04 13 2.61E-05 20%Pass
20 0.148 63 1.27E-04 13 2.61E-05 21%Pass
21 0.154 61 1.23E-04 13 2.61E-05 21%Pass
22 0.160 60 1.21E-04 13 2.61E-05 22%Pass
23 0.166 60 1.21E-04 13 2.61E-05 22%Pass
24 0.171 55 1.11E-04 13 2.61E-05 24%Pass
25 0.177 55 1.11E-04 13 2.61E-05 24%Pass
26 0.183 55 1.11E-04 13 2.61E-05 24%Pass
27 0.189 52 1.05E-04 13 2.61E-05 25%Pass
28 0.195 49 9.85E-05 13 2.61E-05 27%Pass
29 0.201 48 9.65E-05 13 2.61E-05 27%Pass
30 0.207 48 9.65E-05 13 2.61E-05 27%Pass
31 0.213 48 9.65E-05 12 2.41E-05 25%Pass
32 0.219 48 9.65E-05 11 2.21E-05 23%Pass
33 0.225 47 9.45E-05 11 2.21E-05 23%Pass
34 0.230 46 9.25E-05 11 2.21E-05 24%Pass
35 0.236 46 9.25E-05 11 2.21E-05 24%Pass
36 0.242 44 8.85E-05 11 2.21E-05 25%Pass
37 0.248 43 8.65E-05 11 2.21E-05 26%Pass
38 0.254 42 8.44E-05 11 2.21E-05 26%Pass
39 0.260 42 8.44E-05 11 2.21E-05 26%Pass
40 0.266 39 7.84E-05 11 2.21E-05 28%Pass
41 0.272 36 7.24E-05 10 2.01E-05 28%Pass
42 0.278 36 7.24E-05 10 2.01E-05 28%Pass
43 0.284 36 7.24E-05 10 2.01E-05 28%Pass
44 0.290 33 6.63E-05 10 2.01E-05 30%Pass
45 0.295 33 6.63E-05 9 1.81E-05 27%Pass
46 0.301 32 6.43E-05 9 1.81E-05 28%Pass
47 0.307 32 6.43E-05 9 1.81E-05 28%Pass
48 0.313 32 6.43E-05 9 1.81E-05 28%Pass
49 0.319 32 6.43E-05 9 1.81E-05 28%Pass
50 0.325 32 6.43E-05 9 1.81E-05 28%Pass
51 0.331 31 6.23E-05 9 1.81E-05 29%Pass
52 0.337 30 6.03E-05 9 1.81E-05 30%Pass
53 0.343 26 5.23E-05 9 1.81E-05 35%Pass
54 0.349 26 5.23E-05 9 1.81E-05 35%Pass
II II
Permavoid Layer Pre-project Flow
(cfs)Pre-project Hours Pre-project %
Time Exceeding
Post-project %
Time Exceeding Percentage Pass/Fail
55 0.354 26 5.23E-05 8 1.61E-05 31%Pass
56 0.360 26 5.23E-05 8 1.61E-05 31%Pass
57 0.366 24 4.83E-05 8 1.61E-05 33%Pass
58 0.372 24 4.83E-05 8 1.61E-05 33%Pass
59 0.378 21 4.22E-05 7 1.41E-05 33%Pass
60 0.384 21 4.22E-05 7 1.41E-05 33%Pass
61 0.390 20 4.02E-05 7 1.41E-05 35%Pass
62 0.396 18 3.62E-05 7 1.41E-05 39%Pass
63 0.402 17 3.42E-05 6 1.21E-05 35%Pass
64 0.408 17 3.42E-05 6 1.21E-05 35%Pass
65 0.413 17 3.42E-05 6 1.21E-05 35%Pass
66 0.419 17 3.42E-05 6 1.21E-05 35%Pass
67 0.425 17 3.42E-05 6 1.21E-05 35%Pass
68 0.431 17 3.42E-05 6 1.21E-05 35%Pass
69 0.437 16 3.22E-05 6 1.21E-05 38%Pass
70 0.443 16 3.22E-05 6 1.21E-05 38%Pass
71 0.449 16 3.22E-05 6 1.21E-05 38%Pass
72 0.455 15 3.02E-05 6 1.21E-05 40%Pass
73 0.461 15 3.02E-05 6 1.21E-05 40%Pass
74 0.467 15 3.02E-05 6 1.21E-05 40%Pass
75 0.472 15 3.02E-05 6 1.21E-05 40%Pass
76 0.478 12 2.41E-05 5 1.01E-05 42%Pass
77 0.484 11 2.21E-05 5 1.01E-05 45%Pass
78 0.490 11 2.21E-05 5 1.01E-05 45%Pass
79 0.496 11 2.21E-05 5 1.01E-05 45%Pass
80 0.502 9 1.81E-05 5 1.01E-05 56%Pass
81 0.508 8 1.61E-05 5 1.01E-05 63%Pass
82 0.514 8 1.61E-05 5 1.01E-05 63%Pass
83 0.520 8 1.61E-05 5 1.01E-05 63%Pass
84 0.526 8 1.61E-05 5 1.01E-05 63%Pass
85 0.532 7 1.41E-05 5 1.01E-05 71%Pass
86 0.537 7 1.41E-05 5 1.01E-05 71%Pass
87 0.543 7 1.41E-05 5 1.01E-05 71%Pass
88 0.549 6 1.21E-05 5 1.01E-05 83%Pass
89 0.555 6 1.21E-05 5 1.01E-05 83%Pass
90 0.561 6 1.21E-05 5 1.01E-05 83%Pass
91 0.567 6 1.21E-05 5 1.01E-05 83%Pass
92 0.573 6 1.21E-05 5 1.01E-05 83%Pass
93 0.579 6 1.21E-05 5 1.01E-05 83%Pass
94 0.585 6 1.21E-05 5 1.01E-05 83%Pass
95 0.591 6 1.21E-05 4 8.04E-06 67%Pass
96 0.596 6 1.21E-05 4 8.04E-06 67%Pass
97 0.602 5 1.01E-05 4 8.04E-06 80%Pass
98 0.608 5 1.01E-05 4 8.04E-06 80%Pass
99 0.614 5 1.01E-05 4 8.04E-06 80%Pass
100 0.620 5 1.01E-05 4 8.04E-06 80%Pass
0.000
0.100
0.200
0.300
0.400
0.500
0.600
0.700
1.0E-06 1.0E-05 1.0E-04 1.0E-03 1.0E-02Flow (cfs)% Time Exceeding
POC-1
Flow Duration Curve
[Pre vs. Post (Mitigated)]
Pre-project Q
Post-project (Mitigated) Q
I 11
l l I I
l~
~I I I
I I I~ ""
11
"I .., a,;
~b
~
--1:r-
I
1 ti
ija
I ~ 11
I
·~
~
~__.. l\ --, L.. ~. \
I I 1 • ~
I I I
--... I
POC-1
BMP-1
PARAMETER ABBREV.
Ponding Depth PD 18.0 in
Bioretention Soil Layer S 18 in
Permavoid Layer G 18 in
4.5 ft
54 in
Orifice Coefficient cg 0.6 --
Low Flow Orifice Diameter D 0.5 in
Drain exponent n 0.5 --
Flow Rate (volumetric)Q 0.014 cfs
Ponding Depth Surface Area APD 1275 ft2
AS, AG 700 ft2
AS, AG 0.0161 ac
Porosity of Bioretention Soil n 1.00 -
Flow Rate (per unit area)q 0.858 in/hr
Effective Ponding Depth PDeff 25.03 in
Flow Coefficient C 0.1179 --
Bio-Retention Cell
LID BMP
Bioretention Surface Area
TOTAL
SWMM Model Flow Coefficient Calculation and
Effective Ponding Depth Calculation
POC-1
BMP-2
PARAMETER ABBREV.
Ponding Depth PD 12 in
Bioretention Soil Layer S 18 in
Permavoid Layer G 18 in
4.0 ft
48 in
Orifice Coefficient cg 0.6 --
Low Flow Orifice Diameter D 0.4 in
Drain exponent n 0.5 --
Flow Rate (volumetric)Q 0.008 cfs
Ponding Depth Surface Area APD 515 ft2
AS, AG 275 ft2
AS, AG 0.0063 ac
Porosity of Bioretention Soil n 1.00 -
Flow Rate (per unit area)q 1.317 in/hr
Effective Ponding Depth PDeff 16.97 in
Flow Coefficient C 0.1920 --
SWMM Model Flow Coefficient Calculation and
Effective Ponding Depth Calculation
Bio-Retention Cell
LID BMP
TOTAL
Bioretention Surface Area
Manning’s n Values for Overland Flow1
The BMP Design Manuals within the County of San Diego allow for a land surface description other than
short prairie grass to be used for hydromodification BMP design only if documentation provided is
consistent with Table A.6 of the SWMM 5 User’s Manual.
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 by providing an in-depth description of the program’s hydrologic components. Table 3-5
of the SWMM Hydrology Reference Manual expounds upon Table A.6 of the SWMM 5 User’s Manual by
providing Manning’s n values for additional overland flow surfaces. 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. The values are
provided in the table below:
Overland Surface Manning value (n)
Smooth asphalt pavement 0.010
Smooth impervious surface 0.011
Tar and sand pavement 0.012
Concrete pavement 0.014
Rough impervious surface 0.015
Smooth bare packed soil 0.017
Moderate bare packed soil 0.025
Rough bare packed soil 0.032
Gravel soil 0.025
Mowed poor grass 0.030
Average grass, closely clipped sod 0.040
Pasture 0.040
Timberland 0.060
Dense grass 0.060
Shrubs and bushes 0.080
Land Use
Business 0.014
Semibusiness 0.022
Industrial 0.020
Dense residential 0.025
Suburban residential 0.030
Parks and lawns 0.040
1Content summarized from Improving Accuracy in Continuous Simulation Modeling: Guidance for
Selecting Pervious Overland Flow Manning’s n Values in the San Diego Region (TRWE, 2016).
N-perv for pre-dev and post-dev
DMA 5 (self-mitigating slope)
N-perv for post-dev DMAs 1 & 2
TORY R. WALKER ENGINEERING
RELIABLE SOLUTIONS IN WATER RESOURCES
WATERSHED, FLOODPLAIN e? STORM WATER MANAGEMENT · RIVER RESTORATION· FLOOD FACILITIES DESIGN· SEDIMENT e? EROSION
122 CIVIC CENTER DRIVE, SUITE 206, VISTA CA 92084 · 760-414-9212 · TRWENGINEERING.COM
Hydrologic Soil Group—San Diego County Area, California
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
4/30/2020
Page 1 of 43668480366849036685003668510366852036685303668540366855036685603668570366858036684803668490366850036685103668520366853036685403668550366856036685703668580468620468630468640468650468660468670468680468690468700468710468720468730468740468750468760468770468780
468620 468630 468640 468650 468660 468670 468680 468690 468700 468710 468720 468730 468740 468750 468760 468770 468780
33° 9' 20'' N 117° 20' 11'' W33° 9' 20'' N117° 20' 5'' W33° 9' 16'' N
117° 20' 11'' W33° 9' 16'' N
117° 20' 5'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 11N WGS84
0 35 70 140 210Feet
0 10 20 40 60Meters
Map Scale: 1:778 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
USDA =
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Rating Polygons
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Lines
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Soil Rating Points
A
A/D
B
B/D
C
C/D
D
Not rated or not available
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: San Diego County Area, California
Survey Area Data: Version 14, Sep 16, 2019
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Jan 23, 2020—Feb
13, 2020
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Hydrologic Soil Group—San Diego County Area, California
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
4/30/2020
Page 2 of 4USDA =
□
D
D
D
D
D
D
D
D
,,..,,,.
,,..,,,.
□
■
■
□
□
,,..._.,
t-+-t
~
tllWI ,..,,.
~
•
Hydrologic Soil Group
Map unit symbol Map unit name Rating Acres in AOI Percent of AOI
MlC Marina loamy coarse
sand, 2 to 9 percent
slopes
B 1.2 100.0%
Totals for Area of Interest 1.2 100.0%
Description
Hydrologic soil groups are based on estimates of runoff potential. Soils are
assigned to one of four groups according to the rate of water infiltration when the
soils are not protected by vegetation, are thoroughly wet, and receive
precipitation from long-duration storms.
The soils in the United States are assigned to four groups (A, B, C, and D) and
three dual classes (A/D, B/D, and C/D). The groups are defined as follows:
Group A. Soils having a high infiltration rate (low runoff potential) when
thoroughly wet. These consist mainly of deep, well drained to excessively
drained sands or gravelly sands. These soils have a high rate of water
transmission.
Group B. Soils having a moderate infiltration rate when thoroughly wet. These
consist chiefly of moderately deep or deep, moderately well drained or well
drained soils that have moderately fine texture to moderately coarse texture.
These soils have a moderate rate of water transmission.
Group C. Soils having a slow infiltration rate when thoroughly wet. These consist
chiefly of soils having a layer that impedes the downward movement of water or
soils of moderately fine texture or fine texture. These soils have a slow rate of
water transmission.
Group D. Soils having a very slow infiltration rate (high runoff potential) when
thoroughly wet. These consist chiefly of clays that have a high shrink-swell
potential, soils that have a high water table, soils that have a claypan or clay
layer at or near the surface, and soils that are shallow over nearly impervious
material. These soils have a very slow rate of water transmission.
If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is
for drained areas and the second is for undrained areas. Only the soils that in
their natural condition are in group D are assigned to dual classes.
Rating Options
Aggregation Method: Dominant Condition
Hydrologic Soil Group—San Diego County Area, California
Natural Resources
Conservation Service
Web Soil Survey
National Cooperative Soil Survey
4/30/2020
Page 3 of 4USDA =
Appendix G: Guidance for Continuous Simulation and Hydromodification Management Sizing
Factors
G-4 Sept. 2021
Zone Map"), prepared by California Department of Water Resources, dated January 2012. The CIMIS
ETo Zone Map is available from www.cimis.gov, and is provided in this Appendix as Figure G.1-2.
Determine the appropriate reference evapotranspiration zone for the project from the CIMIS ETo
Zone Map. The monthly average reference evapotranspiration values are provided below in Table
G.1-1.
Figure G.1-2: California Irrigation Management Information System "Reference Evapotranspiration
Zones"
SITE
SAN BERNARDINO t
9
117/
R
17
V E R S
D I E G 0
16
D E
16
M P E R
18 EL CENTRO
t
18
A L
Appendix G: Guidance for Continuous Simulation and Hydromodification Management Sizing Factors
G-6 February 2016
Table G.1-1: Monthly Average Reference Evapotranspiration by ETo Zone
(inches/month and inches/day) for use in SWMM Models for Hydromodification Management Studies in San Diego County
CIMIS Zones 1, 4, 6, 9, and 16 (See CIMIS ETo Zone Map)
January February March April May June July August September October November December
Zone in/month in/month in/month in/month in/month in/month in/month in/month in/month in/month in/month in/month
1 0.93 1.4 2.48 3.3 4.03 4.5 4.65 4.03 3.3 2.48 1.2 0.62
4 1.86 2.24 3.41 4.5 5.27 5.7 5.89 5.58 4.5 3.41 2.4 1.86
6 1.86 2.24 3.41 4.8 5.58 6.3 6.51 6.2 4.8 3.72 2.4 1.86
9 2.17 2.8 4.03 5.1 5.89 6.6 7.44 6.82 5.7 4.03 2.7 1.86
16 1.55 2.52 4.03 5.7 7.75 8.7 9.3 8.37 6.3 4.34 2.4 1.55
January February March April May June July August September October November December
Days 31 28 31 30 31 30 31 31 30 31 30 31
Zone in/day in/day in/day in/day in/day in/day in/day in/day in/day in/day in/day in/day
1 0.030 0.050 0.080 0.110 0.130 0.150 0.150 0.130 0.110 0.080 0.040 0.020
4 0.060 0.080 0.110 0.150 0.170 0.190 0.190 0.180 0.150 0.110 0.080 0.060
6 0.060 0.080 0.110 0.160 0.180 0.210 0.210 0.200 0.160 0.120 0.080 0.060
9 0.070 0.100 0.130 0.170 0.190 0.220 0.240 0.220 0.190 0.130 0.090 0.060
16 0.050 0.090 0.130 0.190 0.250 0.290 0.300 0.270 0.210 0.140 0.080 0.050
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:
√ 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 store 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
BMP DESCRIPTION
8/0F/L TRA T/ON (975 SF TOTAL)
ATTACHMENT-3a
BMP MAINTENANCE THRESHOLDS
STORM WATER MANAGEMENT AND DISCHARGE CONTROL MAINTENANCE AGREEMENT APPROVAL NO:
O&M RESPONSIBLE PARTY DESIGNEE: ADAMS STREET RESIDENCES HOA
POS~CONSTRUCTTONPERMANENTBMP
OPERATION & MAINTENANCE PROCEDURE DETAILS
MAINTENANCE INDICATORS MAINTENANCE ACTION
ACCUMULATION OF SEDIMENT, LITTER, OR DEBRIS REMOVE AND PROPERLY DISPOSE OF ACCUMULATED MATERIALS, WITHOUT DAMAGE TO THE VEGETATION
POOR VEGETATION ESTABLISHMENT
OVERGROWN VEGETATION
EROSION DUE TO CONCENTRATED /RR/GA TION FLOW
EROSION DUE TO CONCENTRATED STORM WATER RUNOFF FLOW
STANDING WATER IN BIOFILTRATIONAREAS
OBSTRUCTED INLET OR OUTLET STRUCTURE
DAMAGE TO INLET OR OUTLET STRUCTURE
MAINTENANCE EQUIPMENT AND ACCESS
USE LANDSCAPE EQUIPMENT FOR MAINTENANCE; ACCESS BMPS FROM PRIVATE DRIVEWAY ON EASTERN
PORTION OF SITE
INSPECTION FACILITATION
INSTALL 36" X 36" OUTLET RISER STRUCTURE TO SERVE AS CLEANOUT AND PROVIDE
OBSERVATION ACCESS FOR INSPECTION OF MAINTENANCE THRESHOLDS; MARKING TO BE
PROVIDED ON BMP COMPONENTS TO DETERMINE HOW FULL BMP IS.
RE-SEED, RE-PLANT, OR RE-ESTABLISH VEGETATION PER ORIGINAL PLANS
MOW OR TRIM AS APPROPRIATE, BUT NOT LESS THAT THE DESIGN HEIGHT OF THE VEGETATION PER ORIGINAL PLANS.
REPAIR/RE-SEED/RE-PLANT ERODED AREAS AND ADJUST THE /RR/GA TION SYSTEM
REPAIR/RE-SEED/RE-PLANT ERODED AREAS AND MAKE APPROPRIATE CORRECTIVE MEASURES SUCH AS
ADDING STONE AT FLOW ENTRY POINTS OR MINOR RE-GRADING TO RESTORE PROPER DRAINAGE
ACCORDING TO THE ORIGINAL PLAN.
MAKE APPROPRIATE CORRECTIVE MEASURES SUCH AS ADJUSTING IRRIGATION SYSTEM, REMOVING OBSTRUCTION OF
DEBRIS OR INVASIVE VEGETATION, OR CLEANING UNDERDRA/NS
CLEAR OBSTRUCTIONS
REPAIR OR REPLACE AS APPLICABLE
MAINTENANCE FREQUENCY
BIOFIL TRA TION BMP TO BE MAINTAINED ANNUALLY & AS-NEEDED
PASCO LAREY SUITER
& ASSOCIATES
CIVIL ENIINEERINI + LAND Pl.ANNIN& + LAND a,RVEY1N1
Ill llartla......,111. .. A. lalaa...._CAN171
Jla UUIUIII Ifs UUIMIII I ,ars..,.nma,-
SD-1
Tree Wells
BMP MAINTENANCE FACT SHEET
FOR
SITE DESIGN BMP SD-1 TREE WELLS
Tree wells as site design BMPs are trees planted in configurations that allow storm water runoff to be directed into
the soil immediately surrounding the tree. The tree may be contained within a planter box or structural cells. The
surrounding area will be graded to direct runoff to the tree well. There may be features such as tree grates,
suspended pavement design, or shallow surface depressions designed to allow runoff into the tree well. Typical
tree well components include:
• Trees of the appropriate species for site conditions and constraints
• Available growing space based on tree species, soil type, water availability, surrounding land uses, and
project goals
• Entrance/opening that allows storm water runoff to flow into the tree well (e.g., a curb opening, tree
grate, or surface depression)
• Optional suspended pavement design to provide structural support for adjacent pavement without
requiring compaction of underlying layers
• Optional root barrier devices as needed; a root barrier is a device installed in the ground, between a tree
and the sidewalk, intended to guide roots down and away from the sidewalk in order to prevent sidewalk
lifting from tree roots
• Optional tree grates; to be considered to maximize available space for pedestrian circulation and to
protect tree roots from compaction related to pedestrian circulation; tree grates are typically made up of
porous material that will allow the runoff to soak through
• Optional shallow surface depression for ponding of excess runoff
• Optional planter box drain
Normal Expected Maintenance
Tree health shall be maintained as part of normal landscape maintenance. Additionally, ensure that storm water
runoff can be conveyed into the tree well as designed. That is, the opening that allows storm water runoff to flow
into the tree well (e.g., a curb opening, tree grate, or surface depression) shall not be blocked, filled, re-graded, or
otherwise changed in a manner that prevents storm water from draining into the tree well. A summary table of
standard inspection and maintenance indicators is provided within this Fact Sheet.
Non-Standard Maintenance or BMP Failure
Tree wells are site design BMPs that normally do not require maintenance actions beyond routine landscape
maintenance. The normal expected maintenance described above ensures the BMP functionality. If changes have
been made to the tree well entrance / opening such that runoff is prevented from draining into the tree well (e.g.,
a curb inlet opening is blocked by debris or a grate is clogged causing runoff to flow around instead of into the tree
well, or a surface depression has been filled so runoff flows away from the tree well), the BMP is not performing as
intended to protect downstream waterways from pollution and/or erosion. Corrective maintenance will be
required to restore drainage into the tree well as designed.
Surface ponding of runoff directed into tree wells is expected to infiltrate/evapotranspirate within 24-96 hours
following a storm event. Surface ponding longer than approximately 24 hours following a storm event may be
detrimental to vegetation health, and surface ponding longer than approximately 96 hours following a storm event
poses a risk of vector (mosquito) breeding. Poor drainage can result from clogging or compaction of the soils
surrounding the tree. Loosen or replace the soils to restore drainage.
SD-1 Page 1 of 6
January 12, 2017
SD-1
Tree Wells
Other Special Considerations
Site design BMPs, such as tree wells, installed within a new development or redevelopment project are
components of an overall storm water management strategy for the project. The presence of site design BMPs
within a project is usually a factor in the determination of the amount of runoff to be managed with structural
BMPs (i.e., the amount of runoff expected to reach downstream retention or biofiltration basins that process
storm water runoff from the project as a whole). When site design BMPs are not maintained or are removed, this
can lead to clogging or failure of downstream structural BMPs due to greater delivery of runoff and pollutants than
intended for the structural BMP. Therefore, the [City Engineer] may require confirmation of maintenance of site
design BMPs as part of their structural BMP maintenance documentation requirements. Site design BMPs that
have been installed as part of the project should not be removed, nor should they be bypassed by re-routing roof
drains or re-grading surfaces within the project. If changes are necessary, consult the [City Engineer] to determine
requirements.
SD-1 Page 2 of 6
January 12, 2017
SD-1
Tree Wells
SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR SD-1 TREE WELLS
The property owner is responsible to ensure inspection, operation and maintenance of permanent BMPs on their property unless responsibility has been formally transferred to
an agency, community facilities district, homeowners association, property owners association, or other special district.
Maintenance frequencies listed in this table are average/typical frequencies. Actual maintenance needs are site-specific, and maintenance may be required more frequently.
Maintenance must be performed whenever needed, based on maintenance indicators presented in this table. The BMP owner is responsible for conducting regular inspections
to see when maintenance is needed based on the maintenance indicators. During the first year of operation of a structural BMP, inspection is recommended at least once prior
to August 31 and then monthly from September through May. Inspection during a storm event is also recommended. After the initial period of frequent inspections, the
minimum inspection and maintenance frequency can be determined based on the results of the first year inspections.
Threshold/Indicator Maintenance Action Typical Maintenance Frequency
Tree health Routine actions as necessary to maintain tree health. • Inspect monthly.
• Maintenance when needed.
Dead or diseased tree Remove dead or diseased tree. Replace per original
plans.
• Inspect monthly.
• Maintenance when needed.
Standing water in tree well for longer than 24 hours
following a storm event
Surface ponding longer than approximately 24 hours
following a storm event may be detrimental to tree
health
Loosen or replace soils surrounding the tree to restore
drainage.
• Inspect monthly and after every 0.5-inch or larger
storm event. If standing water is observed, increase
inspection frequency to after every 0.1-inch or larger
storm event.
• Maintenance when needed.
Presence of mosquitos/larvae
For images of egg rafts, larva, pupa, and adult
mosquitos, see
http://www.mosquito.org/biology
Disperse any standing water from the tree well to
nearby landscaping. Loosen or replace soils surrounding
the tree to restore drainage (and prevent standing
water).
• Inspect monthly and after every 0.5-inch or larger
storm event. If mosquitos are observed, increase
inspection frequency to after every 0.1-inch or larger
storm event.
• Maintenance when needed
Entrance / opening to the tree well is blocked such that
storm water will not drain into the tree well (e.g., a curb
inlet opening is blocked by debris or a grate is clogged
causing runoff to flow around instead of into the tree
well; or a surface depression is filled such that runoff
drains away from the tree well)
Make repairs as appropriate to restore drainage into the
tree well.
• Inspect monthly.
• Maintenance when needed.
SD-1 Page 3 of 6
January 12, 2017
SD-1
Tree Wells
References
American Mosquito Control Association.
http://www.mosquito.org/
County of San Diego. 2014. Low Impact Development Handbook.
http://www.sandiegocounty.gov/content/sdc/dpw/watersheds/susmp/lid.html
San Diego County Copermittees. 2016. Model BMP Design Manual, Appendix E, Fact Sheet SD-1.
http://www.projectcleanwater.org/index.php?option=com_content&view=article&id=250&Itemid=220
SD-1 Page 4 of 6
January 12, 2017
SD-1
Tree Wells
Date: Inspector: BMP ID No.:
Permit No.: APN(s):
Property / Development Name:
Responsible Party Name and Phone Number:
Property Address of BMP:
Responsible Party Address:
INSPECTION AND MAINTENANCE CHECKLIST FOR SD-1 TREE WELLS PAGE 1 of 2
Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted
Dead or diseased tree
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Remove dead or diseased tree
☐ Replace per original plans
☐ Other / Comments:
Standing water in tree well for longer than 24
hours following a storm event
Surface ponding longer than approximately 24
hours following a storm event may be
detrimental to tree health
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Loosen or replace soils surrounding the
tree to restore drainage
☐ Other / Comments:
SD-1 Page 5 of 6
January 12, 2017
I I
I
SD-1
Tree Wells
Date: Inspector: BMP ID No.:
Permit No.: APN(s):
INSPECTION AND MAINTENANCE CHECKLIST FOR SD-1 TREE WELLS PAGE 2 of 2
Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted
Presence of mosquitos/larvae
For images of egg rafts, larva, pupa, and adult
mosquitos, see
http://www.mosquito.org/biology
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Disperse any standing water from the tree
well to nearby landscaping
☐ Loosen or replace soils surrounding the
tree to restore drainage (and prevent
standing water)
☐ Other / Comments:
Entrance / opening to the tree well is blocked
such that storm water will not drain into the
tree well (e.g., a curb inlet opening is blocked by
debris or a grate is clogged causing runoff to
flow around instead of into the tree well; or a
surface depression is filled such that runoff
drains away from the tree well)
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Make repairs as appropriate to restore
drainage into the tree well
☐ Other / Comments:
SD-1 Page 6 of 6
January 12, 2017
ATTACHMENT 4
City standard Single Sheet BMP (SSBMP) Exhibit
[Use the City’s standard Single Sheet BMP Plan.]
1 1
---PN:
205-270-4 00
/
/
/
/
20
/
/,§1
/
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0
. '
SHIPPING
CONTAINER
GRAPHIC SCALE: 1" = 20'
20
6" PCC REINFORCED
CURB TYP PER GS
7" DEPRESSION
@CURB CUT PER
DETAILD-D
STREET FLOW
COMPACTED
SUBGRADE
SPLAS
PAD PER SDC GS
DSGS-5.06
ROOT BARRIER
PER SDRSD L-5
30 MIL PLASTIC
IMPERMEABLE LINER
6"SAND
FILTER LAYER
. ' I APN:
~i Ji \ 205-270-24-00 ' " V --:.,.,, ~-' • '
·-=----:=:s;~--v---,----.-I \
, APN.~, I
PLAN VIEW -SSBMP EXHIBIT
SCALE: 1" = 20' HORIZONTAL
40 60
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I
PARTY RESPONSIBLE FOR MAINTENANCE:
NAME: RINCON CAPITAL
ADDRESS: 5315AVENIDA ENCINAS, SUITE 200
CARLSBAD, CA 92008
PHONE NO: (BBB) 357-3553
CERTIFICATION:
PLAN PREPARED BY:
NAME: TYLER G LAWSON
COMPANY: PASCO, LARET, SUITER &
ASSOCIATES
ADDRES: 535 N. HWY 101, SUITE A
SOLANA BEACH, CA 92075
PHONE NO: (858) 259-8212
BMPNOTES:
SIGNATURE
1. THESE BMPS ARE MANDATORY TO BE INSTALLED PER THESE PLANS
2. NO CHANGES TO THE PROPOSED BMPS ON THIS SHEET WITHOUT PRIOR APPROVAL
FROM THE CITY ENGINEER
3. NO SUBSTITUTIONS TO THE MATERIAL OR TYPES OR PLANTING TYPES WITHOUT
PRIOR APPROVAL FROM THE CITY ENGINEER.
4. NO OCCUPANCY WILL BE GRANTED UNTIL THE CITY INSPECTION STAFF HAS
INSPECTED THIS PROJECT FOR APPROPRIATE BMP CONSTRUCTION AND
INSTALLATION.
5. REFER TO MAINTENANCE AGREEMENT DOCUMENT.
6. SEE PROJECT SWQMP FOR ADDITIONAL INFORMATION.
BMP CONSTRUCTION AND INSPECTION NOTES:
THE EOWWILL VERIFY THAT ALL PERMANENT BMPS -INCLUDING BMPS LOCATED WITHIN THE
BUILDING -ARE CONSTRUCTED AND OPERATING IN COMPLIANCE WITH THE APPLICABLE
REQUIREMENTS. PRIOR TO OCCUPANCY THE EOW MUST PROVIDE:
1. PHOTOGRAPHS OF THE INSTALLATION OF PERMANENT BMPS PRIOR TO
CONSTRUCTION, DURING CONSTRUCTION, AND AT FINAL INSTALLATION.
2. A WET STAMPED LETTER VERIFYING THAT PERMANENT BMPS ARE CONSTRUCTED
AND OPERATING PER THE REQUIREMENTS OF THE APPROVED PLANS.
3. PHOTOGRAPHS TO VERIFY THAT PERMANENT WATER QUALITY TREATMENT SIGNAGE
HAS BEEN INSTALLED.
PRIOR TO RELEASE OF SECURITIES, THE DEVELOPER IS RESPONSIBLE FOR ENSURING THE
PERMANENT BMPS HAVE NOT BEEN REMOVED OR MODIFIED BY THE NEW HOMEOWNER OR
HOA WITHOUT THE APPROVAL OF THE CITY ENGINEER.
"B/OFILTRA T/ON "ENGINEERED SOIL"
LAYER SHALL BE MINIMUM 18" DEEP
PER CITY OF CARLSBAD BMP MANUAL
APPENDIX F.3-BIORETENTION SOIL
MEDIA (BSM) SPECIFICATION
FG =87.5
1.0%-2.0%
82.75 BOTTOM OF BASIN
ELEVATION; PERMEABLE
GEOTEXTILE FABRIC TO
6" FREEBOARD
AND CONVEYANCE
ABOVE RISER
6"
6" PVC OUTLET PIPE FROM
PERMAVOJD MODULE SYSTEM
TO CONNECT TO OUTLET
12"PONDJNG
DEPTH
36" X 36" BROOKS
BOX;87.0 TG
BMP TABLE
><
><
BMP ID# BMP TYPE SYMBOL CASQA NO. QUANTITY
HYDROMODIFICATION & TREATMENT CONTROL
(i) '2' BIOFILTRATION ~~••:,1 -'-=.J BASIN t • • , TC-32
TREATMENT CONTROL
STREET
TREE WELL
SITE DESIGN
SUBSTAINABLE
LANDSCAPING
DIRECT RUNOFF
TO PERVIOUS AREAS
SOURCE CONTROL
BMP/WATER @-® QUALITY SIGN
FENCING PER
LANDSCAPE PLANS
87.5TOP
OF SLOPE
PROPOSED DEEPENED
EDGE AT ll'b\LKIM\Y; SEE
DETAJL SHEET 5
6"
18"
IXI SD-1 2 EA
11,825 SF.
e 12 EA
SD-13 24EA
6" FREEBOARD
AND CONVEYANCE
ABOVE RISER
18"PONDING
DEPTH
36" X 36" BROOKS
BOX;87.0TG
ORIFICE PLATE
PER DETAIL SHEET
5, DRJLLED TO
INSIDE OF BOX 18" ENGINEERED SOIL \I_
LAYER; "SEE NOTE BELOW \
PERMEABLE GEOTEXTILE FABRIC \·. LAYER (MIRAFI 1100N OR EQUAL)
BE1\IVEEN PEA GRAVEL LAYER
AND PERMAVOID SYSTEM <J::t..L.I LI _ _j..l-'--~-~;'-l/.
82.25 BOTTOM OF BASIN
ELEVATION; PERMEABLE
GEOTEXTILE FABRIC TO
6" PVC OUTLET PIPE FROM
PERMAVOID MODULE SYSTEM
TO CONNECT TO OUTLET
WRAP PERMAVOID SYSTEM STRUCTURE WI ORIFICE PLATE 8" PVC EMERGENCY
OVERFLOW OUTLET
DRAIN PIPE, 82.5 IE DUT 0.5" HMP-SIZED ---~
LOW-FLOW ORIFICE, DRILLED
INTO ORIFICE PLATE; 82.5 IE
DRAWING NO.
SD-A
SD-K
SD-B
SD-F
SHEET NO.(S)
DWG534-5A
SHEETS 4
DWG 534-5
SHEETS 3
DWG534-5A
SHEETS 4
DWG534-5A
SHEETS 4
DWG534-5A
SHEETS 4
INSPECTION
FREQUENCY
SEMI-ANNUALLY
SEMI-ANNUALLY
ANNUALLY
ANNUALLY
MAINTENANCE
FREQUENCY
ANNUALLY &
AS-NEEDED
SEMI-ANNUALLY
&AS-NEEDED
MONTHLY
AS-NEEDED
PLANT MIX PER
LANDSCAPE
ARCHITECT PLAN
FENCING PER ___J
LANDSCAPE PLANS ><
87.5TOP
87.03' OF SLOPE
100-YR WSEL PROPOSED DEEPENED
EDGE AT ll'b\LKIM\Y; SEE
DETAIL SHEET 5
3" LAYER OF 318" PEA
GRAVEL
><
IMPERMEABLE LINER
(MIRAFI 30-MIL140N
ORAPPROVED
EQUAL) ALONG
SIDES OF BMP ONLY
~ EXISTING GRADE
18" LAYER PERMAVOID SYSTEM (3
X PV150 MODULE VW 95% VOID
RATIO) OR APPROVED EQUAL
PERMEABLE GEOTEXTILE FABRIC
LAYER (MIRAFI 1100N OR EQUAL)
BETWEEN PEA GRAVEL LAYER
-1'-1.5' MAX ENGINEERED FILL MATERIAL AND PERMAVOID SYSTEM
BETWEEN BASIN BOTTOM AND NATIVE
MATERIAL SELECTIVELY GRADED PER
GEOTECH RECOMMENDATION TO PROVIDE
RELIABLE INFILTRATION PROPERTIES
PLANT MIX PER
LANDSCAPE
ARCHITECT PLAN
TYPICAL DETAIL-BMP-1 BIOFILTRATION BASIN WI PARTIAL RETENTION
NOTTO SCALE
FG=87.5
86.7'
100-YR WSEL 1.0%-2.0%
4.0' LIMITS OF STRUCTURAL SOIL 6"X 18"
DEEPENED EDGE
REINFORCED
WRAP PERMAVOID SYSTEM STRUCTURE WI ORIFICE PLATE
6" PVC EMERGENCY
OVERFLOW OUTLET
DRAJN PIPE; 83. 0 IE OUT
-1'-1.5' MAX ENGINEERED FILL MATERIAL 'BIOFILTRA TION "ENGINEERED SOIL•
3"MINMULCH
LAYER
"6"
UNCOMPACTEDSUBGRADE
PCC SJDEll'b\LK
PERGS-1.04B
COMPACTED
SUBGRADE
30 MIL PLASTIC
IMPERMEABLE LINER
48"DEEP
STRUCTURAL SOIL•
DEEP ROOT TREE
BUBBLER PER
SDRSD DWG 1-4
I 'MODIFIED FROM STANDARD I
ADJACENT LANDSCAPED \
PVIIKY ON ADAMS
STREET
COMPACTED
SUBGRADE
10.0' LIMITS OF STRUCTURAL SOIL
r ADJACENTLANDSCAPED
PWKYONADAMS f 4:t f 3"MULCH 4:1\ STREET
~I \ , ~~~Rl~~~~~~~r-;~~~---+ + +: + + • • • ' +++++:+++ •••••••••~••••••••••••••••••••••••!••••••••: ~•!•••••j j•••••••••••••••••••••••• ; ~ COMPACTED
~ r; • -SUBGRAOE
r--I-ROOT H I I-
.~,,, __ :-:-:-:-__ ' -BALL tJ / : = f".-_ ROOT BARRIER
I I PER SDRSD L-6
'1--ll,,!1 ,,~~~~ ~ ---'--'--" -, -I '--30 MIL PLASTIC
__ , ----j / __
1
i..,.._:: IMPERMEABLELINER ;= ----1 --I I --1 ts
ROOT BARRIER Ii,,-'-'-'-':-:-:-:-:·-'--'--''--' ~;-;-;-;' . ..2...'..c....' i'TTi7 f.<::'--'--' ~-;-;'_c_'--'--' -,.......__ 48" DEEP
PERSDRSDL-5 ,----,--11111 ' ..___ ,.._ ,--STRUCTURALSOIL"
-::;:,/ "f.2 ~:i;:~c;:;_;:;;;;r~:ij~:~:;f:llf ~ lE~E"
LAYER UNCOMPACTED SU;c.BG='-RAO=E'-------~ I 'MODIFIED FROM STANDARD I
0A"HMP-SIZED ----
LOW-Fl.OW ORIFICE, DRILLED
INTO ORIFICE PLATE; 83.0 IE
BETWEEN BASIN BOTTOM AND NATIVE LAYER SHALL BE MINIMUM 18" DEEP
MATERIAL SELECTIVELY GRADED PER PER CITY OF CARLSBAD BMP MANUAL
GEOTECH RECOMMENDATION TO PROVIDE APPENDIX F.3-BIORETENTION SOIL
RELIABLE INFILTRATION PROPERTIES MED I A ( B s M) s p E c IF I c A Tl o N
TYPICAL DETAIL-BMP-2 BIOFILTRATION BASIN
WI PARTIAL RETENTION
SCALE: NOT TO SCALE
PASCO LARET SUITER
& ASSOCIATES
San Diego I Solana Beach I Orange County
Phone 858.259.8212 I www.plsaengineering.com
"AS BUILT"
RCE __ _ EXP. ___ _ DATE
REVIEWED BY:
INSPECTOR DATE
I SHEET I CITY OF CARLSBAD I SHEETS I l---+----11-----------------+---+---l---t----1 ENGINEERING DEPARTMENT
1---t---+----------------t-----11----t----t------1
SINGLE SHEET BMP SITE PLAN
ADAMS STREET HOMES
GR 2021-0041 SINGLE SHEET BMP PLAN CDP 2021-0043
SECTION 8-8 -TREE WELL WIO GRATE (AT ADAMS STREET)
MODIFIED SOC GS DS GS-1.04a + GS-1.04b SECTION A-A -TREE WELL WIO GRATE (AT ADAMS ST) ~------
MODIFIED SOC GS DS GS-1.04a + GS-1.04b NOTE. TREE WELL DETAILS FOR ADAMS STREET
RJGHT-OF-ll'b\Y SHOWN HEREON FOR
REFERENCE ONLY; SEE PUBLIC IMPROVEMENT
PLAN DWG 534-5 FOR CONSTRUCTION.
APPROVED: JASON S. GELDERT
ENGINEERING MANAGER RCE 63912 EXPIRES 9 30 22 DAlE
NOTTO SCALE
SCALE: NOT TO SCALE DA 1E INITIAL
ENGIIEER OF WORK REVISION DESCRIPTION
DA1E INITIAL
Oll£R APPROVAL
J:'ACTIVE JOBSl.3339 3745 ADAMS STREETICIVIL IDRAWINGIGRADING PLANSl3339-CV-GRAD-02-BMP.dwg
DA 1E INITIAL DWN BY:
CHKD BY: __ _
CITY APPROVAL RVWD BY:
PRO.ECT NO.
MS 2020-0004
DRAWING NO.
534-5A
PLSA 3339-01