HomeMy WebLinkAboutMS 02-05; CARLSBAD OCEANVIEW ESTATES; PRIORITY DEVELOPMENT PROJECT (PDP) STORM WATER QUALITY MANAGEMENT PLAN (SWQMP) FOR CARLSBAD OCEAN ESTATES; 2021-08-10CITY OF CARLSBAD
PRIORITY DEVELOPMENT PROJECT (PDP)
STORM WATER QUALITY MANAGEMENT PLAN (SWQMP)
FOR
CARLSBAD OCEANVIEW ESTATES
NE Corner of Hoover Street & Adams Street,
Carlsbad, CA, 92008
MS 02-05
ENGINEER OF WORK:
JOHN S. RIVERA, C73878
PREPARED FOR:
HENRY OLIVIER & ILEANA VISCAL
P.O. Box 9493
San Bernardino, CA 92427
Ph: (909) 880-1146
Fax: (909) 880-1557
HOlivier@Geo-Cal.com
PREPARED BY:
FUSION ENGINEERING AND TECHNOLOGY
1810 GILLESPIE WAY, SUITE 207 EL CAJON, CA 92020
Phone: 858-736-2800
Email: Johnny@FusionEngTech.com
REVISION DATE: AUGUST 10TH, 2021
REPLACES ORIGINAL APPROVAL DATED MAY 23, 2018
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
o Attachment la: OMA Exhibit
o Attachment lb: Tabular Summary of DMAs and Design Capture Volume Calculations
o Attachment le: Harvest and Use Feasibility Screening (when applicable)
o Attachment ld: Categorization of Infiltration Feasibility Condition (when applicable)
o Attachment le: Pollutant Control BMP Design Worksheets/ Calculations
• Attachment 2: Backup for PDP Hydromodification Control Measures
o Attachment 2a: Hydromodification Management Exhibit
o Attachment 2b: Management of Critical Coarse Sediment Yield Areas
o Attachment 2c: Geomorphic Assessment of Receiving Channels
o 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: CARLSBAD OCEANVIEW ESTATES
Project ID: MS 02-05
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.
_____________________________________C73878 Exp. 6/30/2023
Engineer of Work's Signature, PE Number & Expiration Date
John S. Rivera________________________________________________________
Print Name
Fusion Engineering & Technology_________________________________________
Company
August 10th, 2021____________________________
Date
No 73878
Exp .• 6/30/23
PROJECT VICINITY MAP
ADAMS
---........
AGUA
HEDIONDIA
LAGOON
CITY OF CARLSBAD
VICINITY MAP
NOT TO
SCALE
City of
sbad
STORM WATER STANDARDS
QUESTIONNAIRE
Development Services
land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
E-34
[ 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 appiied to a proposed development or redevelopment project. Depending on the outcome, your project will either be subject to 'STANDARD PROJECT' .requirements or be subject to 'PRIORITY DEVELOPMENT PROJECT' (PDP) requirements.
Your responses to the questionnaire represent an initial assessment of the p.roposed 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: CARLSBAD OCEANVIEW ESTATES PROJECT ID: MS 02-05
ADDRESS: NE Corner of Hoover Street & Adams Street, City of Carlsbad, CA APN: 206-180-32
The project is (check one): IX! New Development 0 Redevelopment
The total proposed disturbed area is: 48,041 ft2( 1.103 _) acres
-
The total proposed newly created and/or replaced impervious area is: -19,865 ft2 ( 0.456 ) acres
If your project is covered by an approved SWQMP as part of a larger develqpment project, provide the project ID and the
SWQMP # of the larger development project:
Project ID MS 02-05 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.
E-34 Page 1 of 4 REV 03/19
I
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 □ IZI or structure that do not alter the size (See Section 1.3 of the BMP Design Manual for guidance)?
If you answered "yes" to the above question, provide justification below then go to Step 5, mark the third box stating "my
project is not a 'development project' and not subject to the requirements of the BMP manual" and complete applicant
information.
i
Justification/discussion: (e.g. the project includes only interior remodels within an existing building):
If vou answered "no" to the above question, the project is a 'development project', i:io to Step 2.
STEP2
,, 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 □ 00 b) Designed and constructed to be hydraulically disconnected from pav13d 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 afe designed and constructed in □ 00 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? □ 00
'i
If you answered "yes" to one or more of the above questions, provide discussion/justification below, then go to Step 5, mark
the second box stating "my project is EXEMPT from PDP a -• ll and complete app!icant information.
Discussion to justify exemption ( e.g. the project redeveloping existing road designed and constructed in accordance with
the USEPA Green Street guidance):
'
If vou answered "no" to the above questions, vour project is not exempt from PDP, Qo to Step 3.
E-34 Page 2 of 4 REV 03/19
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, indµstrial, residential, mixed-use,
and ublic develo ment ro ·ects on ublic or rivate 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
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 sq'Jare feet or more of impervious
surface collectively over the entire project site and supports a hillside development project? A hillside
develo ment ro·ect includes develo ment on an natural slo e that is twent -five ercent or reater.
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
trans ortation of automobiles, trucks, motorc cles, and other vehicles.
7. Is your project a new or redevelopment project that creates and/or rep!aces 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 ro·ect to the ESA i.e. not commin led with flows fi'om ad·acent lands.*
8. Is your project a new development or redevelopment project that creates i;lnd/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 Standaro! Industrial Classification (SICj
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 (R,GO)? This category inciudes
RGO's that meet the following criteria: (a) 5,000 square feet or mom w (b) a project Average Daily
Traffic ADT of 100 or more vehicles er da . '
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. !s your project located within 200 feet of the Pacific Ocean and (1) create;s 2,500 square feet or more of
YES NO
[X] □
□
□ [X]
□ [X)
□ [X]
□ 00
□ 00
□
□ 00
IX! n
impervious surface or (2) increases impervious surface on the properly by more than 10%? (CMC D 00
21.203.040
If you answered "yes" to one or more of the above questions, your project is a PDP. If your project is a redevelopment
project, go to step 4. If your project is a new project, go to step 5, check the first box stating "My project is a PDP ... " and complete applicant information. •
; I If you answered "no" to all of the above questions, your project is a 'STAr•H)ARD PROJECT.' Go to step 5, check the second box statin "M ro·ect is a 'STANDARD PROJECT' .. ," and com lete'a licant information.
E-34 Page 3 of 4 REV 03/19
.. STEP4 1
TO BE COMPLETED FOR REDEVELOPMENT PROJECTS THAT ARE PR.IORITY DEVELOPMENT PROJECTS (PDP)
. ,· ONLY
Complete the questions below regarding your redevelopment project (MS4;P19rmit Provision E.3.b.(2)):
YES NO
Does the redevelopment project result in the creation or replacement of impprvious surface in an amount
of less than 50% of the surface area of the previously existing developnYlent? Complete the percent
impervious calculation below:
Existing impervious area (A) = sq. ft. i □ □
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 tp the creation or replacement of impervious
surface and not the entire development. Go to step 5, check the first bo>; ~tating "My project is a PDP ... " and complete
applicant information. !
if you answered "no," the structurai BMP's required for PDP apply to the entire development. Go to step 5, check the
check the first box statinQ "My project is a PDP ... " and complete applicant information.
STEPS
CHECK THE APPROPRIATE BOX AND COMPLETE APPLICANTINFORMATION
IXl My project is a PDP and must comply with PDP stormwater requirements of the BMP Manual. I understand I must
prepare a Storm Water Quality Management Plan (SWQMP) for submittal at time of application.
0 My project is a 'STANDARD PROJECT' OR EXEMPT from PDP and mqst only comply with 'STANDARD PROJECT'
stormwater requirements of the BMP Manual. As part of these requirements, I will submit a "Standard Project
Requirement Checklist Form E-36" and incorporate low impact development strategies throughout my project.
Note: For projects that are close to meeting the PDP threshold, staff may require detailed impervious area calculations
and exhibits to verify if 'STANDARD PROJECT' stormwater requirements apply.
D My Project is NOT a 'development project' and is not subject to the req4irements of the BMP Manual.
Applicant Information and Signature Box
i
Applicant Name: HENRY OLIVIER Applicant Title: OWNER _,,,,.., ..
Applicant Signature: (~~~/ &~"d,:1~ i Date: AugJst 10th, 2021
i
• Environmentally Sensitive Areas include but are not limited to all Clean Water Act Section 303(d) irnpaired water bodies; areas designated as Areas of Special
Siologica! Significar:co by the: State \"Jater Rescu1ces Cont;-o! Board (VVater Quality Control Plan for the San Diego Basin (1994) and amendments); water bodies
designated vvith the RARE beneficial use by the State VVatei Resources Control Bodid (VVatei Uuality Control Plan for the San Diego Basin (1994) and
amendments); areas designated as preser.Jes or their equivaient under the Multi Species Conservation Program vvithin the Cities and County of San Diego; Habitat
Management Plan; and any other equivalent environmentally sensitive areas which have been identified by the City.
This Box for City Use Onlv
r '· YES NO
City Concurrence: □ □
'
~y:
bate:
Project ID:
E-34 Page4of4 REV 03/19
SITE INFORMATION CHECKLIST
Project Summary Information
Project Name Carlsbad Oceanview Estates
Project ID MS 02-05
Project Address NE Corner of Hoover Street & Adams Street, Carlsbad,
CA, 92008
Assessor's Parcel Number(s) (APN(s))206-180-32
Project Watershed (Hydrologic Unit)Carlsbad 904
Parcel Area
__1.103__ Acres (48,041 Square Feet)
Existing Impervious Area
(subset of Parcel Area)__0.000__ Acres (0 Square Feet)
Area to be disturbed by the project
(Project Area)__1.103 _Acres (48,041 Square Feet)
Project Proposed Impervious Area
(subset of Project Area)__0.456__ Acres (19,865 Square Feet)
Project Proposed Pervious Area
(subset of Project Area)__0.647__ Acres (28,177 Square Feet)
Note: Proposed Impervious Area + Proposed Pervious Area = Area to be Disturbed by the Project.
This may be less than the Parcel Area.
The above numbers represent the onsite areas within the project lots, i.e. DMA’s 1, 2 & 3.
Additional project areas include the following;
·DMA 4 (DMA’s; 4.1, 4.2 & 4.3):
o Lot driveways within public ROW
o 250 s.f. each (750 s.f. total) new concrete driveway.
o Considered DeMinimis and not included within onsite lot biofiltration basin sizing.
·DMA 5:
o Widening of Adams Street on the opposite side of the project.
o 1,558 s.f. total new a.c. pavement
o Green Street design elements implemented including impervious dispersion to pervious surface
at edge of pavement, per Public Improvement Plan Dwg. No. 438-2.
Description of Existing Site Condition and Drainage Patterns
Current Status of the Site (select all that apply):
o Existing development
o Previously graded but not built out
o Agricultural or other non-impervious use
þ Vacant, undeveloped/natural
Description / Additional Information:
Existing Land Cover Includes (select all that apply):
þ Vegetative Cover
o Non-Vegetated Pervious Areas
o Impervious Areas
Description / Additional Information:
Underlying Soil belongs to Hydrologic Soil Group (select all that apply):
o NRCS Type A
þ NRCS Type B
o NRCS Type C
o NRCS Type D
Approximate Depth to Groundwater (GW):
o GW Depth < 5 feet
o 5 feet < GW Depth < 10 feet
o 10 feet < GW Depth < 20 feet
þ GW Depth > 20 feet
Existing Natural Hydrologic Features (select all that apply):
o Watercourses
o Seeps
o Springs
o Wetlands
þ 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]:
The existing site is comprised of vacant raw land with native and non-native vegetation cover. Runoff
from the approximately 1.10 acre site sheet flows to adjacent Adams Street and Hoover Avenue, and is
conveyed to existing catch basin at SE corner of Adams Street and Hoover Avenue.
Description of Proposed Site Development and Drainage Patterns
Project Description / Proposed Land Use and/or Activities:
The current project proposes pad and slope grading. Ultimately, Development of 3 Residential buildings
with associated hardscape and landscape improvements will be provided. However, the current phase
will only include the rough grading design without ultimate impervious areas.
List/describe proposed impervious features of the project (e.g., buildings, roadways, parking lots,
courtyards, athletic courts, other impervious features):
Minor street widening, driveway approach, curb and gutter as proposed impervious features per DWG
438-2. To contemplate the subsequent impervious area for the future development, the proposed
project DCV applies an assumed building and hardscape footprint.
List/describe proposed pervious features of the project (e.g., landscape areas):
The current project will have slopes and pads and apply Erosion Control Construction BMP’s. The future
project will apply formal landscape and irrigation for permanent stabilization of pervious surfaces.
Does the project include grading and changes to site topography?
þYes
No
Description / Additional Information:
The project proposes pad and slope grading to accommodate future construction of 3 residential
buildings and associated hardscape and landscape improvements.
Does the project include changes to site drainage (e.g., installation of new storm water conveyance
systems)?
þYes
No
Description / Additional Information:
The current project proposes ditches and swales within each lot to direct drainage to the respective
temporary sediment basins, which then discharge (from the basin via overflow structure) to Adams
Street and Hoover Avenue via Curb Outlet structures per the Public Improvement Plans. Ultimately, to
address pollutant control of the future building and associated hardscape improvements, the sediment
basins will be retrofitted to become Bioretention Basins per future Precise Grading Plans.
Identify whether any of the following features, activities, and/or pollutant source areas will be present
(select all that apply):
þ On-site storm drain inlets
o Interior floor drains and elevator shaft sump pumps
o Interior parking garages
o Need for future indoor & structural pest control
o Landscape/Outdoor Pesticide Use
o Pools, spas, ponds, decorative fountains, and other water features
o Food service
o Refuse areas
o Industrial processes
o Outdoor storage of equipment or materials
o Vehicle and Equipment Cleaning
o Vehicle/Equipment Repair and Maintenance
o Fuel Dispensing Areas
o Loading Docks
o Fire Sprinkler Test Water
o Miscellaneous Drain or Wash Water
o 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):
All proposed runoff volume will be detained into the proposed bioretention systems and emergency
overflow into Hoover and Adam Street through an existing 12” drainage pipe crossing adjacent
residential property. An existing 6 feet wide storm drain easement for the drainage pipe was shown on
City drawing No. R-332.
List any 303(d) impaired water bodies within the path of storm water from the project site to the Pacific
Ocean (or bay, lagoon, lake or reservoir, as applicable), identify the pollutant(s)/stressor(s) causing
impairment, and identify any TMDLs for the impaired water bodies:
303(d) Impaired Water Body Pollutant(s)/Stressor(s)TMDLs
Agua Hedionda (Creek/ Lagoon) Enterococcus, Coliform,
Manganese, Phosphorus,
Nitrogen, Selenium, Diazinon &
Toxicity
N/A
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 X
Organic Compounds X
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)?
o Yes, hydromodification management flow control structural BMPs required.
þ 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.
o 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.
o 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?
o Yes
þ 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?
o 6.2.1 Verification of Geomorphic Landscape Units (GLUs) Onsite
o 6.2.2 Downstream Systems Sensitivity to Coarse Sediment
o 6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite
o 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?
o No critical coarse sediment yield areas to be protected based on verification of GLUs onsite
o Critical coarse sediment yield areas exist but additional analysis has determined that protection is not
required. Documentation attached in Attachment 8 of the SWQMP.
o Critical coarse sediment yield areas exist and require protection. The project will implement
management measures described in Sections 6.2.4 and 6.2.5 as applicable, and the areas are
identified on the SWQMP Exhibit.
Discussion / Additional Information:
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.
N/A
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.
N/A (Refer to Attached CCSYA MAP)
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.
CARLSBADCARLSBAD
ENCINITASENCINITAS
ESCONDIDOESCONDIDO
OCEANSIDEOCEANSIDE
POWAYPOWAY
S.D.S.D.COUNTYCOUNTY
S.D.S.D.COUNTYCOUNTY
S.D.S.D.COUNTYCOUNTY
SANSANDIEGODIEGO
SANSANMARCOSMARCOS
VISTAVISTA
WINDMILLLAKE GUAJOMELAKE
HUBBERTLAKE TURNERLAKE
LAKEWOHLFORDCALAVERASLAKEBUENAVISTALAGOONDIXONRESERVOIRSQUIRESDAMAQUAHEDIONDALAGOON
BATIQUITOSLAGOON
SANDIEGUITORESERVOIR RESERVOIR
LAKEPOWAY
SAN DIEGUITOLAGOON
LAKERAMONA
LAKEHODGES S a nDie
g
u
ito
Rive r
San M a r c os C r ee k
S
a
n
Marcos C reek
E scondi
d o Creek
Rattles n a k e Creek
B u e na V i s t a Cree k
Sa n Luis ReyRiver
Lu sardi Cree k
E
n
c
i
n
it
a
sCr e ek
S a n t a Y s a b el C reek
S a n ta Margarita
R
iver
A g u a Hedionda Creek
S a n L u i s Re yRiver
Potential Critical Coarse Sediment Yield Areas
Exhibit Date: Sept. 8, 2014Carlsbad Watershed - HU 904.00, 211 mi2
Aerial Imagery Source: DigitalGlobe, 06/2012
0 50 100 15025Miles
Legend
Watershed Boundaries
Municipal Boundaries
Rivers & Streams
Regional WMAA Streams
Potential Critical Coarse Sediment Yield Areas
NORTH
I
Geosyntec C> RICK
consultants ENGINEERI NG C OMPANY
DGot~ll-ltf .. w-
v.iii;~laf -'I-•
' "
Salt
Cil
j
a
C cityof
Carlsbad
STANDARD PROJECT
REQUIREMENT
CHECKLIST
E-36
Project Information
Project Name: Carlsbad Oceanview Estates
Project ID: MS 02-05
DWG No. or Building Permit No.: 438-2A
Source Control BMPs
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible. See
Chapter 4 and Appendix E.1 of the BMP Design Manual (Volume 5 of City Engineering Standards) for information to
implement source control BMPs shown in this checklist.
Answer each category below pursuant to the following.
• "Yes" means the project will implement the source control BMP as described in Chapter 4 and/or Appendix E.1 of the
Model BMP Design Manual. Discussion/justification is not required.
• "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion/justification must be
provided. Please add attachments if more space is needed.
• "N/A" means the BMP is not applicable at the project site because the project does not include the feature that is
addressed by the BMP (e.g., the project has no outdoor materials storage areas). Discussion/justification may be
provided.
Source Control Requirement Applied?
SC-1 Prevention of Illicit Discharges into the MS4 ~Yes □ No □ N/A
Discussion/justification if SC-1 not implemented:
SC-2 Storm Drain Stenciling or Signage ~ Yes □ No □ N/A
Discussion/justification if SC-2 not implemented:
SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind □ Yes □ No ~ N/A Dispersal
Discussion/justification if SC-3 not implemented:
There are no outdoor material storage areas proposed.
E-36 Page 1 of 4 Revised 09/16
E-36 Page 2 of 4 Revised 09/16
Source Control Requirement (continued) Applied?
SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and
Wind Dispersal Yes No N/A
Discussion/justification if SC-4 not implemented:
SC-5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal Yes No N/A
Discussion/justification if SC-5 not implemented:
SC-6 Additional BMPs based on Potential Sources of Runoff Pollutants must answer for each source listed below and
identify additional BMPs. (See Table in Appendix E.1 of BMP Manual for guidance).
On-site storm drain inlets Yes No N/A
Interior floor drains and elevator shaft sump pumps Yes No N/A
Interior parking garages Yes No N/A
Need for future indoor & structural pest control Yes No N/A
Landscape/Outdoor Pesticide Use Yes No N/A
Pools, spas, ponds, decorative fountains, and other water features Yes No N/A
Food service Yes No N/A
Refuse areas Yes No N/A
Industrial processes Yes No N/A
Outdoor storage of equipment or materials Yes No N/A
Vehicle and Equipment Cleaning Yes No N/A
Vehicle/Equipment Repair and Maintenance Yes No N/A
Fuel Dispensing Areas Yes No N/A
Loading Docks Yes No N/A
Fire Sprinkler Test Water Yes No N/A
Miscellaneous Drain or Wash Water Yes No N/A
Plazas, sidewalks, and parking lots Yes No N/A
For “Yes” answers, identify the additional BMP per Appendix E.1. Provide justification for “No” answers.
There are no material storage areas proposed.
Single family residence trash cans are self enclosed to prevent contact with rain or wind.
1. Onsite storm drain inlets have been designed per each lots and it was connected into proposed
BMP; all inlets will be signed "No dumpling! Flow to Bay";
BMP belongs to retention - infiltration INF-2 Bioretention per Appendix E.1
2. Drought tolerant plants used, pest resistant plants / hydroseed used.
□ Iii □
Iii □ □
Iii Iii □ □
□ □ □ Iii
□ □ □ Iii
□ □ □ Iii
Iii Iii □ □
□ □ □ Iii
□ □ □ Iii
□ □ □ Iii
□ □ □ Iii
□ □ □ Iii
□ □ □ Iii
□ □ □ Iii
□ □ □ Iii
□ □ □ Iii
□ □ □ Iii
□ □ □ Iii
□ □ □ Iii
Site Design BMPs
All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible. See
Chapter 4 and Appendix E.2 thru E.6 of the BMP Design Manual (Volume 5 of City Engineering Standards) for information
to implement site design BMPs shown in this checklist.
Answer each category below pursuant to the following.
• "Yes" means the project will implement the site design BMPs as described in Chapter 4 and/or Appendix E.2 thru E.6 of
the Model BMP Design Manual. Discussion/ justification is not required.
• "No" means the BMPs is applicable to the project but it is not feasible to implement. Discussion/justification must be
provided. Please add attachments if more space is needed.
• "N/A" means the BMPs is not applicable at the project site because the project does not include the feature that is
addressed by the BMPs (e.g., the project site has no existing natural areas to conserve). Discussion/justification may be
provided.
Site Design Requirement I Applied?
SD-1 Maintain Natural Drainage Pathways and Hydrologic Features I ~Yes I □ No I □ N/A
Discussion/justification if SD-1 not implemented:
SD-2 Conserve Natural Areas, Soils, and Vegetation I ~ Yes I □ No I □ N/A
Discussion/justification if SD-2 not implemented:
SD-3 Minimize Impervious Area I ~ Yes I □ No I □ N/A
Discussion/justification if SD-3 not implemented:
SD-4 Minimize Soil Compaction I ~ Yes I □ No I □ N/A
Discussion/justification if SD-4 not implemented:
SD-5 Impervious Area Dispersion I ~ Yes I □ No I □ N/A
Discussion/justification if SD-5 not implemented:
E-36 Page 3 of 4 Revised 09/16
Site Design Requirement (continued) I Applied?
SD-6 Runoff Collection I iii Yes I □ No I □ N/A
Discussion/justification if SD-6 not implemented:
SD-7 Landscaping with Native or Drought Tolerant Species I Iii Yes I □ No I □ N/A
Discussion/justification if SD-7 not implemented:
SD-8 Harvesting and Using Precipitation I □ Yes I Iii No I □ N/A
Discussion/justification if SD-8 not implemented:
Infeasible per worksheet 1-7.
E-36 Page 4 of 4 Revised 09/16
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.
Estimated total DCV after adjust runoff factor to account for site design BMPs:
DMA 1: 427 c.f.
DMA 2: 419 c.f.
DMA 3: 357 c.f.
Harvest and use are considered infeasible.
Required demand for harvest and use / DCV: 25%
Estimated demand for harvest and use/estimated total DCV: 20%
Partial infiltration on site: Feasible, partial infiltration BMP’s details see Attachment 1e – Pollutant
control BMP Design Worksheet.
Note: Partial Retention by Biofiltration Basins are sized based on assumed future impervious area once
each lot is developed with residential buildings and associated hardscape improvements. The future
Partial Retention by Biofiltration Basins shall be installed after future precise grading plans are approved
for the development of single-family homes. Sedimentation basins shall be installed per approved rough
grading plans until such time.
Structural BMP Summary Information
[Copy this page as needed to provide information for each individual proposed structural BMP]
Structural BMP ID No. PR-1-1
DWG ___TBD____ Sheet No. __TBD______
Type of structural BMP:
o Retention by harvest and use (HU-1)
o Retention by infiltration basin (INF-1)
o Retention by bioretention (INF-2)
o Retention by permeable pavement (INF-3)
x Partial retention by biofiltration with partial retention (PR-1)
o Biofiltration (BF-1)
o Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or
biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration
BMP it serves in discussion section below)
o Detention pond or vault for hydromodification management
o Other (describe in discussion section below)
Purpose:
þ Pollutant control only
o Hydromodification control only
o Combined pollutant control and hydromodification control
o Pre-treatment/forebay for another structural BMP
o Other (describe in discussion section below)
Discussion (as needed):
BMP PR-1-1 is a Partial Retention by Biofiltration with Partial Retention Basin with bottom area of 261 s.f..
See attached DMA site map for details.
Structural BMP Summary Information
[Copy this page as needed to provide information for each individual proposed structural BMP]
Structural BMP ID No. INF-2-2
DWG ___TBD____ Sheet No. __TBD______
Type of structural BMP:
o Retention by harvest and use (HU-1)
o Retention by infiltration basin (INF-1)
o Retention by bioretention (INF-2)
o Retention by permeable pavement (INF-3)
x Partial retention by biofiltration with partial retention (PR-1)
o Biofiltration (BF-1)
o Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or
biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration
BMP it serves in discussion section below)
o Detention pond or vault for hydromodification management
o Other (describe in discussion section below)
Purpose:
þ Pollutant control only
o Hydromodification control only
o Combined pollutant control and hydromodification control
o Pre-treatment/forebay for another structural BMP
o Other (describe in discussion section below)
Discussion (as needed):
BMP PR-1-1 is a Partial Retention by Biofiltration with Partial Retention Basin with bottom area of 256 s.f..
See attached DMA site map for details.
Structural BMP Summary Information
[Copy this page as needed to provide information for each individual proposed structural BMP]
Structural BMP ID No. INF-2-3
DWG ___TBD____ Sheet No. __TBD______
Type of structural BMP:
o Retention by harvest and use (HU-1)
o Retention by infiltration basin (INF-1)
o Retention by bioretention (INF-2)
o Retention by permeable pavement (INF-3)
x Partial retention by biofiltration with partial retention (PR-1)
o Biofiltration (BF-1)
o Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or
biofiltration BMP (provide BMP type/description and indicate which onsite retention or biofiltration
BMP it serves in discussion section below)
o Detention pond or vault for hydromodification management
o Other (describe in discussion section below)
Purpose:
þ Pollutant control only
o Hydromodification control only
o Combined pollutant control and hydromodification control
o Pre-treatment/forebay for another structural BMP
o Other (describe in discussion section below)
Discussion (as needed):
BMP PR-1-1 is a Partial Retention by Biofiltration with Partial Retention Basin with bottom area of 218 s.f..
See attached DMA site map for details.
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 Contents Checklist
Sequence
Attachment 1 a OMA Exhibit (Required) ~ Included
See OMA Exhibit Checklist on the back
of this Attachment cover sheet.
(24"x36" Exhibit typically required)
Attachment 1 b Tabular Summary of DMAs Showing ~ Included on OMA Exhibit in
OMA ID matching OMA Exhibit, OMA Attachment 1a
Area, and OMA Type (Required)* □ Included as Attachment 1 b,
*Provide table in this Attachment OR on
OMA Exhibit in Attachment 1 a
separate from OMA Exhibit
Attachment 1c Form 1-7, Harvest and Use Feasibility ~ Included
Attachment 1 d
Screening Checklist (Required unless □ Not included because the entire
the entire project will use infiltration project will use infiltration BMPs
BMPs)
Refer to Appendix B.3-1 of the BMP
Design Manual to complete Form 1-7.
Form 1-8, Categorization of Infiltration
Feasibility Condition (Required unless
the project will use harvest and use
BMPs)
Refer to Appendices C and D of the
BMP Design Manual to complete
Form 1-8.
~ Included
□ Not included because the entire
project will use harvest and use
BMPs
Attachment 1 e Pollutant Control BMP Design ~ Included
Worksheets / Calculations (Required)
Refer to Appendices B and E of the
BMP Design Manual for structural
pollutant control BMP design
guidelines
ATTACHMENT 1a
OMA EXHIBIT
DMA 1
H
O
O
V
E
R D
RIV
E
A D A M S S T R E E T
P RIV A T E D RIV E W A Y
DMA 2
DMA 3
DMA 4.1
DMA 4.2
DMA 4.3
DMA 5
PR-1-1
PR-1-2
PR-1-3
PARCEL 1
PARCEL 2
PARCEL 3
***
SOURCE CONTROL BMPS SEE FORM E-36 IN
SWQMP
• PREVENTION OF ILLICIT DISCHARGE TO THE
MS4
·PROTECT TRASH STORAGE AREAS FROM
RAINFALL, RUN-ON, RUNOFF, AND WIND
DISPERSAL
·NEED FOR INDOOR PEST CONTROL
·LANDSCAPE/OUTDOOR PESTICIDE USE
·SWEEP SIDEWALKS REGULARLY
SITE DESIGN BMPS SEE FORM E-36 IN SWQMP
·MAINTAIN NATURAL DRAINAGE PATHWAYS
AND HYDROLOGIC FEATURES
·MINIMIZE IMPERVIOUS AREA
·MINIMIZE SOIL COMPACTION
·IMPERVIOUS AREA DISPERSION
·RUNOFF COLLECTION
• LANDSCAPING WITH NATIVE OR DROUGHT
TOLERANT PLANTS
NOTES
·GROUNDWATER DEPTH > 20 FEET
·NO CCSYAS PRESENT ONSITE OR DRAINING
THROUGH THE PROJECT BOUNDARY PER
WMAA MAP
PROPERTY LINE
DMA BOUNDARY
SUBAREA ACREAGE
DMA ICON
HYDROLOGIC SOIL TYPE
POINT OF COMPLIANCE
DMA 1 - SEE TABLE
DMA 2 - SEE TABLE
DMA 3 - SEE TABLE
DMA 4 - SEE TABLE
DMA 5 - SEE TABLE
DMA 1
BMP TYPEBMP ID #SYMBOL CASQA NO.DRAWING NO.SHEET NO.(S)MAINTENANCEFREQUENCY
BMP TABLE
INSPECTION FREQUENCYQUANTITY
TREATMENT CONTROL
PR-1-1 PARTIAL RETENTION SEMI-ANNUALLY438-2A 3
**
ANNUALLYBY BIOFILTRATION
PR-1-2
PR-1-3 *
FUTURE PGP
438-2AFUTURE PGP
438-2AFUTURE PGP
1 EA.261 S.F.
1 EA.256 S.F.
1 EA.218 S.F.
SEMI-ANNUALLY3 ANNUALLY
SEMI-ANNUALLY3 ANNUALLY
PER REQUEST OF CITY OF CARLSBAD TEMP SEDIMENT BASINS WILL BE PROVIDED WITHIN THE FOOTPRINT OF THE ASSUMED FUTURE
PARTIAL RETENTION BY BIOFILTRATION WITH PARTIAL RETENTION BASIN.
THE TEMP SEDIMENT BASIN WILL BE PROVIDED IN ADDITION TO THE STANDARD EROSION CONTROL CONSTRUCTION BMP'S PROVIDED
FOR TYPICAL SINGLE FAMILY GRADED PADS.
FUTURE PARTIAL RETENTION BY BIOFILTRATION WITH PARTIAL RETENTION BASINS TO BE CONSTRUCTED WITH DEVELOPMENT OF
LOTS.
**TC-32 / FT-4
TC-32 / FT-4
TC-32 / FT-4
PARTIAL RETENTIONBY BIOFILTRATION
PARTIAL RETENTIONBY BIOFILTRATION
/
/ /
/ 1
/ I
/
/
0.006 ACRE
' ~
""' \ '
I ;
I
""'
/
y
/ I
C
/ I
f I ,,
/ I
/1 (
, 1
I
/
/
I
I
\
\
' / V
a a
.t a
,..------y
L, .... ~~ a
',""'---.;;;~ -'---.... --,,-...... ---c:=--. ......_ ...... --CJO<...r--:::.-
,,..----es~~~'Jtf~~-~ff"-~CJ:::,:<?~--. -9 c:i ----
C'~"""-\C""-2 2:1
----{ I
I I
l
\
-----,
,, ,, ,, ,..o--F ···-···-,/
.-::;;o.--c;::-:..:::,,···-.... / .... -, ·•, / " ' / ·•,
'•
\
\
r \ 1 I
( : i I
' ' \
l
I
I
I 0.369 ACRES I I
\
~ F \ '--::_::_::_+
c"<,
'ASSUMED
FUTURE
IMPERVIOUS
AREA
......._ -----<>--.
""' '
""' '
\
F
~
~ \
' ' ', ---
C
-----o-----~-
I
I
I
i
I
URB oun.a
i
\
\ ----
I
i
I
/B\ ( ) \ / \ _ _/
•SEE TABLE AT
RIGHT FOR
ASSUMED FUTURE
IMPERVIOUS AREAS
,1i-----------
! ~'jj
I j I 0.355 ACRES I I , ,' i
----
---
"
--,
I
I
I
I
I
I
\
\
\
I to I'=='"-'-~
CURB 0/JTl.IT
I -
I
I 0.006 ACRES
-
----------,
\
-··--
\
\
\
\
----........ __ -, .........
-----
I 0.378 ACRES I
'ASSUMED
FUTURE
IMPERVIOUS
AREA
----
.... '• ' '
0.006 ACRES
11
q
PROPERTY
BOUNDARY
'l-
J---
0 A 0.036 ACRESL-----------
u
LEGEND
--------
20 0 2_0 _____ 40 60
SCALE 1"= 20'
OMA 1-PR
Runoff Summation
OMA Description OMA Type Factor % Imper Area (ac.) Area (s.f.) Runoff Factor
x Area {ac.)
moretention Basin Engineered Pervious Surface 0.10 0% 0.006 261 0.0006
Natural Slooe Natural Tvne 'B' Soil 0.14 0% 0.065 2825 0.0091
Landscape Slope / Pad Semi-Pervious Surface 0.30 0% 0.131 5692 0.0392
Roof/Hardscape/Driveway Impervious Surface 0.90 100% 0.168 7305 0.1509
Total Total Arota1= 0.369 16083 0.1998
Total Total Ached,= 0.369 Rfeompo,lte-DMA= 0 .54
OMA 2-PR
Runoff Summation
DMA Description DMA Type Factor % Imper Arec1 (nc.) Area (s.f.) Runoff Factor
x Area (ac.)
Bioretention Basin Engineered Pervious Surface 0.10 0% 0.006 256 0.0006
Natural Slope Natural T~·pe 'B' Soil 0.14 0% 0.059 2552 0.0082
Landscape Slope/ Pad Semi-Pervious Surface 0.30 0% 0.126 5499 0.0379
Roof/Hardscape/Driveway Impervious Surface 0.90 100% 0.165 7170 0.1481
Total Total Arota1= 0.355 15477 0.1948
Total Total Ac~cd= 0.355 Rfcompo•itc-DMA= 0.55
OMA 3-PR
Runoff Summation
OMA Description OMA Type % Imper Area (ac.) Area (s.f.) Runoff Factor Factor x Area {ac.)
Bioretention Basin Engineered Pervious Surface 0.10 0% 0.005 218 0.0005
Natural Slope Natural Type 'B' Soil 0.14 0% 0.122 5302 0.0170
Landscape Slope/ Pad Semi-Pervious Surface 0.30 0% 0.128 5572 0.0384
Roof/Hardscape/Driveway Impervious Surface 0.90 100% 0.124 5390 0.1114
Total Total A101a1= 0.378 0.378 0.1673
Total Total ~.l1na= 0.378 Rf Composit~-DMA = 0.44
DMA 4-PR (DeMinimis, 250 s.f. per Lot Driveway Entrance)
Runoff Summation
DMA Description OMA Type % Imper Area (ac.) Area (s.f.) Runoff Factor Factor xArea (ac.)
Driveway (ROW) Impervious Surfc1ce 0.90 100% 0.017 750 0.0155
Total Total Arotal= 0.017 750 0.0155
Total Total Ach~d= 0.017 Rfeomposilo-OMA= 0.90
DMA 5-PR (Adams Street Widening Opposite Side of Project)
Runoff Summation
OMA Description DMA Type % Imper Area (ac.) Area {s.f.) Runoff Factor Factor x Area {ac.)
Pavement (Adams Street) Impervious Surface 0.90 100% 0.036 1558 0.0322
Total Total A1ota1= 0.036 1558 0.0322
Total Total Ached= 0.036 Rfeomposit~-DMA= 0.90
Note: Roof/Hardscape/Driveway in table are projected impervious area for Planning purposes. Actual areas may vary and require
adjustment to bioretention basin sizes during building permit phase.
Note: DMAS implements Greet Street design elements including impervious dispersion to pervious surface at edge of pavement.
PREPARED BY=
Fusion Eng Tech
1810 Gillespie Way, Suite 207
El Cajon, CA 92020
(619) 736-2800
I xx.xx ACRES I
DEVELOPED CONDITION
DRAINAGE MANAGEMENT AREA MAP
CARLSBAD OCEANVIEW
ESTATES
CITY OF CARLSBAD, CALIFORNIA
MAP
1
OF
2
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------R:\0109-0001 Corlsbod Ocecnview Estotes -Olivier, Henry\ Hy d \SW QM P \CAD\ 0109-0001 $SWQMP _DMA.dwg□Jun-24-2021 :15: 18
g
0
I fl
0
"" ci
3'
ATTACHMENT 1 b
TABULAR SUMMARY OF OMA
DMA Description DMA Type Runoff
Factor % Imper Area (ac.)Area (s.f.)
Summation
Runoff Factor
x Area (ac.)
Bioretention Basin Engineered Pervious Surface 0.10 0%0.006 261 0.0006
Natural Slope Natural Type 'B' Soil 0.14 0%0.065 2825 0.0091
Landscape Slope / Pad Semi-Pervious Surface 0.30 0%0.131 5692 0.0392
Roof/Hardscape/Driveway Impervious Surface 0.90 100%0.168 7305 0.1509
Total Total ATotal=0.369 16083 0.1998
Total Total ACheck=0.369 RFComposite-DMA=0.54
DMA Description DMA Type Runoff
Factor % Imper Area (ac.)Area (s.f.)
Summation
Runoff Factor
x Area (ac.)
Bioretention Basin Engineered Pervious Surface 0.10 0%0.006 256 0.0006
Natural Slope Natural Type 'B' Soil 0.14 0%0.059 2552 0.0082
Landscape Slope / Pad Semi-Pervious Surface 0.30 0%0.126 5499 0.0379
Roof/Hardscape/Driveway Impervious Surface 0.90 100%0.165 7170 0.1481
Total Total ATotal=0.355 15477 0.1948
Total Total ACheck=0.355 RFComposite-DMA=0.55
DMA Description DMA Type Runoff
Factor % Imper Area (ac.)Area (s.f.)
Summation
Runoff Factor
x Area (ac.)
Bioretention Basin Engineered Pervious Surface 0.10 0%0.005 218 0.0005
Natural Slope Natural Type 'B' Soil 0.14 0%0.122 5302 0.0170
Landscape Slope / Pad Semi-Pervious Surface 0.30 0%0.128 5572 0.0384
Roof/Hardscape/Driveway Impervious Surface 0.90 100%0.124 5390 0.1114
Total Total ATotal=0.378 0.378 0.1673
Total Total ACheck=0.378 RFComposite-DMA=0.44
DMA Description DMA Type Runoff
Factor % Imper Area (ac.)Area (s.f.)
Summation
Runoff Factor
x Area (ac.)
Driveway (ROW)Impervious Surface 0.90 100%0.017 750 0.0155
Total Total ATotal=0.017 750 0.0155
Total Total ACheck=0.017 RFComposite-DMA=0.90
DMA Description DMA Type Runoff
Factor % Imper Area (ac.)Area (s.f.)
Summation
Runoff Factor
x Area (ac.)
Pavement (Adams Street)Impervious Surface 0.90 100%0.036 1558 0.0322
Total Total ATotal=0.036 1558 0.0322
Total Total ACheck=0.036 RFComposite-DMA=0.90
Note: DMA5 implements Greet Street design elements including impervious dispersion to pervious surface at edge of pavement.
Note: Roof/Hardscape/Driveway in table are projected impervious area for Planning purposes. Actual areas may vary and require
adjustment to bioretention basin sizes during building permit phase.
DMA 3-PR
DMA 2-PR
DMA 1-PR
DMA 4-PR (DeMinimis, 250 s.f. per Lot Driveway Entrance)
DMA 5-PR (Adams Street Widening Opposite Side of Project)
ATTACHMENT 1c
FORM I-7 & I-8
ATTACHMENT 1C
FORMS I-7, I-8 & I-9
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.
Estimated Toilet and Urinal Flushing for 36 hours is: 1.24* 20*1.5=37 cubic feet
(residential total use per resident per day or 24 hours is 9.3 gallon or 1.24 cubic feet, estimated users on site is
20)
Estimated Landscape Irrigation Demand is : 196*0.60=124 cubic feet
(Assuming Hydrozone-Moderate Planter Water Use, 36 Hour Planning Level, demand is at 1470 gallon or 196
cubic feet/ acre)
Total Demand: 37+124 =161 for 36 hours or 107 for 24 hours
3. Calculate the DCV using worksheet B-2.1.
739 cubic feet for 24 hours
3a. Is the 36 hour demand greater
than or equal to the DCV?
Yes I Noc=>
~
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.
3b. Is the 36 hour demand greater than
0.25DCV but less than the full DCV?
Yes I Noc=>
,{J
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.
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.
3c. Is the 36 hour demand
less than 0.25DCV?
Yes
Harvest and use is
considered to be
infeasible.
Appendix I: Forms and Checklists
I-3 February 2016
Categorization of Infiltration Feasibility
Condition
Form I-8
Part 1 - Full Infiltration Feasibility Screening Criteria
Would infiltration of the full design volume be feasible from a physical perspective without any undesirable
consequences that cannot be reasonably mitigated?
Criteria Screening Question Yes No
1
Is the estimated reliable infiltration rate below proposed
facility locations greater than 0.5 inches per hour? The response
to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.2 and Appendix
D.
Provide basis:
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability.
2
Can infiltration greater than 0.5 inches per hour be allowed
without increasing risk of geotechnical hazards (slope stability,
groundwater mounding, utilities, or other factors) that cannot
be mitigated to an acceptable level? The response to this
Screening Question shall be based on a comprehensive evaluation of
the factors presented in Appendix C.2.
Provide basis:
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability.
NO
Per form I-9 the design infiltration rate is 0.44 in/hr which is less than 0.50 in/hr.
YES
Appendix I: Forms and Checklists
I-4 February 2016
Form I-8 Page 2 of 4
Criteri
a Screening Question Yes No
3
Can infiltration greater than 0.5 inches per hour be allowed
without increasing risk of groundwater contamination (shallow
water table, storm water pollutants or other factors) that cannot
be mitigated to an acceptable level? The response to this
Screening Question shall be based on a comprehensive evaluation of
the factors presented in Appendix C.3.
Provide basis:
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability.
4
Can infiltration greater than 0.5 inches per hour be allowed
without causing potential water balance issues such as change
of seasonality of ephemeral streams or increased discharge of
contaminated groundwater to surface waters? The response to
this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.3.
Provide basis:
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability.
Part 1
Result
*
If all answers to rows 1 - 4 are “Yes” a full infiltration design is potentially feasible.
The feasibility screening category is Full Infiltration
If any answer from row 1-4 is “No”, infiltration may be possible to some extent but
would not generally be feasible or desirable to achieve a “full infiltration” design.
Proceed to Part 2
*To be completed using gathered site information and best professional judgment considering the definition of MEP in
the MS4 Permit. Additional testing and/or studies may be required by the City to substantiate findings.
YES
YES
PROCEED TO
PART 2
Appendix I: Forms and Checklists
I-5 February 2016
Form I-8 Page 3 of 4
Part 2 – Partial Infiltration vs. No Infiltration Feasibility Screening Criteria
Would infiltration of water in any appreciable amount be physically feasible without any negative
consequences that cannot be reasonably mitigated?
Criteria Screening Question Yes No
5
Do soil and geologic conditions allow for infiltration in any
appreciable rate or volume? The response to this Screening
Question shall be based on a comprehensive evaluation of the
factors presented in Appendix C.2 and Appendix D.
Provide basis:
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates.
6
Can Infiltration in any appreciable quantity be allowed
without increasing risk of geotechnical hazards (slope
stability, groundwater mounding, utilities, or other factors)
that cannot be mitigated to an acceptable level? The response
to this Screening Question shall be based on a comprehensive
evaluation of the factors presented in Appendix C.2.
Provide basis:
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates.
YES
YES
Appendix I: Forms and Checklists
I-6 February 2016
Form I-8 Page 4 of 4
Criteria Screening Question Yes No
7
Can Infiltration in any appreciable quantity be allowed
without posing significant risk for groundwater related
concerns (shallow water table, storm water pollutants or other
factors)? The response to this Screening Question shall be based
on a comprehensive evaluation of the factors presented in
Appendix C.3.
Provide basis:
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates.
8
Can infiltration be allowed without violating downstream
water rights? The response to this Screening Question shall be
based on a comprehensive evaluation of the factors presented in
Appendix C.3.
Provide basis:
Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative
discussion of study/data source applicability and why it was not feasible to mitigate low infiltration rates.
Part 2
Result*
If all answers from row 5-8 are yes then partial infiltration design is potentially feasible.
The feasibility screening category is Partial Infiltration.
If any answer from row 5-8 is no, then infiltration of any volume is considered to be
infeasible within the drainage area. The feasibility screening category is No Infiltration.
*To be completed using gathered site information and best professional judgment considering the definition of MEP in
the MS4 Permit. Additional testing and/or studies may be required by the City to substantiate findings.
YES
YES
PARTIAL
INFILTRATION
A
Factor Category
Suitability
Assessment
Factor Description Assigned
Weight (w)
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 = Ip
B Design
Level of pretreatment/
expected sediment loads
Redundancy/ resiliency
Compaction during construction
Design Safety Factor, SB = Ip
Combined Safety Factor, Stora1= SA x SB
Observed Infiltration Rate, inch/hr, K observed
( corrected for test-specific bias)
Design Infiltration Rate, in/hr, Kciesign = K observed / Srotal
Supporting Data
Briefly describe infiltration test and provide reference to test forms:
Please see the infiltration testing attached after this page.
0.5
0.25
0.25
Factor
Value (v)
Product (p) p
=wxv
1 0.25
1 0.25
1 0.25
1 0.25
1
1 0.5
3 0.75
2 0.5
2.75
2.75
1.2
0.44
Todd R. Wyland, Civil Engineer
PO Box 293622 Phelan, CA 92329
Phone: (760) 475-7371 email: toddinwrightwood@yahoo.com
Slope Stability Analyses * Percolation & Compaction Testing * Soil Reports
September 14, 2015
Mr. Henry Olivier Project No: 1471
4370 Hallmark Drive, Suite 101
San Bernardino, CA 92407
SUBJECT: Infiltration Testing
NE Corner of Hoover & Adams Street
Carlsbad, California
REFERENCES: 1. Response to City of Carlsbad Geotechnical Plan Check Comments
Prepared By Todd Wyland, Project No: 147G, July 24, 2015
Dear Mr. Olivier:
2. Update to Preliminary Geotechnical Engineering Study Report
Prepared By Todd Wyland, Project No: 147G, April 10, 2014
3. Preliminary Geotechnical Engineering Study Report
Henry's Lots Located at NE Corner of Hoover & Adams Street
Carlsbad, California, Report Dated June 22, 2001
Prepared By Geotechnical Solutions, Inc., Project No. G-1845-06
As requested, I have performed an infiltration test on each of the three subject parcels, at the
planned infiltration trench location and depth. The tests were performed using ELE Model 25-
0660 double ring infiltrometers with Mariotte tubes to maintain constant head according to
ASTM D 3385.
The purpose of the infiltration testing was to provide appropriate infiltration test rate data for
design and to determine if the proposed infiltration trench locations are geotechnically feasible.
Infiltration Testing
Carlsbad Ocean Estates
Procedure:
September 14, 2015
A backhoe was utilized to excavate three test trenches, approximately 10 feet deep. The
exposed materials and conditions were confirmed to be as described in Reference No. 3.
The rings were carefully set, then presoaked by filling the rings with water to at least 8 inches.
Based upon the measured drop over two 30-minute time intervals during presoak, the testing
proceeded with 20-minute time intervals. Volume determinations and height readings were in
centimeters and converted to inches in the infiltration rate calculations. The test pits were
backfilled upon completion.
Results:
The test results are included on the attached Infiltration Test Data Sheets. The resulting
Infiltration rates vs. time for each inner ring are plotted on the attached Chart. The most
conservative stabilized infiltration test rate was 1.2 inches/hour.
Cone I usions:
Based upon the sandstone conditions encountered and the results of the subject infiltration
tests, it is my opinion that the proposed infiltration trenches are feasible from a geotechnical
standpoint.
Groundwater or evidence of previous shallow groundwater was not encountered and the depth
to groundwater beneath the Site was estimated to be about 60 feet (sea level). Therefore,
both the depth of permeable soil beneath the proposed infiltration trenches and the separation
to the historical high water depth exceed the standard minimums of 5 and -1 0 feet, respectively.
The proposed infiltration trenches will not adversely affect the adjacent properties.
I trust that this is sufficient for your needs at this time. If there any questions, please do not
hesitate to contact me .
Respectfully submitted,
<-~~~~~~EJ
Todd R. Wyland, RCE 60618
Attachments: Test Location Map
Infiltration Test Data Sheets (3)
Chart
2
--EAN ESTATES
-CARLSBAD OC d Adams Streets
-
f Hoover an NE Corner o I b d California Cars a ,
Test location Map
ffi ti 7'"'/ I = JU
DOUBLE RING INFILTROMETER TEST DATA (ASTM D 3385) Test No: IT-1 (sheet 1 of 1)
Ring Data Marriotte Tube
CARLSBAD OCEAN ESTATES Water
NE Corner of Hoover and Adams Streets Area, A, Depth No. Vol., V,
Carlsbad, California (cm2) {in) {cc/cm)
Inner Ring (12" ID): 729.7 4.5 1 {3,000 cc) 53.52
Test By: Todd Wyland I uses Class: (SP-SM) Annular Space (24" outer ring): 2189.0 4.5 2 (10,000 cc} 167.53
Depth to Water: 60' (approx) Penetration of Rings into Soil (in): Inner: 3 Outer: 3
Date of Test: 9/2/2015 I Water Source: Tank Filled From Fire Hydrant (water warmer than ground)
Constant Head Maintanied by Using: Marriotte Tubes
Test Location: Parcel 3
Test Elevation: 60 ft (approx)
Time Time l:lT (min)
Interval (hr:min) Total
1-Start 9:00 20
End 9:20 20
2-Start 9:20 20
End 9:40 40
3 -Start 9:40 20
End 10:00 60
4 -Start 10:00 20
End 10:20 80
5 -Start 10:20 20
End 10:40 100
6 -Start 10:45 20
End 11:05 120
7 -Start 11:05 20
End 11:25 140
8-Start 11:25 20
End 11:45 160
9 -Start 11:45 20
End 12:05 180
LO -Start 12:10 30
End 12:40 210
Ll -Start 12:40 30
End 1:10 240
L2 -Start 1:10 15
End 1:25 255
Inner Ring
Elev. H l:lH Qf*
(cm) (cm) (cc)
58.3 8.2
50.1 438.9
50.1 9.8
40.3 524.5
40.3 10.7
29.6 572.7
29.6 12.9
16.7 690.4
16.7 13.2
3.5 706.5
58.3 13.4
44.9 717.2
44.9 14.1
30.8 754.6
30.8 14.2
16.6 760.0
16.6 14.1
2.5 754.6
58.3 21.7
36.6 1161.4
36.6 21.7
14.9 1161.4
14.9 10.8
4.1 578.0
* Flow, Qf = ~H x Vr
** Infiltration Rate, I= (Qf/Ar)/~t
Annular Ring Infiltration Rate
I**
Elev. H l:lH Qf* Inner Outer
(cm) (cm) (cc) in/hr in/hr
58.3 8.5 0.71 0.77
49.8 1424.0
49.8 10.0 0.85 0.90
39.8 1675.3
39.8 10.5 0.93 0.95
29.3 1759.1
29.3 13.1 1.12 1.18
16.2 2194.6
16.2 13.3 1.14 1.20
2.9 2228.1
58.3 13.8 1.16 1.25
44.5 2311.9
44.5 14.4 1.22 1.30
30.1 2412.4
30.1 14.3 1.23 1.29
15.8 2395.7
15.8 14.1 1.22 1.27
1.7 2362.2
58.3 22.1 1.25 1.33
36.2 3702.4
36.2 21.9 1.25 1.32
14.3 3668.9
14.3 10.7 1.25 1.29
3.6 1792.6
Remarks
Cool, Partly Cloudy
No Wind
Warm and Sunny
Refilled Tubes
Refilled Tubes
DOUBLE RING INFILTROMETER TEST DATA (ASTM D 3385) Test No: IT-2 (sheet 1 of 1)
Ring Data Marriotte Tube
CARLSBAD OCEAN ESTATES Water
NE Corner of Hoover and Adams Streets Area, Ar Depth No. Vol., Vr
Carlsbad, California (cm2) (in) (cc/cm)
Inner Ring (12" ID): 729.7 5 1 (3,000 cc) 53.52
Test By: Todd Wyland I USCS Class: {SP-SM) Annular Space (24"1D outer ring): 2189 5 2 (10,000 cc) 167.53
Depth to Water: 60' (approx)! Penetration of Rings into Soil (in}: Inner: 3 Outer: 3
Date of Test: 9/2/2015 I Water Source: Tank Filled From Fire Hydrant (water warmer than ground)
Constant Head Maintanied by Using: Marriotte Tubes
Test Location: Parcel 2
Test Elevation: 57 ft (approx)
Time Time [ff (min)
Interval (hr:min) Total
1-Start 10:10 20
End 10:30 20
2 -Start 10:30 20
End 10:50 40
3 -Start 10:50 20
End 11:10 60
4 -Start 11:10 20
End 11:30 80
5 -Start 11:30 20
End 11:50 100
6 -Start 11:55 20
End 12:15 120
7 -Start 12:15 20
End 12:35 140
8 -Start 12:35 20
End 12:55 160
9 -Start 12:55 20
End 1:15 180
.0 -Start 1:20 30
End 1:50 210
.1-Start 1:50 30
End 2:20 240
.2 -Start 2:20 15
End 2:35 255
Inner Ring
Elev. H D.H Qf*
(cm) (cm) (cc)
58.3 7.6
50.7 406.8
50.7 9.6
41.1 513.8
41.1 10.5
30.6 562.0
30.6 11.4
19.2 610.1
19.2 12.2
7.0 652.9
58.3 13.1
45.2 701.1
45.2 13.6
31.6 727.9
31.6 13.8
17.8 738.6
17.8 13.8
4.0 738.6
58.3 20.8
37.5 1113.2
37.5 21.0
16.5 1123.9
16.5 10.4
6.1 556.6
* Flow, Qf= ~H xVr
** Infiltration Rate, I= (Qf/Ar)/t::..t
Annular Ring Infiltration
Rate I**
Elev. H D.H Qf* Inner Outer
(cm) (cm) (cc) in/hr in/hr
58.3 7.9 0.66 0.71
50.4 1323.5
50.4 9.6 0.83 0.87
40.8 1608.3
40.8 10.3 0.91 0.93
30.5 1725.6
30.5 11.4 0.99 1.03
19.1 1909.8
19.1 12.3 1.06 1.11
6.8 2060.6
58.3 12.7 1.13 1.15
45.6 2127.6
45.6 13.4 1.18 1.21
32.2 2244.9
32.2 13.5 1.20 1.22
18.7 2261.7
18.7 13.6 1.20 1.23
5.1 2278.4
58.3 20.3 1.20 1.22
38.0 3400.9
38.0 20.5 1.21 1.24
17.5 3434.4
17.5 10.2 1.20 1.23
7.3 1708.8
Remarks
Warm and Sunny
No Wind
Refilled Tubes
Refilled Tubes
DOUBLE RING INFILTROMETER TEST DATA (ASTM D 3385) Test No: IT-3 (sheet 1 of 1)
Ring Data Marriotte Tube
CARLSBAD OCEAN ESTATES Area, Water
NE Corner of Hoover and Adams Streets Ar Depth No. Vol., Vr
Carlsbad, CA (cm2) (in) (cc/cm)
Inner Ring {12" ID): 729.7 4.5 1 (3,000 cc) 53.52
Test By: Todd Wyland I uses Class: (SP-SM) ,nnular Space (24"1D outer ring): 2189 4.5 2 (10,000 cc) 167.53
Depth to Water: 60' (approx~ Penetration of Rings into Soil (in): Inner: 2.5 Outer: 2.5
Date of Test: 9/2/2015 I Water Source: Tank Filled From Fire Hydrant {water warmer than ground)
Constant Head Maintanied by Using: Marriotte Tubes
Test Location: Parcel 1
Test Elevation: 61 ft (approx)
Time Time AT (min)
Interval (hr:min) Total
1-Start 1:45 20
End 2:05 20
2 -Start 2:05 20
End 2:25 40
3 -Start 2:25 20
End 2:45 60
4-Start 2:45 20
End 3:05 80
5 -Start 3:05 20
End 3:25 100
6-Start 3:30 20
End 3:50 120
7 -Start 3:50 20
End 4:10 140
8-Start 4:10 20
End 4:30 160
9-Start 4:30 20
End 4:50 180
10-Start 4:55 30
End 5:25 210
11-Start 5:25 30
End 5:55 240
tl.2-Start 5:55 15
End 6:10 255
Inner Ring
Elev. H AH Qf*
(cm) (cm) (cc)
58.3 8.5
49.8 454.9
49.8 10.3
39.5 551.3
39.5 11.5
28.0 615.5
28.0 12.3
15.7 658.3
15.7 13.2
2.5 706.5
58.3 13.8
44.5 738.6
44.5 14.6
29.9 781.4
29.9 14.7
15.2 786.7
15.2 14.8
0.4 792.1
58.3 23.1
35.2 1236.3
35.2 22.8
12.4 1220.3
12.4 11.4
1.0 610.1
* Flow, Qf = /lH x Vr
** Infiltration Rate, I= (Qf/Ar)/llt
Annular Ring Infiltration
R:ati> I**
Elev. H AH Qf* Inner Outer
(cm) (cm) (cc) in/hr in/hr
58.3 8.6 0.74 0.78 49.7 1440.8
49.7 10.2 0.89 0.92 39.S 1708.8
39.S 11.4 1.00 1.03 28.1 1909.8
28.1 12.3 1.07 1.11 15.8 2060.6
15.8 12.9
2.9 2161.1 1.14 1.17
58.3 14.0 1.20 1.27 44.3 2345.4
44.3 14.7
29.6 2462.7 1.26 1.33
29.6 14.6 1.27 1.32 15.0 2445.9
15.0 14.8 1.34 0.2 1.28 2479.4
58.3 22.5
35.8 3769.4 1.33 1.36
35.8 22.7
13.1 3802.9 1.32 1.37
13.1 11.3
1.8 1893.1 1.32 1.36
Remarks
Warm and Sunny
No Wind
Refilled Tubes
Refilled Tubes
ATTACHMENT 1e
POLLUTANT CONTROL BMP
DESIGN WORKSHEETS
Home ..,., 85th Percentile Rainfa ll .:i. Sign In
[ 0 Details ] I 0 8 Basemap ~ Share lie" Print ..,. I ~ Measure [ ..... F_in_d_a_d_d_re_s_s_o_r_p_l_ac_e ____________ lLQ.__,]
0 □
Legend
·-·-·-
85th Percentile Rainfall
Contact Us
◄
0 0.3 0 .6mi
Aqua
Hed1onda
Lagoon
~
~,<)
t ~
L gobnd
C liforn1u
R sort
• 168 ft C
o.,,.
Frost
Evans Point
Crossings t
C,rla d
Golf Cour
od a agement, Es<i, ERE, Garmin, ...
'
t?
i-e
Category #Description i ii iii iv v vi vii viii ix x Units
1 Drainage Basin ID or Name DMA 1 DMA 2 DMA 3 DMA 4 DMA 5 unitless
2 85th Percentile 24-hr Storm Depth 0.59 0.59 0.59 0.59 0.59 inches
3 Impervious Surfaces Not Directed to Dispersion Area (C=0.90)7,305 7,170 5,390 750 1,558 sq-ft
4 Semi-Pervious Surfaces Not Serving as Dispersion Area (C=0.30)5,803 5,605 5,640 sq-ft
5 Engineered Pervious Surfaces Not Serving as Dispersion Area (C=0.10)150 150 150 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)2,825 2,552 5,302 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 No No No No No No 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 16,083 15,477 16,482 750 1,558 0 0 0 0 0 sq-ft
23 Initial Runoff Factor for Standard Drainage Areas 0.54 0.55 0.44 0.90 0.90 0.00 0.00 0.00 0.00 0.00 unitless
24 Initial Runoff Factor for Dispersed & Dispersion Areas 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 unitless
25 Initial Weighted Runoff Factor 0.54 0.55 0.44 0.90 0.90 0.00 0.00 0.00 0.00 0.00 unitless
26 Initial Design Capture Volume 427 419 357 33 69 0 0 0 0 0 cubic-feet
27 Total Impervious Area Dispersed to Pervious Surface 0 0 0 0 0 0 0 0 0 0 sq-ft
28 Total Pervious Dispersion Area 0 0 0 0 0 0 0 0 0 0 sq-ft
29 Ratio of Dispersed Impervious Area to Pervious Dispersion Area n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a ratio
30 Adjustment Factor for Dispersed & Dispersion Areas 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 ratio
31 Runoff Factor After Dispersion Techniques 0.54 0.55 0.44 0.90 0.90 n/a n/a n/a n/a n/a unitless
32 Design Capture Volume After Dispersion Techniques 427 419 357 33 69 0 0 0 0 0 cubic-feet
33 Total Tree Well Volume Reduction 0 0 0 0 0 0 0 0 0 0 cubic-feet
34 Total Rain Barrel Volume Reduction 0 0 0 0 0 0 0 0 0 0 cubic-feet
35 Final Adjusted Runoff Factor 0.54 0.55 0.44 0.90 0.90 0.00 0.00 0.00 0.00 0.00 unitless
36 Final Effective Tributary Area 8,685 8,512 7,252 675 1,402 0 0 0 0 0 sq-ft
37 Initial Design Capture Volume Retained by Site Design Elements 0 0 0 0 0 0 0 0 0 0 cubic-feet
38 Final Design Capture Volume Tributary to BMP 427 419 357 33 69 0 0 0 0 0 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 iii iv v vi vii viii ix x Units
1 Drainage Basin ID or Name DMA 1 DMA 2 DMA 3 DMA 4 DMA 5 -----unitless
2 85th Percentile Rainfall Depth 0.59 0.59 0.59 0.59 0.59 -----inches
3 Predominant NRCS Soil Type Within BMP Location B B B B B unitless
4 Is proposed BMP location Restricted or Unrestricted for Infiltration Activities? Unrestricted Unrestricted Unrestricted Unrestricted Unrestricted unitless
5 Nature of Restriction n/a n/a n/a n/a n/a unitless
6 Do Minimum Retention Requirements Apply to this Project?Yes Yes Yes No No Yes Yes Yes Yes Yes yes/no
7 Are Habitable Structures Greater than 9 Stories Proposed?No No No yes/no
8 Has Geotechnical Engineer Performed an Infiltration Analysis?Yes Yes Yes yes/no
9 Design Infiltration Rate Recommended by Geotechnical Engineer 0.440 0.440 0.440 in/hr
10 Design Infiltration Rate Used To Determine Retention Requirements 0.440 0.440 0.440 0.200 0.200 -----in/hr
11 Percent of Average Annual Runoff that Must be Retained within DMA 40.0%40.0%40.0%0.0%0.0%-----percentage
12 Fraction of DCV Requiring Retention 0.32 0.32 0.32 0.00 0.00 -----ratio
13 Required Retention Volume 137 134 114 0 0 -----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 supplemental calculations demonstrating retention requirements are satisfied at the project-level.
False
Automated Worksheet B.2: Retention Requirements (V2.0)
Advanced
Analysis
Basic Analysis
Result
Attention!
Category #Description i ii iii iv v vi vii viii ix x
1 Drainage Basin ID or Name DMA 1 DMA 2 DMA 3 DMA 4 DMA 5 -----
2 Design Infiltration Rate Recommended 0.440 0.440 0.440 0.200 0.200 -----
3 Design Capture Volume Tributary to BMP 427 419 357 33 69 -----
4 Is BMP Vegetated or Unvegetated?Vegetated Vegetated Vegetated
5 Is BMP Impermeably Lined or Unlined?Unlined Unlined Unlined
6 Does BMP Have an Underdrain?Underdrain Underdrain Underdrain
7 Does BMP Utilize Standard or Specialized Media?Standard Standard Standard
8 Provided Surface Area 261 256 218
9 Provided Surface Ponding Depth 6 6 6
10 Provided Soil Media Thickness 18 18 18
11 Provided Gravel Thickness (Total Thickness)12 12 12
12 Underdrain Offset 3 3 3
13 Diameter of Underdrain or Hydromod Orifice (Select Smallest)6.00 6.00 6.00
14 Specialized Soil Media Filtration Rate
15 Specialized Soil Media Pore Space for Retention
16 Specialized Soil Media Pore Space for Biofiltration
17 Specialized Gravel Media Pore Space
18 Volume Infiltrated Over 6 Hour Storm 57 56 48 0 0 0 0 0 0 0
19 Ponding Pore Space Available for Retention 0.00 0.00 0.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00
20 Soil Media Pore Space Available for Retention 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05 0.05
21 Gravel Pore Space Available for Retention (Above Underdrain)0.00 0.00 0.00 0.40 0.40 0.40 0.40 0.40 0.40 0.40
22 Gravel Pore Space Available for Retention (Below Underdrain)0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40
23 Effective Retention Depth 2.10 2.10 2.10 0.00 0.00 0.00 0.00 0.00 0.00 0.00
24 Fraction of DCV Retained (Independent of Drawdown Time)0.24 0.24 0.24 0.00 0.00 0.00 0.00 0.00 0.00 0.00
25 Calculated Retention Storage Drawdown Time 6 6 6 0 0 0 0 0 0 0
26 Efficacy of Retention Processes 0.80 0.80 0.80 0.00 0.00 0.00 0.00 0.00 0.00 0.00
27 Volume Retained by BMP (Considering Drawdown Time)340 334 284 0 0 0 0 0 0 0
28 Design Capture Volume Remaining for Biofiltration 87 85 73 33 69 0 0 0 0 0
29 Max Hydromod Flow Rate through Underdrain 1.4948 1.4948 1.4948 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000
30 Max Soil Filtration Rate Allowed by Underdrain Orifice 247.42 252.25 296.22 0.00 0.00 0.00 0.00 0.00 0.00 0.00
31 Soil Media Filtration Rate per Specifications 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00 5.00
32 Soil Media Filtration Rate to be used for Sizing 5.00 5.00 5.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
33 Depth Biofiltered Over 6 Hour Storm 30.00 30.00 30.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
34 Ponding Pore Space Available for Biofiltration 1.00 1.00 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
35 Soil Media Pore Space Available for Biofiltration 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20
36 Gravel Pore Space Available for Biofiltration (Above Underdrain)0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40 0.40
37 Effective Depth of Biofiltration Storage 13.20 13.20 13.20 0.00 0.00 0.00 0.00 0.00 0.00 0.00
38 Drawdown Time for Surface Ponding 1 1 1 0 0 0 0 0 0 0
39 Drawdown Time for Effective Biofiltration Depth 2 2 2 0 0 0 0 0 0 0
40 Total Depth Biofiltered 43.20 43.20 43.20 0.00 0.00 0.00 0.00 0.00 0.00 0.00
41 Option 1 - Biofilter 1.50 DCV: Target Volume 130 128 109 50 104 0 0 0 0 0
42 Option 1 - Provided Biofiltration Volume 130 128 109 0 0 0 0 0 0 0
43 Option 2 - Store 0.75 DCV: Target Volume 65 64 54 25 52 0 0 0 0 0
44 Option 2 - Provided Storage Volume 65 64 54 0 0 0 0 0 0 0
45 Portion of Biofiltration Performance Standard Satisfied 1.00 1.00 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
46 Do Site Design Elements and BMPs Satisfy Annual Retention Requirements?Yes Yes Yes Yes Yes -----
47 Overall Portion of Performance Standard Satisfied (BMP Efficacy Factor)1.00 1.00 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
48 Deficit of Effectively Treated Stormwater 0 0 0 -33 -69 n/a n/a n/a n/a n/a
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
Low orifice:1 "Top orifice:1 "
Number:0 Number:0
Cg-low:0.61 Cg-low:0.61
invert elev:69.50 ft invert elev:69.50 ft
Middle orifice:1 "Emergency Inlet:
number of orif:0 Rim Elev:70.00 ft
Cg-middle:0.61 Area (SF=2)1.00 sq ft
invert elev:69.50 ft Circumference 4.00 ft
Elev H/D-low H/D-mid H/D-top Qlow-orif Qlow-weir Qtot-low Qmid-orif Qmid-weir Qtot-med Qtop-orif Qtop-weir Qtot-top Qemerg Qtot
(ft)---(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)
69.5 0.00 0.00 0.00 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
69.6 1.20 1.20 1.20 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
69.7 2.40 2.40 2.40 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
69.8 3.60 3.60 3.60 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
69.9 4.80 4.80 4.80 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
70.0 6.00 6.00 6.00 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
70.1 7.20 7.20 7.20 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.392 0.392
70.2 8.40 8.40 8.40 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.109 1.109
70.3 9.60 9.60 9.60 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2.038 2.038
70.4 10.80 10.80 10.80 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.096 3.096
70.5 12.00 12.00 12.00 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.461 3.461
Carlsbad Oceanview Estates
Basin PR-1-1
Stage Discharge Table
R:\0109-0001 Carlsbad Oceanview Estates - Olivier, Henry\Hyd\SWQMP\Calcs\0109-0001_Basin Storage-Outlet-Drawdown_Basin BF-3.xlsx
Elev (ft.)Area (s.f.) Area (ac.)
Elevation
(ft.)
Volume
(c.f.)
69.5 91 0.0021 69.5 0
69.6 103 0.0024 69.6 10
69.7 115 0.0026 69.7 21
69.8 129 0.0030 69.8 33
69.9 143 0.0033 69.9 46
70.0 157 0.0036 70.0 61
70.1 173 0.0040 70.1 78
70.2 189 0.0043 70.2 96
70.3 206 0.0047 70.3 116
70.4 223 0.0051 70.4 137
70.5 241 0.0055 70.5 160
Carlsbad Oceanview Estates
Basin PR-1-1
Stage Storage Table
R:\0109-0001 Carlsbad Oceanview Estates - Olivier, Henry\Hyd\SWQMP\Calcs\0109-0001_Basin Storage-Outlet-
Drawdown_Basin BF-3.xlsx
QSubdrain=0.011
Elevation (ft)QAVG (CFS)DV (CF)DT (HR)Total T (hrs)
69.5 0.011 10 0.2556 2.090
69.6 0.011 11 0.2877 1.835
69.7 0.011 12 0.3216 1.547
69.8 0.011 14 0.3575 1.226
69.9 0.011 15 0.3953 0.868
70.0 0.011 16 0.4350 0.473
70.1 0.207 18 0.0243 0.038
70.2 0.761 20 0.0072 0.013
70.3 1.584 21 0.0038 0.006
70.4 2.577 23 0.0025 0.003
70.5 3.289 0.0000 0.000
Carlsbad Oceanview Estates
Basin PR-1-1
Stage Drawdown Table
R:\0109-0001 Carlsbad Oceanview Estates - Olivier, Henry\Hyd\SWQMP\Calcs\0109-0001_Basin Storage-Outlet-
Drawdown_Basin BF-3.xlsx
Low orifice:1 "Top orifice:1 "
Number:0 Number:0
Cg-low:0.61 Cg-low:0.61
invert elev:64.50 ft invert elev:64.50 ft
Middle orifice:1 "Emergency Inlet:
number of orif:0 Rim Elev:65.00 ft
Cg-middle:0.61 Area (SF=2)1.00 sq ft
invert elev:64.50 ft Circumference 4.00 ft
Elev.H/D-low H/D-mid H/D-top Qlow-orif Qlow-weir Qtot-low Qmid-orif Qmid-weir Qtot-med Qtop-orif Qtop-weir Qtot-top Qemerg Qtot
(ft)---(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)
64.5 0.00 0.00 0.00 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
64.6 1.20 1.20 1.20 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
64.7 2.40 2.40 2.40 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
64.8 3.60 3.60 3.60 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
64.9 4.80 4.80 4.80 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
65.0 6.00 6.00 6.00 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
65.1 7.20 7.20 7.20 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.392 0.392
65.2 8.40 8.40 8.40 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.109 1.109
65.3 9.60 9.60 9.60 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2.038 2.038
65.4 10.80 10.80 10.80 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.096 3.096
65.5 12.00 12.00 12.00 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.461 3.461
Carlsbad Oceanview Estates
Basin PR-1-2
Stage Discharge Table
R:\0109-0001 Carlsbad Oceanview Estates - Olivier, Henry\Hyd\SWQMP\Calcs\0109-0001_Basin Storage-Outlet-Drawdown_Basin BF-3.xlsx
Elev (ft.)Area (s.f.) Area (ac.)
Elevation
(ft.)
Volume
(c.f.)
64.5 89 0.0020 64.5 0
64.6 101 0.0023 64.6 9
64.7 113 0.0026 64.7 20
64.8 126 0.0029 64.8 32
64.9 140 0.0032 64.9 45
65.0 155 0.0035 65.0 60
65.1 170 0.0039 65.1 76
65.2 186 0.0043 65.2 94
65.3 203 0.0047 65.3 114
65.4 220 0.0051 65.4 135
65.5 238 0.0055 65.5 158
Carlsbad Oceanview Estates
Basin PR-1-2
Stage Storage Table
R:\0109-0001 Carlsbad Oceanview Estates - Olivier, Henry\Hyd\SWQMP\Calcs\0109-0001_Basin Storage-Outlet-
Drawdown_Basin BF-3.xlsx
QSubdrain=0.010
Elevation QAVG (CFS)DV (CF)DT (HR)Total T (hrs)
64.5 0.010 9 0.2557 2.004
64.6 0.010 10 0.2827 1.748
64.7 0.010 12 0.3112 1.466
64.8 0.010 13 0.3413 1.155
64.9 0.010 14 0.3730 0.813
65.0 0.010 15 0.4063 0.440
65.1 0.206 16 0.0220 0.034
65.2 0.761 18 0.0065 0.012
65.3 1.584 19 0.0034 0.006
65.4 2.577 21 0.0022 0.002
65.5 3.289 0.0000 0.000
Carlsbad Oceanview Estates
Basin PR-1-2
Stage Drawdown Table
R:\0109-0001 Carlsbad Oceanview Estates - Olivier, Henry\Hyd\SWQMP\Calcs\0109-0001_Basin Storage-Outlet-
Drawdown_Basin BF-3.xlsx
Low orifice:1 "Top orifice:1 "
Number:0 Number:0
Cg-low:0.61 Cg-low:0.61
invert elev:67.50 ft invert elev:67.50 ft
Middle orifice:1 "Emergency Inlet:
number of orif:0 Rim Elev:68.00 ft
Cg-middle:0.61 Area (SF=2)1.00 sq ft
invert elev:67.50 ft Circumference 4.00 ft
Elev H/D-low H/D-mid H/D-top Qlow-orif Qlow-weir Qtot-low Qmid-orif Qmid-weir Qtot-med Qtop-orif Qtop-weir Qtot-top Qemerg Qtot
(ft)---(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)(cfs)
67.5 0.00 0.00 0.00 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
67.6 1.20 1.20 1.20 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
67.7 2.40 2.40 2.40 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
67.8 3.60 3.60 3.60 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
67.9 4.80 4.80 4.80 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
68.0 6.00 6.00 6.00 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
68.1 7.20 7.20 7.20 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.392 0.392
68.2 8.40 8.40 8.40 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.109 1.109
68.3 9.60 9.60 9.60 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 2.038 2.038
68.4 10.80 10.80 10.80 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.096 3.096
68.5 12.00 12.00 12.00 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 3.461 3.461
Carlsbad Oceanview Estates
Basin PR-1-3
Stage Discharge Table
R:\0109-0001 Carlsbad Oceanview Estates - Olivier, Henry\Hyd\SWQMP\Calcs\0109-0001_Basin Storage-Outlet-Drawdown_Basin BF-3.xlsx
Elev (ft.)Area (s.f.) Area (ac.)
Elevation
(ft.)
Volume
(c.f.)
67.5 43 0.0010 67.5 0
67.6 51 0.0012 67.6 5
67.7 60 0.0014 67.7 10
67.8 70 0.0016 67.8 17
67.9 80 0.0018 67.9 24
68.0 91 0.0021 68.0 33
68.1 103 0.0024 68.1 43
68.2 116 0.0027 68.2 54
68.3 129 0.0030 68.3 66
68.4 143 0.0033 68.4 79
68.5 158 0.0036 68.5 94
Carlsbad Oceanview Estates
Basin PR-1-3
Stage Storage Table
R:\0109-0001 Carlsbad Oceanview Estates - Olivier, Henry\Hyd\SWQMP\Calcs\0109-0001_Basin Storage-Outlet-
Drawdown_Basin BF-3.xlsx
QSubdrain=0.005
Elevation QAVG (CFS)DV (CF)DT (HR)Total T (hrs)
69.5 0.005 5 0.2630 1.857
69.6 0.005 6 0.3109 1.594
69.7 0.005 7 0.3629 1.283
69.8 0.005 8 0.4188 0.920
69.9 0.005 9 0.4788 0.501
70.0 0.201 10 0.0134 0.022
70.1 0.756 11 0.0040 0.009
70.2 1.578 12 0.0022 0.005
70.3 2.572 14 0.0015 0.003
70.4 3.284 15 0.0013 0.001
70.5 1.736 0.0000 0.000
Carlsbad Oceanview Estates
Basin PR-1-3
Stage Drawdown Table
R:\0109-0001 Carlsbad Oceanview Estates - Olivier, Henry\Hyd\SWQMP\Calcs\0109-0001_Basin Storage-Outlet-
Drawdown_Basin BF-3.xlsx
STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST
How to use this worksheet (also see instructions in Section G of the WQMP Template):
1. Review Column 1 and identify which of these potential sources of stormwater pollutants apply to your site. Check each box that applies.
2. Review Column 2 and incorporate all of the corresponding applicable BMPs in your WQMP Exhibit.
3. Review Columns 3 and 4 and incorporate all of the corresponding applicable permanent controls and operational BMPs in your WQMP. Use the
format shown in Table G. lon page 23 of this WQMP Template. Describe your specific BMPs in an accompanying narrative, and explain any
special conditions or situations that required omitting BMPs or substituting alternative BMPs for those shown here.
IF THESE SOURCES WILL BE ... THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE ON THE PROJECT SITE ...
1 2 3 4
Potential Sources of Permanent Controls-Show on Permanent Controls-List in WQMP Operational BMPs-lnclude in WQMP
Runoff Pollutants WQMP Drawings Table and Narrative Table and Narrative
0 A. On-site storm drain 0 Locations of inlets. 0 Mark all inlets with the words 0 Maintain and periodically repaint or
inlets "Only Rain Down the Storm replace inlet markings.
Drain" or similar. Catch Basin 0 Provide stormwater pollution Markers may be available from the prevention information to new site Riverside County Flood Control owners, lessees, or operators. and Water Conservation District,
call 951.955.1200 to verify. 0 See applicable operational BMPs in
Fact Sheet SC-44, "Drainage System
Maintenance," in the CASQA
Stormwater Quality Handbooks at
www.cabm12handbooks.com
0 Include the following in lease
agreements: "Tenant shall not allow
anyone to discharge anything to storm
drains or to store or deposit materials
so as to create a potential discharge to
storm drains."
□ B. Interior floor drains □ State that interior floor drains and □ Inspect and maintain drains to prevent
and elevator shaft sump elevator shaft sump pumps will be blockages and overflow.
pumps plumbed to sanitary sewer.
□ C. Interior parking □ State that parking garage floor □ Inspect and maintain drains to prevent
garages drains will be plumbed to the blockages and overflow.
sanitary sewer.
STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST
IF THESE SOURCES WILL BE ... THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE ON THE PROJECT SITE ...
1 2 3 4
Potential Sources of Permanent Controls-Show on Permanent Controls-List in WQMP Operational BMPs-lnclude in WQMP
Runoff Pollutants WQMP Drawings Table and Narrative Table and Narrative
0 D1. Need for future 0 Note building design features that 0 Provide Integrated Pest Management
indoor & structural pest discourage entry of pests. information to owners, lessees, and
control operators.
0 D2. Landscape/ 0 Show locations of native trees or State that final landscape plans will 0 Maintain landscaping using minimum
Outdoor Pesticide Use areas of shrubs and ground cover to accomplish all of the following. or no pesticides.
be undisturbed and retained. 0 Preserve existing native trees, 0 See applicable operational BMPs in 0 Show self-retaining landscape shrubs, and ground cover to the "What you should know
areas, if any. maximum extent possible. for ..... Landscape and Gardening" at
0 Show stormwater treatment and 0 Design landscaping to minimize http://rcflood.org/ stormwater/Error!
hydrograph modification irrigation and runoff, to promote H yperlink reference not valid.
management BMPs. (See surface infiltration where Provide 1PM information to new
instructions in Chapter 3, Step 5 appropriate, and to minimize the 0 owners, lessees and operators.
and guidance in Chapter 5.) use of fertilizers and pesticides that
can contribute to stormwater
0 pollution.
Where landscaped areas are used to
retain or detain stormwater, specify
plants that are tolerant of saturated
0 soil conditions.
Consider using pest-resistant
0 plants, especially adjacent to
hardscape.
To insure successful establishment,
select plants appropriate to site
soils, slopes, climate, sun, wind,
rain, land use, air movement,
ecological consistency, and plant
interactions.
STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST
IF THESE SOURCES WILL BE ... THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE ON THE PROJECT SITE ...
1 2 3 4
Potential Sources of Permanent Controls-Show on Permanent Controls-List in WQMP Operational BMPs-lnclude in WQMP
Runoff Pollutants WQMP Drawings Table and Narrative Table and Narrative
□ E. Pools, spas, ponds, 0 Show location of water feature and If the Co-Perrnittee requires pools 0 See applicable operational BMPs in
decorative fountains, a sanitary sewer cleanout in an to be plumbed to the sanitary "Guidelines for Maintaining Your
and other water accessible area within 10 feet. sewer, place a note on the plans Swimming Pool, Jacuzzi and Garden
features. (Exception: Public pools must be and state in the narrative that this Fountain" at
plumbed according to County connection will be made according http://rcflood.org/ stormwater/
Department of Environmental to local requirements.
Health Guidelines.)
□ F. Food service □ For restaurants, grocery stores, and □ Describe the location and features □ See the brochure, "The Food Service
other food service operations, show of the designated cleaning area. Industry Best Management Practices for:
location (indoors or in a covered □ Describe the items to be cleaned in Restaurants, Grocery Stores,
area outdoors) of a floor sink or this facility and how it has been Delicatessens and Bakeries" at
other area for cleaning floor mats, sized to insure that the largest http://rcflood.org/ stormwater/
containers, and equipment. items can be accommodated. Provide this brochure to new site
□ On the drawing, show a note that owners, lessees, and operators.
this drain will be connected to a
grease interceptor before
discharging to the sanitary sewer.
□ G. Refuse areas □ Show where site refuse and □ State how site refuse will be □ State how the following will be
recycled materials will be handled handled and provide supporting implemented:
and stored for pickup. See local detail to what is shown on plans. Provide adequate number of municipal requirements for sizes □ State that signs will be posted on or receptacles. Inspect receptacles and other details of refuse areas. near dumpsters with the words "Do regularly; repair or replace leaky
□ If dumpsters or other receptacles not dump hazardous materials receptacles. Keep receptacles covered.
are outdoors, show how the here" or similar. Prohibit/prevent dumping of liquid or
designated area will be covered, hazardous wastes. Post "no hazardous
graded, and paved to prevent run-materials" signs. Inspect and pick up
on and show locations of berms to litter daily and clean up spills
prevent runoff from the area. immediately. Keep spill control
□ Any drains from dumpsters, materials available on-site. See Fact
compactors, and tallow bin areas Sheet SC-34, "Waste Handling and
shall be connected to a grease Disposal" in the CASQA Stormwater
removal device before discharge to Quality Handbooks at
sanitary sewer. www.cabmphandbooks.com
STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST
IF THESE SOURCES WILL BE ... THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE ON THE PROJECT SITE ...
1 2 3 4
Potential Sources of Permanent Controls-Show on Permanent Controls-List in WQMP Operational BMPs-lnclude in WQMP
Runoff Pollutants WQMP Drawings Table and Narrative Table and Narrative
□ H. Industrial processes. □ Show process area. □ If industrial processes are to be □ See Fact Sheet SC-10, "Non-
located on site, state: "All process Stormwater Discharges" in the
activities to be performed indoors. CASQA Stormwater Quality
No processes to drain to exterior or Handbooks at
to storm drain system." www.cabm1,2handbooks.com
See the brochure "Industrial &
Commercial Facilities Best Management
Practices for: Industrial, Commercial
Facilities" at
http://rcflood.org/ stormwater/
STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST
IF THESE SOURCES WILL BE ... THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE ON THE PROJECT SITE ...
1 2 3 4
Potential Sources of Permanent Controls-Show on Permanent Controls-List in WQMP Operational BMPs-lnclude in WQMP
Runoff Pollutants WQMP Drawings Table and Narrative Table and Narrative
□ I. Outdoor storage of □ Show any outdoor storage areas, Include a detailed description of □ See the Fact Sheets SC-31, "Outdoor
equipment or materials. including how materials will be materials to be stored, storage Liquid Container Storage" and SC-33,
(See rows J and K for covered. Show how areas will be areas, and structural features to "Outdoor Storage of Raw Materials "
source control graded and bermed to prevent run-prevent pollutants from entering in the CASQA Stormwater Quality
measures for vehicle on or run-off from area. storm drains. Handbooks at
cleaning, repair, and □ Storage of non-hazardous liquids Where appropriate, reference www.cabmphandbooks.com
maintenance.) shall be covered by a roof and/ or documentation of compliance with
drain to the sanitary sewer system, the requirements of Hazardous
and be contained by berms, dikes, Materials Programs for:
liners, or vaults. ■ Hazardous Waste Generation
□ Storage of hazardous materials and Hazardous Materials Release ■ wastes must be in compliance with Response and Inventory the local hazardous materials
ordinance and a Hazardous ■ California Accidental Release
Materials Management Plan for the (CalARP)
site. ■ Aboveground Storage Tank
■ Uniform Fire Code Article 80
Section 103(b) & (c) 1991
■ Underground Storage Tank
www.cchealth.org Lgroups Lhazmat
L
STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST
IF THESE SOURCES WILL BE ... THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE ON THE PROJECT SITE ...
1 2 3 4
Potential Sources of Permanent Controls-Show on Permanent Controls-List in WQMP Operational BMPs-lnclude in WQMP
Runoff Pollutants WQMP Drawings Table and Narrative Table and Narrative
□ J. Vehicle and □ Show on drawings as appropriate: □ If a car wash area is not provided, Describe operational measures to
Equipment Cleaning (1) Commercial/industrial facilities describe any measures taken to implement the following (if
having vehicle/ equipment cleaning discourage on-site car washing and applicable):
needs shall either provide a explain how these will be enforced. □ Washwater from vehicle and
covered, bermed area for washing equipment washing operations shall
activities or discourage not be discharged to the storm drain
vehicle/ equipment washing by system. Refer to "Outdoor Cleaning
removing hose bibs and installing Activities and Professional Mobile Service
signs prohibiting such uses. Providers" for many of the Potential
(2) Multi-dwelling complexes shall Sources of Runoff Pollutants categories
have a paved, bermed, and covered below. Brochure can be found at
car wash area (unless car washing http://rcflood.org/ stormwater/
is prohibited on-site and hoses are □Car dealerships and similar may
provided with an automatic shut-rinse cars with water only.
off to discourage such use).
(3) Washing areas for cars, vehicles,
and equipment shall be paved,
designed to prevent run-on to or
runoff from the area, and plumbed
to drain to the sanitary sewer.
(4) Commercial car wash facilities
shall be designed such that no
runoff from the facility is
discharged to the storm drain
system. Wastewater from the
facility shall discharge to the
sanitary sewer, or a wastewater
reclamation system shall be
installed.
STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST
IF THESE SOURCES WILL BE ... THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE ON THE PROJECT SITE ...
1 2 3 4
Potential Sources of Permanent Controls-Show on Permanent Controls-List in WQMP Operational BMPs-lnclude in WQMP
Runoff Pollutants WQMP Drawings Table and Narrative Table and Narrative
□ K. Vehicle/Equipment □ Accommodate all vehicle □ State that no vehicle repair or In the Stormwater Control Plan, note
Repair and equipment repair and maintenance maintenance will be done outdoors, that all of the following restrictions
Maintenance indoors. Or designate an outdoor or else describe the required apply to use the site:
work area and design the area to features of the outdoor work area. □ No person shall dispose of, nor permit prevent run-on and runoff of □ State that there are no floor drains the disposal, directly or indirectly of stormwater. or if there are floor drains, note the vehicle fluids, hazardous materials, or
□ Show secondary containment for agency from which an industrial rinsewater from parts cleaning into
exterior work areas where motor waste discharge permit will be storm drains.
oil, brake fluid, gasoline, diesel obtained and that the design meets □ No vehicle fluid removal shall be fuel, radiator fluid, acid-containing that agency's requirements. performed outside a building, nor on batteries or other hazardous □ State that there are no tanks, asphalt or ground surfaces, whether materials or hazardous wastes are
used or stored. Drains shall not be containers or sinks to be used for inside or outside a building, except in
installed within the secondary parts cleaning or rinsing or, if there such a manner as to ensure that any
are, note the agency from which an spilled fluid will be in an area of containment areas. industrial waste discharge permit secondary containment. Leaking
□ Add a note on the plans that states will be obtained and that the vehicle fluids shall be contained or
either (1) there are no floor drains, design meets that agency's drained from the vehicle immediately.
or (2) floor drains are connected to requirements. No person shall leave unattended drip wastewater pretreatment systems □ parts or other open containers prior to discharge to the sanitary containing vehicle fluid, unless such sewer and an industrial waste containers are in use or in an area of discharge permit will be obtained. secondary containment.
Refer to "Automotive Maintenance & Car
Care Best Management Practices for Auto
Body Shops, Auto Repair Shops, Car
Dealerships, Gas Stations and Fleet
Service Operations". Brochure can be
found at htt12: /_ /_rcflood.org/_ stormwater /_
Refer to Outdoor Cleaning Activities and
Professional Mobile Service Providers for
many of the Potential Sources of
Runoff Pollutants categories below.
Brochure can be found at
htt12: !. /_rcflood.org/_stormwater !.
STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST
IF THESE SOURCES WILL BE ... THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE ON THE PROJECT SITE ...
□
1 2 3 4
Potential Sources of Permanent Controls-Show on Permanent Controls-List in WQMP Operational BMPs-lnclude in WQMP
Runoff Pollutants WQMP Drawings Table and Narrative Table and Narrative
L. Fuel Dispensing □ Fueling areas6 shall have □ The property owner shall dry sweep
Areas impermeable floors (i.e., portland the fueling area routinely.
cement concrete or equivalent □ See the Fact Sheet SD-30 , "Fueling smooth impervious surface) that Areas" in the CASQA Stormwater are: a) graded at the minimum Quality Handbooks at slope necessary to prevent ponding; www.cabmphandbooks.com and b) separated from the rest of
the site by a grade break that
prevents run-on of stormwater to
the maximum extent practicable.
□ Fueling areas shall be covered by a
canopy that extends a minimum of
ten feet in each direction from each
pump. [Alternative: The fueling
area must be covered and the
cover's minimum dimensions must
be equal to or greater than the area
within the grade break or fuel
dispensing area1.] The canopy [or
cover] shall not drain onto the
fueling area.
6 The fueling area shall be defined as the area extending a minimum of 6.5 feet from the corner of each fuel dispenser or the length at which the hose and nozzle assembly may be operated plus
a minimum of one foot, whichever is greater.
STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST
IF THESE SOURCES WILL BE ... THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE ON THE PROJECT SITE ...
1 2 3 4
Potential Sources of Permanent Controls-Show on Permanent Controls-List in WQMP Operational BMPs-lnclude in WQMP
Runoff Pollutants WQMP Drawings Table and Narrative Table and Narrative
□ M. Loading Docks □ Show a preliminary design for the □ Move loaded and unloaded items
loading dock area, including indoors as soon as possible.
roofing and drainage. Loading □ See Fact Sheet SC-30, "Outdoor docks shall be covered and/ or Loading and Unloading," in the graded to minimize run-on to and CASQA Stormwater Quality runoff from the loading area. Roof Handbooks at downspouts shall be positioned to www.cabmphandbooks.com direct stormwater away from the
loading area. Water from loading
dock areas shall be drained to the
sanitary sewer, or diverted and
collected for ultimate discharge to
the sanitary sewer.
□ Loading dock areas draining
directly to the sanitary sewer shall
be equipped with a spill control
valve or equivalent device, which
shall be kept closed during periods
of operation.
□ Provide a roof overhang over the
loading area or install door skirts
( cowling) at each bay that enclose
the end of the trailer.
STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST
IF THESE SOURCES WILL BE ... THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE ON THE PROJECT SITE ...
1 2 3 4
Potential Sources of Permanent Controls-Show on Permanent Controls-List in WQMP Operational BMPs-lnclude in WQMP
Runoff Pollutants WQMP Drawings Table and Narrative Table and Narrative
0 N. Fire Sprinkler Test 0 Provide a means to drain fire 0 See the note in Fact Sheet SC-41,
Water sprinkler test water to the sanitary "Building and Grounds Maintenance,"
sewer. in the CASQA Stormwater Quality
Handbooks at
www.cabm12handbooks.com
O. Miscellaneous Drain 0 Boiler drain lines shall be directly
or Wash Water or Other or indirectly connected to the
Sources sanitary sewer system and may not
0 Boiler drain lines discharge to the storm drain
0 system. 0 Condensate drain lines Condensate drain lines may 0 Rooftop equipment discharge to landscaped areas if the
0 Drainage sumps flow is small enough that runoff
0 will not occur. Condensate drain
Roofing, gutters, and 0 lines may not discharge to the trim. storm drain system.
□ Other sources Rooftop equipment with potential
to produce pollutants shall be
0 roofed and/ or have secondary
containment.
Any drainage sumps on-site shall
0 feature a sediment sump to reduce
the quantity of sediment in
pumped water.
0 Avoid roofing, gutters, and trim
made of copper or other
unprotected metals that may leach
into runoff.
Include controls for other sources
as specified by local reviewer.
STORMWATER POLLUTANT SOURCES/SOURCE CONTROL CHECKLIST
IF THESE SOURCES WILL BE ... THEN YOUR WQMP SHOULD INCLUDE THESE SOURCE CONTROL BMPs, AS APPLICABLE ON THE PROJECT SITE ...
1 2 3 4
Potential Sources of Permanent Controls-Show on Permanent Controls-List in WQMP Operational BMPs-lnclude in WQMP
Runoff Pollutants WQMP Drawings Table and Narrative Table and Narrative
0 P. Plazas, sidewalks, 0 Sweep plazas, sidewalks, and parking
and parking lots. lots regularly to prevent accumulation
of litter and debris. Collect debris from
pressure washing to prevent entry into
the storm drain system. Collect
washwater containing any cleaning
agent or degreaser and discharge to
the sanitary sewer not to a storm drain.
ATTACHMENT 2
BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES
[NOT APPLICABLE.]
Indicate which Items are Included behind this cover sheet:
Attachment Contents Checklist
Sequence
Attachment 2a Hydromodification Management □ Included (N/A)
Exhibit (Required)
See Hydromodification Management
Exhibit Checklist on the back of this
Attachment cover sheet.
Attachment 2b Management of Critical Coarse □ Exhibit showing project drainage
Sediment Yield Areas (WMAA Exhibit boundaries marked on WMAA
is required, additional analyses are Critical Coarse Sediment Yield
optional) Area Map (Required)
See Section 6.2 of the BMP Design Optional analyses for Critical Coarse
Manual. 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 lg] Not performed
Channels (Optional) □ Included
See Section 6.3.4 of the BMP Design
Manual.
Attachment 2d Flow Control Facility Design and □ Included
Structural BMP Drawdown N/A
Calculations (Required)
See Chapter 6 and Appendix G of the
BMP Design Manual
ATTACHMENT 2
BACKUP FOR
HYDROMODIFICATION CONTROL
MEASURES
This Attachment 2 is not applicable to this site since it is HMP
Exempt beacuse: 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.
This project discharges directly to Agua Hedionda Lagoon.
Please refer to Hydromodification Exemption Analysis for
Select Carlsbad Watersheds, prepared by Chang Consul-
tants, dated September 17, 2015.
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
FT-4
Dry Extended Detention Basin
BMP MAINTENANCE FACT SHEET
FOR
FLOW-THRU STRUCTURAL BMP FT-4 DRY EXTENDED DETENTION BASIN
Dry extended detention basins are basins that have been designed to detain storm water for an extended period
to allow sedimentation and typically drain completely between storm events. The slopes, bottom, and forebay of
above-ground dry extended detention basins are typically vegetated. Dry extended detention basins may serve
multiple uses including parks, playing fields, tennis courts, open space, and overflow parking lots. This BMP
category also includes detention basins that serve a purpose of flow control for hydromodification management
only, which may or may not include vegetation. They can be underground structures, in many possible
configurations, including both proprietary and non-proprietary systems. They may be constructed of a single large
vault, one or multiple large pipes, or other modular units. Outlet structures control outflow from either above-
ground or underground detention systems; outlet structures may be weirs, orifice plates, risers, or other control
structures. Typical dry extended detention basin components include:
• Forebay for pretreatment
• Surface ponding for captured flows
• Vegetation selected based on basin use, climate and ponding depth (above-ground basins)
• Low flow channel, outlet, and overflow device
• Impermeable liner or uncompacted native soils at the bottom of the facility
Normal Expected Maintenance
Dry extended detention basins require routine maintenance to: remove accumulated materials such as sediment,
trash or debris; maintain vegetation health; and maintain integrity of side slopes, 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 or underground ponding
longer than approximately 96 hours following a storm event poses a risk of vector (mosquito) breeding.
Poor drainage can result from clogging of underlying native soils and/or the outlet structure. The specific
cause of the drainage issue must be determined and corrected. If it is determined that the drainage of the
basin relies on infiltration and the underlying native soils have been compacted or do not have the
infiltration capacity expected, the [City Engineer] shall be contacted prior to any additional repairs or
reconstruction.
• 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.
• 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.
FT-4 Page 1 of 12
January 12, 2017
FT-4
Dry Extended Detention Basin
Other Special Considerations
Some above-ground dry extended detention basins are vegetated structural BMPs. 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.
Underground dry extended detention basins are typically designed to be cleaned from above-ground using a
vactor. If maintenance conditions require maintenance personnel to enter the underground structure, the
maintenance personnel must be trained and certified in confined space entry.
FT-4 Page 2 of 12
January 12, 2017
FT-4
Dry Extended Detention Basin
SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR FT-4 DRY EXTENDED DETENTION BASIN
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
Accumulation of sediment, litter, or debris in forebay
and/or basin
Remove and properly dispose of accumulated materials,
(without damage to vegetation when applicable).
• Inspect monthly. If the forebay is 25% full* or more in
one month, increase inspection frequency to monthly
plus after every 0.1-inch or larger storm event.
• Remove any accumulated materials found within the
basin area at each inspection.
• When the BMP includes a forebay, materials must be
removed from the forebay when the forebay is 25%
full*, or if accumulation within the forebay blocks flow
to the basin.
Obstructed inlet or outlet structure Clear blockage. • Inspect monthly and after every 0.5-inch or larger
storm event.
• Remove any accumulated materials found at each
inspection.
Poor vegetation establishment (when the BMP includes
vegetated surface by design)
Re-seed, re-plant, or re-establish vegetation per original
plans.
• Inspect monthly.
• Maintenance when needed.
Dead or diseased vegetation (when the BMP includes
vegetated surface by design)
Remove dead or diseased vegetation, re-seed, re-plant,
or re-establish vegetation per original plans.
• Inspect monthly.
• Maintenance when needed.
Overgrown vegetation (when the BMP includes
vegetated surface by design)
Mow or trim as appropriate. • Inspect monthly.
• Maintenance when needed.
*“25% full” is defined as ¼ of the depth from the design bottom elevation to the crest of the outflow structure (e.g., if the height to the outflow opening is 12 inches from the
bottom elevation, then the materials must be removed when there is 3 inches of accumulation – this should be marked on the outflow structure).
FT-4 Page 3 of 12
January 12, 2017
FT-4
Dry Extended Detention Basin
SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR FT-4 DRY EXTENDED DETENTION BASIN (Continued from previous page)
Threshold/Indicator Maintenance Action Typical Maintenance Frequency
Erosion due to concentrated irrigation flow Repair/re-seed/re-plant eroded areas and adjust the
irrigation system.
• Inspect monthly.
• Maintenance when needed.
Erosion due to concentrated storm water runoff flow Repair/re-seed/re-plant eroded areas, and make
appropriate corrective measures such as 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.
• Inspect after every 0.5-inch or larger storm event. If
erosion due to storm water flow has been observed,
increase inspection frequency to after every 0.1-inch
or larger storm event.
• Maintenance when needed. 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.
Standing water in above-ground BMP for longer than 24-
96 hours following a storm event
Make appropriate corrective measures such as adjusting
irrigation system, removing obstructions of debris or
invasive vegetation, or removing/replacing clogged or
compacted surface treatments and/or scarifying or
tilling native soils. Always remove deposited sediments
before scarification, and use a hand-guided rotary tiller.
If it is determined that the drainage of the basin relies
on infiltration and the underlying native soils have been
compacted or do not have the infiltration capacity
expected, the [City Engineer] shall be contacted prior to
any additional repairs or reconstruction.
• 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.
Standing water in underground BMP for longer than 24-
96 hours following a storm event
Make appropriate corrective measures such as removing
obstructions at the outlet, clearing underdrains, or
flushing fine sediment from aggregate layer when
applicable. If it is determined that the drainage of the
basin relies on infiltration and the underlying native soils
have been compacted or do not have the infiltration
capacity expected, the [City Engineer] shall be contacted
prior to any additional repairs or reconstruction.
• 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.
FT-4 Page 4 of 12
January 12, 2017
FT-4
Dry Extended Detention Basin
SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR FT-4 DRY EXTENDED DETENTION BASIN (Continued from previous page)
Threshold/Indicator Maintenance Action Typical Maintenance Frequency
Presence of mosquitos/larvae
For images of egg rafts, larva, pupa, and adult
mosquitos, see
http://www.mosquito.org/biology
If mosquitos/larvae are observed: first, immediately
remove and properly dispose any standing water;
second, make corrective measures as applicable to
restore BMP drainage to prevent standing water. For
underground detention basins, ensure access covers are
tight fitting, with gaps or holes no greater than 1/16
inch, and/or install barriers such as inserts or screens
that prevent mosquito access to the subsurface storage.
If mosquitos persist following corrective measures to
remove standing water, or if the BMP design does not
meet the 96-hour drawdown criteria due to release
rates controlled by an orifice installed on the
underdrain, the [City Engineer] shall be contacted to
determine a solution. A different BMP type, or a Vector
Management Plan prepared with concurrence from the
County of San Diego Department of Environmental
Health, may be required.
• 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
Damage to structural components such as weirs, inlet or
outlet structures
Repair or replace as applicable. • Inspect annually.
• Maintenance when needed.
References
American Mosquito Control Association.
http://www.mosquito.org/
California Storm Water Quality Association (CASQA). 2003. Municipal BMP Handbook.
https://www.casqa.org/resources/bmp-handbooks/municipal-bmp-handbook
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 FT-4.
http://www.projectcleanwater.org/index.php?option=com_content&view=article&id=250&Itemid=220
FT-4 Page 5 of 12
January 12, 2017
FT-4
Dry Extended Detention Basin
Page Intentionally Blank for Double-Sided Printing
FT-4 Page 6 of 12
January 12, 2017
FT-4
Dry Extended Detention Basin
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 FT-4 DRY EXTENDED DETENTION BASIN PAGE 1 of 5
Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted
Accumulation of sediment, litter, or debris
Materials must be removed from the forebay
when the forebay is 25% full*. In any case,
materials must be removed if accumulation
blocks flow to the basin area.
Materials must be removed from the basin area
any time accumulation is observed in the basin
area.
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Remove and properly dispose of
accumulated materials, (without
damage to the vegetation when
applicable)
☐ If accumulation within the forebay is
greater than 25% in one month,
increase the inspection and
maintenance frequency*
☐ Other / Comments:
*“25% full” is defined as ¼ of the depth from the design bottom elevation to the crest of the outflow structure (e.g., if the height to the outflow opening is 12 inches from the
bottom elevation, then the materials must be removed when there is 3 inches of accumulation – this should be marked on the outflow structure).
**If no forebay is present, if sediment, litter, or debris accumulation exceeds 25% of the surface ponding volume within one month, add a forebay or other pre-treatment
measures within the tributary area draining to the BMP to intercept the materials.
FT-4 Page 7 of 12
January 12, 2017
I I
I
FT-4
Dry Extended Detention Basin
Date: Inspector: BMP ID No.:
Permit No.: APN(s):
INSPECTION AND MAINTENANCE CHECKLIST FOR FT-4 DRY EXTENDED DETENTION BASIN PAGE 2 of 5
Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted
Poor vegetation establishment
(when the BMP includes vegetated surface by
design)
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Re-seed, re-plant, or re-establish
vegetation per original plans
☐ Other / Comments:
Dead or diseased vegetation
(when the BMP includes vegetated surface by
design)
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Remove dead or diseased vegetation,
re-seed, re-plant, or re-establish
vegetation per original plans
☐ Other / Comments:
Overgrown vegetation
(when the BMP includes vegetated surface by
design)
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Mow or trim as appropriate
☐ Other / Comments:
FT-4 Page 8 of 12
January 12, 2017
FT-4
Dry Extended Detention Basin
Date: Inspector: BMP ID No.:
Permit No.: APN(s):
INSPECTION AND MAINTENANCE CHECKLIST FOR FT-4 DRY EXTENDED DETENTION BASIN PAGE 3 of 5
Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted
Erosion due to concentrated irrigation flow
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Repair/re-seed/re-plant eroded areas
and adjust the irrigation system
☐ Other / Comments:
Erosion due to concentrated storm water runoff
flow
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Repair/re-seed/re-plant eroded areas,
and make appropriate corrective
measures such as 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 / Comments:
FT-4 Page 9 of 12
January 12, 2017
FT-4
Dry Extended Detention Basin
Date: Inspector: BMP ID No.:
Permit No.: APN(s):
INSPECTION AND MAINTENANCE CHECKLIST FOR FT-4 DRY EXTENDED DETENTION BASIN PAGE 4 of 5
Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted
Obstructed inlet or outlet structure
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Clear blockage
☐ Other / Comments:
Damage to structural components such as weirs,
inlet or outlet structures
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Repair or replace as applicable
☐ Other / Comments:
FT-4 Page 10 of 12
January 12, 2017
FT-4
Dry Extended Detention Basin
Date: Inspector: BMP ID No.:
Permit No.: APN(s):
INSPECTION AND MAINTENANCE CHECKLIST FOR FT-4 DRY EXTENDED DETENTION BASIN PAGE 5 of 5
Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted
Standing water in above-ground BMP for longer
than 24-96 hours following a storm event*
☐ Make appropriate corrective measures
such as adjusting irrigation system,
removing obstructions of debris or
invasive vegetation, or
repairing/replacing clogged or
compacted soils.*
☐ Other / Comments:
Standing water in underground BMP for longer
than 24-96 hours following a storm event*
☐ Make appropriate corrective measures
such as removing debris obstructions,
clearing underdrains, or flushing fine
sediment from aggregate layer when
applicable.*
☐ Other / Comments:
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
☐ Apply corrective measures to remove
standing water in BMP when standing
water occurs for longer than 24-96
hours following a storm event.**
☐ Other / Comments:
FT-4 Page 11 of 12
January 12, 2017
FT-4
Dry Extended Detention Basin
*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 outlet structure or the underlying soils. The specific cause of
the drainage issue must be determined and corrected. If it is determined that the drainage of the basin relies on infiltration and the underlying native soils have been compacted
or do not have the infiltration capacity expected, the [City Engineer] shall be contacted prior to any additional repairs or reconstruction.
**If mosquitos persist following corrective measures to remove standing water, or if the BMP design does not meet the 96-hour drawdown criteria due to release rates
controlled by an orifice installed on the underdrain, the [City Engineer] shall be contacted to determine a solution. A different BMP type, or a Vector Management Plan prepared
with concurrence from the County of San Diego Department of Environmental Health, may be required.
FT-4 Page 12 of 12
January 12, 2017
Site Design & Landscape Planning SD-10
Description
Design Objectives
0 Maximize Infiltration
0 Provide Retention
0 Slow Runoff
0 Minimize Impervious Land
Coverage
Prohibit Dumping of Improper
Materials
Contain Pollutants
Collect and Convey
Each project site possesses unique topographic, hydrologic, and vegetative features, some of
which are more suitable for development than others. Integrating and incorporating
appropriate landscape planning methodologies into the project design is the most effective
action that can be done to minimize surface and groundwater contamination from stormwater.
Approach
Landscape planning should couple consideration of land suitability for urban uses with
consideration of community goals and projected growth. Project plan designs should conserve
natural areas to the extent possible, maximize natural water storage and infiltration
opportunities, and protect slopes and channels.
Suitable Applications
Appropriate applications include residential, commercial and industrial areas planned for
development or redevelopment.
Design Considerations
Design requirements for site design and landscapes planning
should conform to applicable standards and specifications of
agencies with jurisdiction and be consistent with applicable
General Plan and Local Area Plan policies.
January 2003 California Stormwater BMP Handbook
New Development and Redevelopment
www.cabmphandbooks.com
CALIFORl\1A SfORMWATER
I I<
1 of 4
SD-10 Site Design & Landscape Planning
Designing New Installations
Begin the development of a plan for the landscape unit with attention to the following general
principles:
■ Formulate the plan on the basis of clearly articulated community goals. Carefully identify
conflicts and choices between retaining and protecting desired resources and community
growth.
■ Map and assess land suitability for urban uses. Include the following landscape features in
the assessment: wooded land, open unwooded land, steep slopes, erosion-prone soils,
foundation suitability, soil suitability for waste disposal, aquifers, aquifer recharge areas,
wetlands, floodplains, surface waters, agricultural lands, and various categories of urban
land use. When appropriate, the assessment can highlight outstanding local or regional
resources that the community determines should be protected (e.g., a scenic area,
recreational area, threatened species habitat, farmland, fish run). Mapping and assessment
should recognize not only these resources but also additional areas needed for their
sustenance.
Project plan designs should conserve natural areas to the extent possible, maximize natural
water storage and infiltration opportunities, and protect slopes and channels.
Conserve Natural Areas during Landscape Planning
If applicable, the following items are required and must be implemented in the site layout
during the subdivision design and approval process, consistent with applicable General Plan and
Local Area Plan policies:
■ Cluster development on least-sensitive portions of a site while leaving the remaining land in
a natural undisturbed condition.
■ Limit clearing and grading of native vegetation at a site to the minimum amount needed to
build lots, allow access, and provide fire protection.
■ Maximize trees and other vegetation at each site by planting additional vegetation, clustering
tree areas, and promoting the use of native and/ or drought tolerant plants.
■ Promote natural vegetation by using parking lot islands and other landscaped areas.
■ Preserve riparian areas and wetlands.
Maximize Natural Water Storage and Infiltration Opportunities Within the Landscape Unit
■ Promote the conservation of forest cover. Building on land that is already deforested affects
basin hydrology to a lesser extent than converting forested land. Loss of forest cover reduces
interception storage, detention in the organic forest floor layer, and water losses by
evapotranspiration, resulting in large peak runoff increases and either their negative effects
or the expense of countering them with structural solutions.
■ Maintain natural storage reservoirs and drainage corridors, including depressions, areas of
permeable soils, swales, and intermittent streams. Develop and implement policies and
2 of 4 California Stormwater BMP Handbook
New Development and Redevelopment
www.cabmphandbooks.com
January 2003
Site Design & Landscape Planning SD-10
regulations to discourage the clearing, filling, and channelization of these features. Utilize
them in drainage networks in preference to pipes, culverts, and engineered ditches.
■ Evaluating infiltration opportunities by referring to the stormwater management manual for
the jurisdiction and pay particular attention to the selection criteria for avoiding
groundwater contamination, poor soils, and hydrogeological conditions that cause these
facilities to fail. If necessary, locate developments with large amounts of impervious
surfaces or a potential to produce relatively contaminated runoff away from groundwater
recharge areas.
Protection of Slopes and Channels during Landscape Design
■ Convey runoff safely from the tops of slopes.
■ Avoid disturbing steep or unstable slopes.
■ Avoid disturbing natural channels.
■ Stabilize disturbed slopes as quickly as possible.
■ Vegetate slopes with native or drought tolerant vegetation.
■ Control and treat flows in landscaping and/ or other controls prior to reaching existing
natural drainage systems.
■ Stabilize temporary and permanent channel crossings as quickly as possible, and ensure that
increases in run-off velocity and frequency caused by the project do not erode the channel.
■ Install energy dissipaters, such as riprap, at the outlets of new storm drains, culverts,
conduits, or channels that enter unlined channels in accordance with applicable
specifications to minimize erosion. Energy dissipaters shall be installed in such a way as to
minimize impacts to receiving waters.
■ Line on-site conveyance channels where appropriate, to reduce erosion caused by increased
flow velocity due to increases in tributary impervious area. The first choice for linings
should be grass or some other vegetative surface, since these materials not only reduce
runoff velocities, but also provide water quality benefits from filtration and infiltration. If
velocities in the channel are high enough to erode grass or other vegetative linings, riprap,
concrete, soil cement, or geo-grid stabilization are other alternatives.
■ Consider other design principles that are comparable and equally effective.
Redeveloping Existing Installations
Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.)
define "redevelopment" in terms of amounts of additional impervious area, increases in gross
floor area and/ or exterior construction, and land disturbing activities with structural or
impervious surfaces. The definition of" redevelopment" must be consulted to determine
whether or not the requirements for new development apply to areas intended for
redevelopment. If the definition applies, the steps outlined under "designing new installations"
above should be followed.
January 2003 California Stormwater BMP Handbook
New Development and Redevelopment
www.cabmphandbooks.com
3 of 4
SD-10 Site Design & Landscape Planning
Redevelopment may present significant opportunity to add features which had not previously
been implemented. Examples include incorporation of depressions, areas of permeable soils,
and swales in newly redeveloped areas. While some site constraints may exist due to the status
of already existing infrastructure, opportunities should not be missed to maximize infiltration,
slow runoff, reduce impervious areas, disconnect directly connected impervious areas.
Other Resources
A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County
Department of Public Works, May 2002.
Stormwater Management Manual for Western Washington, Washington State Department of
Ecology, August 2001.
Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of
San Diego, and Cities in San Diego County, February 14, 2002.
Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood
Control District, and the Incorporated Cities of Orange County, Draft February 2003.
Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures,
July 2002.
4 of 4 California Stormwater BMP Handbook
New Development and Redevelopment
www.cabmphandbooks.com
January 2003
Roof Runoff Controls
Rain Garden
Description
Various roof runoff controls are available to address stormwater
SD-11
Design Objectives
0 Maximize Infiltration
0 Provide Retention
0 Slow Runoff
Minimize Impervious Land
Coverage
Prohibit Dumping of Improper
Materials
0 Contain Pollutants
Collect and Convey
that drains off rooftops. The objective is to reduce the total volume and rate of runoff from
individual lots, and retain the pollutants on site that may be picked up from roofing materials
and atmospheric deposition. Roof runoff controls consist of directing the roof runoff away from
paved areas and mitigating flow to the storm drain system through one of several general
approaches: cisterns or rain barrels; dry wells or infiltration trenches; pop-up emitters, and
foundation planting. The first three approaches require the roof runoff to be contained in a
gutter and downspout system. Foundation planting provides a vegetated strip under the drip
line of the roof.
Approach
Design of individual lots for single-family homes as well as lots for higher density residential and
commercial structures should consider site design provisions for containing and infiltrating roof
runoff or directing roof runoff to vegetative swales or buffer areas. Retained water can be reused
for watering gardens, lawns, and trees. Benefits to the environment include reduced demand for
potable water used for irrigation, improved stormwater quality, increased groundwater
recharge, decreased runoff volume and peak flows, and decreased flooding potential.
Suitable Applications
Appropriate applications include residential, commercial and industrial areas planned for
development or redevelopment.
Design Considerations
Designing New Installations
Cisterns or Rain Barrels
One method of addressing roof runoff is to direct roof downspouts
to cisterns or rain barrels. A cistern is an above ground storage
vessel with either a manually operated valve or a permanently
open outlet. Roof runoff is temporarily stored and then released
for irrigation or infiltration between storms. The number of rain
CALIFORl\1A SfORMWATER
January 2003 California Stormwater BMP Handbook
New Development and Redevelopment
www.cabmphandbook.com
I I<
1 of 3
SD-11 Roof Runoff Controls
barrels needed is a function of the rooftop area. Some low impact developers recommend that
every house have at least 2 rain barrels, with a minimum storage capacity of 1000 liters. Roof
barrels serve several purposes including mitigating the first flush from the roof which has a high
volume, amount of contaminants, and thermal load. Several types of rain barrels are
commercially available. Consideration must be given to selecting rain barrels that are vector
proof and childproof. In addition, some barrels are designed with a bypass valve that filters out
grit and other contaminants and routes overflow to a soak-away pit or rain garden.
If the cistern has an operable valve, the valve can be closed to store stormwater for irrigation or
infiltration between storms. This system requires continual monitoring by the resident or
grounds crews, but provides greater flexibility in water storage and metering. If a cistern is
provided with an operable valve and water is stored inside for long periods, the cistern must be
covered to prevent mosquitoes from breeding.
A cistern system with a permanently open outlet can also provide for metering stormwater
runoff. If the cistern outlet is significantly smaller than the size of the downspout inlet (say ¼ to
½ inch diameter), runoff will build up inside the cistern during storms, and will empty out
slowly after peak intensities subside. This is a feasible way to mitigate the peak flow increases
caused by rooftop impervious land coverage, especially for the frequent, small storms.
Dry wells and Infiltration Trenches
Roof downspouts can be directed to dry wells or infiltration trenches. A dry well is constructed
by excavating a hole in the ground and filling it with an open graded aggregate, and allowing the
water to fill the dry well and infiltrate after the storm event. An underground connection from
the downspout conveys water into the dry well, allowing it to be stored in the voids. To
minimize sedimentation from lateral soil movement, the sides and top of the stone storage
matrix can be wrapped in a permeable filter fabric, though the bottom may remain open. A
perforated observation pipe can be inserted vertically into the dry well to allow for inspection
and maintenance.
In practice, dry wells receiving runoff from single roof downspouts have been successful over
long periods because they contain very little sediment. They must be sized according to the
amount of rooftop runoff received, but are typically 4 to 5 feet square, and 2 to 3 feet deep, with
a minimum of 1-foot soil cover over the top (maximum depth of 10 feet).
To protect the foundation, dry wells must be set away from the building at least 10 feet. They
must be installed in solids that accommodate infiltration. In poorly drained soils, dry wells have
very limited feasibility.
Infiltration trenches function in a similar manner and would be particularly effective for larger
roof areas. An infiltration trench is a long, narrow, rock-filled trench with no outlet that receives
stormwater runoff. These are described under Treatment Controls.
Pop-up Drainage Emitter
Roof downspouts can be directed to an underground pipe that daylights some distance from the
building foundation, releasing the roof runoff through a pop-up emitter. Similar to a pop-up
irrigation head, the emitter only opens when there is flow from the roof. The emitter remains
flush to the ground during dry periods, for ease of lawn or landscape maintenance.
2 of 3 California Stormwater BMP Handbook
New Development and Redevelopment
www.cabmphandbook.com
January 2003
Roof Runoff Controls SD-11
Foundation Planting
Landscape planting can be provided around the base to allow increased opportunities for
stormwater infiltration and protect the soil from erosion caused by concentrated sheet flow
coming off the roof. Foundation plantings can reduce the physical impact of water on the soil
and provide a subsurface matrix of roots that encourage infiltration. These plantings must be
sturdy enough to tolerate the heavy runoff sheet flows, and periodic soil saturation.
Redeveloping Existing Installations
Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.)
define "redevelopment" in terms of amounts of additional impervious area, increases in gross
floor area and/ or exterior construction, and land disturbing activities with structural or
impervious surfaces. The definition of" redevelopment" must be consulted to determine
whether or not the requirements for new development apply to areas intended for
redevelopment. If the definition applies, the steps outlined under "designing new installations"
above should be followed.
Supplemental Information
Examples
■ City of Ottawa's Water Links Surface -Water Quality Protection Program
■ City of Toronto Downspout Disconnection Program
■ City of Boston, MA, Rain Barrel Demonstration Program
Other Resources
Hager, Marty Catherine, Stormwater, "Low-Impact Development", January/February 2003.
www.stormh2o.com
Low Impact Urban Design Tools, Low Impact Development Design Center, Beltsville, MD.
www.lid-stormwater.net
Start at the Source, Bay Area Stormwater Management Agencies Association, 1999 Edition
January 2003 California Stormwater BMP Handbook
New Development and Redevelopment
www.cabmphandbook.com
3 of 3
Efficient Irrigation SD-12
Design Objectives
0 Maximize Infiltration
0 Provide Retention
0 Slow Runoff
Minimize Impervious Land
Coverage
Prohibit Dumping of Improper
Materials
Description
Contain Pollutants
Collect and Convey
Irrigation water provided to landscaped areas may result in excess irrigation water being
conveyed into stormwater drainage systems.
Approach
Project plan designs for development and redevelopment should include application methods of
irrigation water that minimize runoff of excess irrigation water into the stormwater conveyance
system.
Suitable Applications
Appropriate applications include residential, commercial and industrial areas planned for
development or redevelopment. (Detached residential single-family homes are typically
excluded from this requirement.)
Design Considerations
Designing New Installations
The following methods to reduce excessive irrigation runoff should be considered, and
incorporated and implemented where determined applicable and feasible by the Permittee:
■ Employ rain-triggered shutoff devices to prevent irrigation after precipitation.
■ Design irrigation systems to each landscape area's specific water requirements.
■ Include design featuring flow reducers or shutoff valves
triggered by a pressure drop to control water loss in the event
of broken sprinkler heads or lines.
■ Implement landscape plans consistent with County or City
water conservation resolutions, which may include provision
of water sensors, programmable irrigation times (for short
cycles), etc.
CALIFORl\1A SfORMWATER
January 2003 California Stormwater BMP Handbook
New Development and Redevelopment
www.cabmphandbooks.com
I I<
1 of 2
SD-12 Efficient Irrigation
■ Design timing and application methods of irrigation water to minimize the runoff of excess
irrigation water into the storm water drainage system.
■ Group plants with similar water requirements in order to reduce excess irrigation runoff and
promote surface filtration. Choose plants with low irrigation requirements (for example,
native or drought tolerant species). Consider design features such as:
Using mulches (such as wood chips or bar) in planter areas without ground cover to
minimize sediment in runoff
Installing appropriate plant materials for the location, in accordance with amount of
sunlight and climate, and use native plant materials where possible and/ or as
recommended by the landscape architect
Leaving a vegetative barrier along the property boundary and interior watercourses, to
act as a pollutant filter, where appropriate and feasible
Choosing plants that minimize or eliminate the use of fertilizer or pesticides to sustain
growth
■ Employ other comparable, equally effective methods to reduce irrigation water runoff.
Redeveloping Existing Installations
Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.)
define "redevelopment" in terms of amounts of additional impervious area, increases in gross
floor area and/ or exterior construction, and land disturbing activities with structural or
impervious surfaces. The definition of" redevelopment" must be consulted to determine
whether or not the requirements for new development apply to areas intended for
redevelopment. If the definition applies, the steps outlined under "designing new installations"
above should be followed.
Other Resources
A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County
Department of Public Works, May 2002.
Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of
San Diego, and Cities in San Diego County, February 14, 2002.
Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood
Control District, and the Incorporated Cities of Orange County, Draft February 2003.
Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures,
July 2002.
2 of 2 California Stormwater BMP Handbook
New Development and Redevelopment
www.cabmphandbooks.com
January 2003
Storm Drain Signage
Description
SD-13
Design Objectives
Maximize Infiltration
Provide Retention
Slow Runoff
Minimize Impervious Land
Coverage
0 Prohibit Dumping of Improper
Materials
Contain Pollutants
Collect and Convey
Waste materials dumped into storm drain inlets can have severe impacts on receiving and
ground waters. Posting notices regarding discharge prohibitions at storm drain inlets can
prevent waste dumping. Storm drain signs and stencils are highly visible source controls that
are typically placed directly adjacent to storm drain inlets.
Approach
The stencil or affixed sign contains a brief statement that prohibits dumping of improper
materials into the urban runoff conveyance system. Storm drain messages have become a
popular method of alerting the public about the effects of and the prohibitions against waste
disposal.
Suitable Applications
Stencils and signs alert the public to the destination of pollutants discharged to the storm drain.
Signs are appropriate in residential, commercial, and industrial areas, as well as any other area
where contributions or dumping to storm drains is likely.
Design Considerations
Storm drain message markers or placards are recommended at all storm drain inlets within the
boundary of a development project. The marker should be placed in clear sight facing toward
anyone approaching the inlet from either side. All storm drain inlet locations should be
identified on the development site map.
Designing New Installations
The following methods should be considered for inclusion in the
project design and show on project plans:
■ Provide stenciling or labeling of all storm drain inlets and
catch basins, constructed or modified, within the project area
with prohibitive language. Examples include "NO DUMPING
January 2003 California Stormwater BMP Handbook
New Development and Redevelopment
www.cabmphandbooks.com
CALIFORl\1A SfORMWATER
I I<
1 of 2
SD-13 Storm Drain Signage
-DRAINS TO OCEAN" and/or other graphical icons to discourage illegal dumping.
■ Post signs with prohibitive language and/ or graphical icons, which prohibit illegal dumping
at public access points along channels and creeks within the project area.
Note -Some local agencies have approved specific signage and/or storm drain message placards
for use. Consult local agency stormwater staff to determine specific requirements for placard
types and methods of application.
Redeveloping Existing Installations
Various jurisdictional stormwater management and mitigation plans (SUSMP, WQMP, etc.)
define "redevelopment" in terms of amounts of additional impervious area, increases in gross
floor area and/ or exterior construction, and land disturbing activities with structural or
impervious surfaces. If the project meets the definition of "redevelopment", then the
requirements stated under " designing new installations" above should be included in all project
design plans.
Additional Information
Maintenance Considerations
■ Legibility of markers and signs should be maintained. If required by the agency with
jurisdiction over the project, the owner/operator or homeowner's association should enter
into a maintenance agreement with the agency or record a deed restriction upon the
property title to maintain the legibility of placards or signs.
Placement
■ Signage on top of curbs tends to weather and fade.
■ Signage on face of curbs tends to be worn by contact with vehicle tires and sweeper brooms.
Supplemental Information
Examples
■ Most MS4 programs have storm drain signage programs. Some MS4 programs will provide
stencils, or arrange for volunteers to stencil storm drains as part of their outreach program.
Other Resources
A Manual for the Standard Urban Stormwater Mitigation Plan (SUSMP), Los Angeles County
Department of Public Works, May 2002.
Model Standard Urban Storm Water Mitigation Plan (SUSMP) for San Diego County, Port of
San Diego, and Cities in San Diego County, February 14, 2002.
Model Water Quality Management Plan (WQMP) for County of Orange, Orange County Flood
Control District, and the Incorporated Cities of Orange County, Draft February 2003.
Ventura Countywide Technical Guidance Manual for Stormwater Quality Control Measures,
July 2002.
2 of 2 California Stormwater BMP Handbook
New Development and Redevelopment
www.cabmphandbooks.com
January 2003
Non-Stormwater Discharges
JJrotect tire 1311 y
Description
Use the Household Waste
Treat111e11t Facility
Non-stormwater discharges are those flows that do not consist
entirely of stormwater. Some non-stormwater discharges do not
include pollutants and may be discharged to the storm drain.
These include uncontaminated groundwater and natural springs.
There are also some non-stormwater discharges that typically do
not contain pollutants and may be discharged to the storm drain
with conditions. These include car washing, air conditioner
condensate, etc. However there are certain non-stormwater
discharges that pose environmental concern. These discharges
may originate from illegal dumping or from internal floor drains,
appliances, industrial processes, sinks, and toilets that are
connected to the nearby storm drainage system. These
discharges ( which may include: process waste waters, cooling
waters, wash waters, and sanitary wastewater) can carry
substances such as paint, oil, fuel and other automotive fluids,
chemicals and other pollutants into storm drains. They can
generally be detected through a combination of detection and
elimination. The ultimate goal is to effectively eliminate non-
stormwater discharges to the stormwater drainage system
through implementation of measures to detect, correct, and
enforce against illicit connections and illegal discharges of
pollutants on streets and into the storm drain system and creeks.
Approach
Initially the industry must make an assessment of non-
stormwater discharges to determine which types must be
eliminated or addressed through BMPs. The focus of the
following approach is in the elimination of non-stormwater
discharges.
Jan uary 2003 California Stormwater BMP Handbook
Industrial and Commercial
www.cabmphandbooks.com
SC-10
Objectives
■ Cover
■ Contain
■ Educate
■ Reduce/Minimize
■ Product Substitution
Targeted Constituents
Sediment
Nutrients
Trash
Metals
Bacteria
Oil and Grease
Organics
Association
✓
✓
✓
✓
✓
1 of 6
SC-10 Non-Stormwater Discharges
Pollution Prevention
■ Ensure that used oil, used antifreeze, and hazardous chemical recycling programs are being
implemented. Encourage litter control.
Suggested Protocols
Recommended Complaint Investigation Equipment
■ Field Screening Analysis
pH paper or meter
Commercial stormwater pollutant screening kit that can detect for reactive phosphorus,
nitrate nitrogen, ammonium nitrogen, specific conductance, and turbidity
Sample jars
Sample collection pole
A tool to remove access hole covers
■ Laboratory Analysis
Sample cooler
Ice
Sample jars and labels
Chain of custody forms
■ Documentation
Camera
Notebook
Pens
Notice of Violation forms
Educational materials
General
■ Develop clear protocols and lines of communication for effectively prohibiting non-
stormwater discharges, especially those that are not classified as hazardous. These are often
not responded to as effectively as they need to be.
■ Stencil or demarcate storm drains, where applicable, to prevent illegal disposal of pollutants.
Storm drain inlets should have messages such as "Dump No Waste Drains to Stream"
stenciled or demarcated next to them to warn against ignorant or intentional dumping of
pollutants into the storm drainage system.
2 of 6 California Stormwater BMP Handbook
Industrial and Commercial
www.cabmphandbooks.com
January 2003
Non-Stormwater Discharges SC-10
■ See SC44 Stormwater Drainage System Maintenance for additional information.
Illicit Connections
■ Locate discharges from the industrial storm drainage system to the municipal storm drain
system through review of "as-built" piping schematics.
■ Isolate problem areas and plug illicit discharge points.
■ Locate and evaluate all discharges to the industrial storm drain system.
Visual Inspection and Inventory
■ Inventory and inspect each discharge point during dry weather.
■ Keep in mind that drainage from a storm event can continue for a day or two following the
end of a storm and groundwater may infiltrate the underground stormwater collection
system. Also, non-stormwater discharges are often intermittent and may require periodic
inspections.
Review Infield Piping
■ A review of the "as-built" piping schematic is a way to determine if there are any connections
to the stormwater collection system.
■ Inspect the path of floor drains in older buildings.
Smoke Testing
■ Smoke testing of wastewater and stormwater collection systems is used to detect
connections between the two systems.
■ During dry weather the stormwater collection system is filled with smoke and then traced to
sources. The appearance of smoke at the base of a toilet indicates that there may be a
connection between the sanitary and the stormwater system.
Dye Testing
■ A dye test can be performed by simply releasing a dye into either your sanitary or process
wastewater system and examining the discharge points from the stormwater collection
system for discoloration.
TV Inspection of Drainage System
■ TV Cameras can be employed to visually identify illicit connections to the industrial storm
drainage system.
Illegal Dumping
■ Regularly inspect and clean up hot spots and other storm drainage areas where illegal
dumping and disposal occurs.
■ On paved surfaces, clean up spills with as little water as possible. Use a rag for small spills, a
damp mop for general cleanup, and absorbent material for larger spills. If the spilled
material is hazardous, then the used cleanup materials are also hazardous and must be sent
to a certified laundry (rags) or disposed of as hazardous waste.
January 2003 California Stormwater BMP Handbook
Industrial and Commercial
www.cabmphandbooks.com
3 of 6
SC-10 Non-Stormwater Discharges
■ Never hose down or bury dry material spills. Sweep up the material and dispose of properly.
■ Use adsorbent materials on small spills rather than hosing down the spill. Remove the
adsorbent materials promptly and dispose of properly.
■ For larger spills, a private spill cleanup company or Hazmat team may be necessary.
Once a site has been cleaned:
■ Post "No Dumping" signs with a phone number for reporting dumping and disposal.
■ Landscaping and beautification efforts of hot spots may also discourage future dumping, as
well as provide open space and increase property values.
■ Lighting or barriers may also be needed to discourage future dumping.
■ See fact sheet SC11 Spill Prevention, Control, and Cleanup.
Inspection
■ Regularly inspect and clean up hot spots and other storm drainage areas where illegal
dumping and disposal occurs.
■ Conduct field investigations of the industrial storm drain system for potential sources of
non-stormwater discharges.
■ Pro-actively conduct investigations of high priority areas. Based on historical data, prioritize
specific geographic areas and/ or incident type for pro-active investigations.
Reporting
■ A database is useful for defining and tracking the magnitude and location of the problem.
■ Report prohibited non-stormwater discharges observed during the course of normal daily
activities so they can be investigated, contained, and cleaned up or eliminated.
■ Document that non-stormwater discharges have been eliminated by recording tests
performed, methods used, dates of testing, and any on-site drainage points observed.
■ Document and report annually the results of the program.
■ Maintain documentation of illicit connection and illegal dumping incidents, including
significant conditionally exempt discharges that are not properly managed.
Training
■ Training of technical staff in identifying and documenting illegal dumping incidents is
required.
■ Consider posting the quick reference table near storm drains to reinforce training.
■ Train employees to identify non-stormwater discharges and report discharges to the
appropriate departments.
4 of 6 California Stormwater BMP Handbook
Industrial and Commercial
www.cabmphandbooks.com
January 2003
Non-Stormwater Discharges SC-10
■ Educate employees about spill prevention and cleanup.
■ Well-trained employees can reduce human errors that lead to accidental releases or spills.
The employee should have the tools and knowledge to immediately begin cleaning up a spill
should one occur. Employees should be familiar with the Spill Prevention Control and
Countermeasure Plan.
■ Determine and implement appropriate outreach efforts to reduce non-permissible non-
stormwater discharges.
■ Conduct spill response drills annually (if no events occurred to evaluate your plan) in
cooperation with other industries.
■ When a responsible party is identified, educate the party on the impacts of his or her actions.
Spill Response and Prevention
■ See SC11 Spill Prevention Control and Cleanup.
Other Considerations
■ Many facilities do not have accurate, up-to-date schematic drawings.
Requirements
Costs (including capital and operation & maintenance)
■ The primary cost is for staff time and depends on how aggressively a program is
implemented.
■ Cost for containment and disposal is borne by the discharger.
■ Illicit connections can be difficult to locate especially if there is groundwater infiltration.
■ Indoor floor drains may require re-plumbing if cross-connections to storm drains are
detected.
Maintenance (including administrative and staffing)
■ Illegal dumping and illicit connection violations requires technical staff to detect and
investigate them.
Supplemental Information
Further Detail of the BMP
Illegal Dumping
■ Substances illegally dumped on streets and into the storm drain systems and creeks include
paints, used oil and other automotive fluids, construction debris, chemicals, fresh concrete,
leaves, grass clippings, and pet wastes. All of these wastes cause stormwater and receiving
water quality problems as well as clog the storm drain system itself.
■ Establish a system for tracking incidents. The system should be designed to identify the
following:
Illegal dumping hot spots
January 2003 California Stormwater BMP Handbook
Industrial and Commercial
www.cabmphandbooks.com
5 of 6
SC-10 Non-Stormwater Discharges
Types and quantities (in some cases) of wastes
Patterns in time of occurrence (time of day/night, month, or year)
Mode of dumping (abandoned containers, "midnight dumping" from moving vehicles,
direct dumping of materials, accidents/spills)
Responsible parties
One of the keys to success of reducing or eliminating illegal dumping is increasing the number of
people at the facility who are aware of the problem and who have the tools to at least identify the
incident, if not correct it. Therefore, train field staff to recognize and report the incidents.
What constitutes a "non-stormwater" discharge?
■ Non-stormwater discharges to the stormwater collection system may include any water used
directly in the manufacturing process (process wastewater), air conditioning condensate and
coolant, non-contact cooling water, cooling equipment condensate, outdoor secondary
containment water, vehicle and equipment wash water, sink and drinking fountain
wastewater, sanitary wastes, or other wastewaters.
Permit Requirements
■ Facilities subject to stormwater permit requirements must include a certification that the
stormwater collection system has been tested or evaluated for the presence of non-
stormwater discharges. The State's General Industrial Stormwater Permit requires that non-
stormwater discharges be eliminated prior to implementation of the facility's SWPPP.
Performance Evaluation
■ Review annually internal investigation results; assess whether goals were met and what
changes or improvements are necessary.
■ Obtain feedback from personnel assigned to respond to, or inspect for, illicit connections
and illegal dumping incidents.
References and Resources
California's Nonpoint Source Program Plan http://www.swrcb.ca.gov/nps/index.html
Clark County Storm Water Pollution Control Manual
http://www.co.clark.wa.us/pubworks/bmpman.pdf
King County Storm Water Pollution Control Manual http://dnr.metrokc.gov/wlr/dss/spcm.htm
Santa Clara Valley Urban Runoff Pollution Prevention Program http://www.scvurppp.org
The Storm Water Managers Resource Center http://www.stormwatercenter.net/
6 of 6 California Stormwater BMP Handbook
Industrial and Commercial
www.cabmphandbooks.com
January 2003
Vehicle and Equipment Cleaning SC-21
Photo Credit: Geoff Brosseau
Description
Wash water from vehicle and equipment cleaning activities
performed outdoors or in areas where wash water flows onto the
ground can contribute toxic hydrocarbons and other organic
compounds, oils and greases, nutrients, phosphates, heavy
metals, and suspended solids to stormwater runoff. Use of the
procedures outlined below can prevent or reduce the discharge of
pollutants to stormwater during vehicle and equipment cleaning.
Approach
Reduce potential for pollutant discharge through source control
pollution prevention and BMP implementation. Successful
implementation depends on effective training of employees on
applicable BMPs and general pollution prevention strategies and
objectives
Pollution Prevention
■ If possible, use properly maintained off-site commercial
washing and steam cleaning businesses whenever possible.
These businesses are better equipped to handle and properly
dispose of the wash waters.
■ Good housekeeping practices can minimize the risk of
contamination from wash water discharges.
January 2003 California Stormwater BMP Handbook
Industrial and Commercial
www.cabmphandbooks.com
Objectives
■ Cover
■ Contain
■ Educate
■ Reduce/Minimize
■ Product Substitution
Targeted Constituents
Sediment
Nutrients
Trash
Metals
Bacteria
Oil and Grease
Organics
✓
✓
✓
✓
✓
1 of 5
SC-21 Vehicle and Equipment Cleaning
Suggested Protocols
General
■ Use biodegradable, phosphate-free detergents for washing vehicles as appropriate.
■ Mark the area clearly as a wash area.
■ Post signs stating that only washing is allowed in wash area.
■ Provide trash container in wash area.
■ Map on-site storm drain locations to avoid discharges to the storm drain system.
■ Emphasize the connection between the storm drain system and runoff, help reinforce that
car washing activities affect local water quality through storm drain stenciling programs.
Vehicle and Equipment Cleaning
■ Have all vehicle washing done in areas designed to collect and hold the wash and rinse water
or effluent generated. Recycle, collect or treat wash water effluent prior to discharge to the
sanitary sewer system.
■ If washing/ cleaning must occur on-site, consider washing vehicle equipment inside the
building or on an impervious surface to control the targeted constituents by directing them
to the sanitary sewer.
■ If washing must occur on-site and outdoor:
Use designated paved wash areas. Designated wash areas must be well marked with
signs indicating where and how washing must be done. This area must be covered or
bermed to collect the wash water and graded to direct the wash water to a treatment or
disposal facility.
Do not conduct oil changes and other engine maintenance in the designated washing
area. Perform these activities in a place designated for oil change and maintenance
activities.
Cover the wash area when not in use to prevent contact with rain water.
■ Install sumps or drain lines to collect wash water for treatment.
■ Use hoses with nozzles that automatically turn off when left unattended.
■ Do not permit steam cleaning wash water to enter the storm drain.
■ Pressure and steam clean off-site to avoid generating runoff with high pollutant
concentrations. If done on-site, no pressure cleaning and steam cleaning should be done in
areas designated as wellhead protection areas for public water supply.
2 of 5 California Stormwater BMP Handbook
Industrial and Commercial
www.cabmphandbooks.com
January 2003
Drainage System Maintenance SC-44
Description
AB a consequence of its function, the stormwater conveyance
system collects and transports urban runoff and stormwater that
may contain certain pollutants. The protocols in this fact sheet
are intended to reduce pollutants reaching receiving waters
through proper conveyance system operation and maintenance.
Approach
Pollution Prevention
Maintain catch basins, stormwater inlets, and other stormwater
conveyance structures on a regular basis to remove pollutants,
reduce high pollutant concentrations during the first flush of
storms, prevent clogging of the downstream conveyance system,
restore catch basins' sediment trapping capacity, and ensure the
system functions properly hydraulically to avoid flooding.
Suggested Protocols
Catch Basins/Inlet Structures
■ Staff should regularly inspect facilities to ensure compliance
with the following:
Immediate repair of any deterioration threatening
structural integrity.
Cleaning before the sump is 40% full. Catch basins
should be cleaned as frequently as needed to meet this
standard.
Stenciling of catch basins and inlets (see SC34 Waste
Handling and Disposal).
January 2003 California Stormwater BMP Handbook
Industrial and Commercial
www.cabmphandbooks.com
Objectives
■ Cover
■ Contain
■ Educate
■ Reduce/Minimize
Targeted Constituents
Sediment ✓
Nutrients
Trash ✓
Metals
Bacteria ✓
Oil and Grease
Organics
Association
1 of 6
SC-44 Drainage System Maintenance
■ Clean catch basins, storm drain inlets, and other conveyance structures before the wet
season to remove sediments and debris accumulated during the summer.
■ Conduct inspections more frequently during the wet season for problem areas where
sediment or trash accumulates more often. Clean and repair as needed.
■ Keep accurate logs of the number of catch basins cleaned.
■ Store wastes collected from cleaning activities of the drainage system in appropriate
containers or temporary storage sites in a manner that prevents discharge to the storm
drain.
■ Dewater the wastes if necessary with outflow into the sanitary sewer if permitted. Water
should be treated with an appropriate filtering device prior to discharge to the sanitary
sewer. If discharge to the sanitary sewer is not allowed, water should be pumped or
vacuumed to a tank and properly disposed. Do not dewater near a storm drain or stream.
Storm Drain Conveyance System
■ Locate reaches of storm drain with deposit problems and develop a flushing schedule that
keeps the pipe clear of excessive buildup.
■ Collect and pump flushed effluent to the sanitary sewer for treatment whenever possible.
Pump Stations
■ Clean all storm drain pump stations prior to the wet season to remove silt and trash.
■ Do not allow discharge to reach the storm drain system when cleaning a storm drain pump
station or other facility.
■ Conduct routine maintenance at each pump station.
■ Inspect, clean, and repair as necessary all outlet structures prior to the wet season.
Open Channel
■ Modify storm channel characteristics to improve channel hydraulics, increase pollutant
removals, and enhance channel/ creek aesthetic and habitat value.
■ Conduct channel modification/improvement in accordance with existing laws. Any person,
government agency, or public utility proposing an activity that will change the natural
( emphasis added) state of any river, stream, or lake in California, must enter into a Steam or
Lake Alteration Agreement with the Department of Fish and Game. The developer-applicant
should also contact local governments (city, county, special districts), other state agencies
(SWRCB, RWQCB, Department of Forestry, Department of Water Resources), and Federal
Corps of Engineers and USFWS.
Illicit Connections and Discharges
■ Look for evidence of illegal discharges or illicit connections during routine maintenance of
conveyance system and drainage structures:
2 of 6
Is there evidence of spills such as paints, discoloring, etc?
California Stormwater BMP Handbook
Industrial and Commercial
www.cabmphandbooks.com
January 2003
Drainage System Maintenance SC-44
Are there any odors associated with the drainage system?
Record locations of apparent illegal discharges/illicit connections?
Track flows back to potential dischargers and conduct aboveground inspections. This
can be done through visual inspection of upgradient manholes or alternate techniques
including zinc chloride smoke testing, fluorometric dye testing, physical inspection
testing, or television camera inspection.
Eliminate the discharge once the origin of flow is established.
■ Stencil or demarcate storm drains, where applicable, to prevent illegal disposal of pollutants.
Storm drain inlets should have messages such as "Dump No Waste Drains to Stream"
stenciled next to them to warn against ignorant or intentional dumping of pollutants into the
storm drainage system.
■ Refer to fact sheet SC-10 Non-Stormwater Discharges.
Illegal Dumping
■ Inspect and clean up hot spots and other storm drainage areas regularly where illegal
dumping and disposal occurs.
■ Establish a system for tracking incidents. The system should be designed to identify the
following:
Illegal dumping hot spots
Types and quantities (in some cases) of wastes
Patterns in time of occurrence (time of day/night, month, or year)
Mode of dumping (abandoned containers, "midnight dumping" from moving vehicles,
direct dumping of materials, accidents/spills)
Responsible parties
■ Post "No Dumping" signs in problem areas with a phone number for reporting dumping and
disposal. Signs should also indicate fines and penalties for illegal dumping.
■ Refer to fact sheet SC-10 Non-Stormwater Discharges.
Training
■ Train crews in proper maintenance activities, including record keeping and disposal.
■ Allow only properly trained individuals to handle hazardous materials/wastes.
■ Have staff involved in detection and removal of illicit connections trained in the following:
OSHA-required Health and Safety Training (29 CFR 1910.120) plus annual refresher
training (as needed).
January 2003 California Stormwater BMP Handbook
Industrial and Commercial
www.cabmphandbooks.com
3 of 6
SC-44 Drainage System Maintenance
OSHA Confined Space Entry training (Cal-OSHA Confined Space, Title 8 and Federal
OSHA 29 CFR 1910.146).
Procedural training (field screening, sampling, smoke/dye testing, TV inspection).
Spill Response and Prevention
■ Investigate all reports of spills, leaks, and/or illegal dumping promptly.
■ Clean up all spills and leaks using "dry" methods (with absorbent materials and/or rags) or
dig up, remove, and properly dispose of contaminated soil.
■ Refer to fact sheet SC-11 Spill Prevention, Control, and Cleanup.
Other Considerations (Limitations and Regulations)
■ Clean-up activities may create a slight disturbance for local aquatic species. Access to items
and material on private property may be limited. Trade-offs may exist between channel
hydraulics and water quality/riparian habitat. If storm channels or basins are recognized as
wetlands, many activities, including maintenance, may be subject to regulation and
permitting.
■ Storm drain flushing is most effective in small diameter pipes (36-inch diameter pipe or less,
depending on water supply and sediment collection capacity). Other considerations
associated with storm drain flushing may include the availability of a water source, finding a
downstream area to collect sediments, liquid/sediment disposal, and prohibition against
disposal of flushed effluent to sanitary sewer in some areas.
■ Regulations may include adoption of substantial penalties for illegal dumping and disposal.
■ Local municipal codes may include sections prohibiting discharge of soil, debris, refuse,
hazardous wastes, and other pollutants into the storm drain system.
Requirements
Costs
■ An aggressive catch basin cleaning program could require a significant capital and O&M
budget.
■ The elimination of illegal dumping is dependent on the availability, convenience, and cost of
alternative means of disposal. The primary cost is for staff time. Cost depends on how
aggressively a program is implemented. Other cost considerations for an illegal dumping
program include:
4 of 6
Purchase and installation of signs.
Rental of vehicle(s) to haul illegally-disposed items and material to landfills.
Rental of heavy equipment to remove larger items (e.g., car bodies) from channels.
Purchase of landfill space to dispose of illegally-dumped items and material.
California Stormwater BMP Handbook
Industrial and Commercial
www.cabmphandbooks.com
January 2003
Drainage System Maintenance SC-44
■ Methods used for illicit connection detection (smoke testing, dye testing, visual inspection,
and flow monitoring) can be costly and time-consuming. Site-specific factors, such as the
level of impervious area, the density and ages of buildings, and type of land use will
determine the level of investigation necessary.
Maintenance
■ Two-person teams may be required to clean catch basins with vactor trucks.
■ Teams of at least two people plus administrative personnel are required to identify illicit
discharges, depending on the complexity of the storm sewer system.
■ Arrangements must be made for proper disposal of collected wastes.
■ Technical staff are required to detect and investigate illegal dumping violations.
Supplemental Information
Further Detail of the BMP
Storm Drain Flushing
Flushing is a common maintenance activity used to improve pipe hydraulics and to remove
pollutants in storm drainage systems. Flushing may be designed to hydraulically convey
accumulated material to strategic locations, such as an open channel, another point where
flushing will be initiated, or the sanitary sewer and the treatment facilities, thus preventing
resuspension and overflow of a portion of the solids during storm events. Flushing prevents
"plug flow" discharges of concentrated pollutant loadings and sediments. Deposits can hinder
the designed conveyance capacity of the storm drain system and potentially cause backwater
conditions in severe cases of clogging.
Storm drain flushing usually takes place along segments of pipe with grades that are too flat to
maintain adequate velocity to keep particles in suspension. An upstream manhole is selected to
place an inflatable device that temporarily plugs the pipe. Further upstream, water is pumped
into the line to create a flushing wave. When the upstream reach of pipe is sufficiently full to
cause a flushing wave, the inflated device is rapidly deflated with the assistance of a vacuum
pump, thereby releasing the backed up water and resulting in the cleaning of the storm drain
segment.
To further reduce impacts of stormwater pollution, a second inflatable device placed well
downstream may be used to recollect the water after the force of the flushing wave has
dissipated. A pump may then be used to transfer the water and accumulated material to the
sanitary sewer for treatment. In some cases, an interceptor structure may be more practical or
required to recollect the flushed waters.
It has been found that cleansing efficiency of periodic flush waves is dependent upon flush
volume, flush discharge rate, sewer slope, sewer length, sewer flow rate, sewer diameter, and
population density. As a rule of thumb, the length ofline to be flushed should not exceed 700
feet. At this maximum recommended length, the percent removal efficiency ranges between 65-
75% for organics and 55-65% for dry weather grit/inorganic material. The percent removal
efficiency drops rapidly beyond that. Water is commonly supplied by a water truck, but fire
hydrants can also supply water. To make the best use of water, it is recommended that
reclaimed water be used or that fire hydrant line flushing coincide with storm sewer flushing.
January 2003 California Stormwater BMP Handbook
Industrial and Commercial
www.cabmphandbooks.com
5 of 6
SC-44 Drainage System Maintenance
References and Resources
California's Nonpoint Source Program Plan http://www.swrcb.ca.gov/nps/index.html
Clark County Storm Water Pollution Control Manual
http://www.co.clark.wa.us/pubworks/bmpman.pdf
Ferguson, B.K. 1991. Urban Stream Reclamation, p. 324-322, Journal of Soil and Water
Conservation.
King County Storm Water Pollution Control Manual http://dnr.metrokc.gov/wlr/dss/spcm.htm
Oregon Association of Clean Water Agencies. Oregon Municipal Stormwater Toolbox for
Maintenance Practices. June 1998.
Santa Clara Valley Urban Runoff Pollution Prevention Program http: //www.scvurppp.org
The Storm Water Managers Resource Center http://www.stormwatercenter.net
United States Environmental Protection Agency (USEPA). 2002. Pollution Prevention/Good
Housekeeping for Municipal Operations Storm Drain System Cleaning. On line:
http://www.epa.gov/npdes/menuofbmps/poll 16.htm
6 of 6 California Stormwater BMP Handbook
Industrial and Commercial
www.cabmphandbooks.com
January 2003
Appendix E: BMP Design Fact Sheets
E-57 February 2016
E.11 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
Appendix E: BMP Design Fact Sheets
E-58 February 2016
Typical plan and Section view of a Biofiltration with Partial Retention BMP
CURB cut} ,' •, •
12" MIN. :.:'.:
}~-.. ;..~~::: .
>}}::
(~;)_;} .~
+ + + + ., .,
PRON
ISSIPA
.,3H:1V (MIN ) "'
+ + + +
+ + + +
+ + + +
+ + + +
MAINTENANCE .,
ACCESS
JAS !"EE?EDJ "'
+ + + +
3H:1V (MIN.) .,
<<\ .. < ~
VEGETATED
SIDE SLOPE
PLAN
NOTTO SCALE
4-6" DROP FROM CURB CUT TO APRON
APRON FOR ENERGY DISSIPATION
EXCAVATED SLOPE
(SHOWN AT 1H:1V)
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
2" MIN. F RD
OVERFLOW
STRUCTURE
UNDERDRAIN
FILTER COURSE
EXISTING UNCOMPACTED SOILS
SECTION A-A'
NOTTO SCALE
MAINTENANCE
ACCESS
(AS NEEDED)
Appendix E: BMP Design Fact Sheets
E-59 February 2016
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.
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:
Siting and Design 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 C and
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
Appendix E: BMP Design Fact Sheets
E-60 February 2016
Siting and Design Intent/Rationale
design features requested by the City
Engineer for proper performance of the
regional BMP.
□ Finish grade of the facility is ≤ 2%. Flatter surfaces reduce erosion and
channelization within the facility.
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.
□ Surface ponding depth is ≥ 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.
□ A minimum of 2 inches of freeboard is
provided.
Freeboard provides room for head over
overflow structures and minimizes risk
of uncontrolled surface discharge.
□ Side slopes are stabilized with vegetation and
are = 3H:1V or shallower.
Gentler side slopes are safer, less prone
to erosion, able to establish vegetation
more quickly and easier to maintain.
Vegetation
Appendix E: BMP Design Fact Sheets
E-61 February 2016
Siting and Design Intent/Rationale
□ Plantings are suitable for the climate and
expected ponding depth. A plant list to aid in
selection can be found in Appendix E.20
Plants suited to the climate and ponding
depth are more likely to survive.
□ 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:
City of San Diego Storm Water Standards
Appendix F (February 2016, unless superseded
by more recent edition) or County of San
Diego Low Impact Development Handbook:
Appendix G -Bioretention Soil Specification
(June 2014, unless superseded by more recent
edition).
Alternatively, for proprietary designs and
custom media mixes not meeting the media
specifications contained in the 2016 City of San
Diego Storm Water Standards or County LID
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.
Appendix E: BMP Design Fact Sheets
E-62 February 2016
Siting and Design Intent/Rationale
Manual, the media meets the pollutant
treatment performance criteria in Section F.1.
□ Media surface area is 3% of contributing area
times adjusted runoff factor or greater.
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
of the BMP (such as rain barrels,
impervious area dispersion, etc.). Refer
to Appendix B.2 guidance.
Use Worksheet B.5-1 Line 26 to estimate
the minimum surface area required per
this criteria.
□
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
Appendix E: BMP Design Fact Sheets
E-63 February 2016
Siting and Design Intent/Rationale
□
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.
□ 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 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.
Appendix E: BMP Design Fact Sheets
E-64 February 2016
Siting and Design Intent/Rationale
□
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.
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.5. 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
Appendix E: BMP Design Fact Sheets
E-65 February 2016
requirements, calculations must be completed to verify if storm water pollutant control
requirements to treat the DCV have been met.
ATTACHMENT 4
City standard Single Sheet BMP (SSBMP) Exhibit
[Use the City’s standard Single Sheet BMP Plan.]
DMA 1
H
O
O
V
E
R D
RIV
E
A D A M S S T R E E T
P RIV A T E D RIV E W A Y
DMA 2
DMA 3
DMA 4.1
DMA 4.2
DMA 4.3
DMA 5
PR-1-1
PR-1-2
PR-1-3
PARCEL 1
PARCEL 2
PARCEL 3
***
ROOF DRAIN TOLANDSCAPING4
1. THESE BMPS ARE MANDATORY TO BE INSTALLED PER MANUFACTURER'S
RECOMMENDATIONS OR 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.
BMP NOTES:
PARTY RESPONSIBLE FOR MAINTENANCE:
NAME
ADDRESS
PHONE NO.
PLAN PREPARED BY:
NAME
ADDRESS
PHONE NO.
CERTIFICATION
COMPANY
SD-11
LOW IMPACT DESIGN (L.I.D.)
6
5. REFER TO MAINTENANCE AGREEMENT DOCUMENT.
TBD EA.ANNUALLY ANNUALLY
6. SEE PROJECT SWMP FOR ADDITIONAL INFORMATION.
SIGNATURE
BMP CONSTRUCTION AND INSPECTION NOTES:
THE EOW WILL VERIFY THAT PERMANENT BMPS 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.
HENRY OLIVIER
P.O. BOX 9493
SAN BERNARDINO, CA 92427
951-232-4378
JOHN S. RIVERA
FUSION ENG. & TECH.
1810 GILLESPIE WAY SUITE 207
EL CAJON, CA 92117
619-736-2800
1
SWQMP NO.________________16-07
MAINTENANCE AGREEMENT DOCUMENT: YES___ NO___
RECORDATION NO. __________________MS 02-05
X
BMP TYPEBMP ID #SYMBOL CASQA NO.DRAWING NO.SHEET NO.(S)MAINTENANCE
FREQUENCY
BMP TABLE
INSPECTION
FREQUENCYQUANTITY
TREATMENT CONTROL
PR-1-1
PARTIAL RETENTION SEMI-ANNUALLY438-2A 3
**
ANNUALLYBY BIOFILTRATION
PR-1-2
PR-1-3 *
FUTURE PGP
438-2AFUTURE PGP
438-2AFUTURE PGP
1 EA.261 S.F.
1 EA.256 S.F.
1 EA.218 S.F.
SEMI-ANNUALLY3 ANNUALLY
SEMI-ANNUALLY3 ANNUALLY
TC-32 / FT-4
PER REQUEST OF CITY OF CARLSBAD TEMP SEDIMENT BASINS WILL BE PROVIDED WITHIN THE FOOTPRINT OF THE ASSUMED FUTURE
BIORETENTION BASIN.
THE TEMP SEDIMENT BASIN WILL BE PROVIDED IN ADDITION TO THE STANDARD EROSION CONTROL CONSTRUCTION BMP'S PROVIDED
FOR TYPICAL SINGLE FAMILY GRADED PADS.
FUTURE BIORETENTION BASINS TO BE CONSTRUCTED WITH DEVELOPMENT OF LOTS.
**TC-32 / FT-4
TC-32 / FT-4
ONSITE STORMDRAIN INLETS7 SD-13
SOURCE CONTROL
9 3 EA.3 ANNUALLY ANNUALLY
2
3
1 2
9
4
5
6
3
8
7
FUTURE PGP TBD
438-2A
PERMANENT WATER QUALITY
TREATMENT FACILITY
WATER QUALITY SIGN
BMP SITE PLAN
PARTIAL RETENTIONBY BIOFILTRATION
PARTIAL RETENTIONBY BIOFILTRATION
FUTURE PARTIAL RETENTION BY BIOFILTRATION BASIN
/
/
0.006 ACRES
~
7.5'
/
/
/
/
1
/ I
·-.,
""' y
/
/
/
/1 (
, 1
I
{
I 0.369 ACRES I
'ASSUMED
FUTURE
IMPERVIOUS
AREA O•
........_ -----<>--.
I
,, f I
I
·-.,. __ ,,,---f
/
I
C
~ ..... _ -~
'
""' '
""' '
\ ' / \ ,..------y ~---------------------~ ,V V ~ r /
I
I
I
I
I
q
' / V
a
,,. a
-
,.._ §:, a
L, , "',~.,._ a
..... --.;;; c-:::........_ -........ -..... ~=-----::=--i
/ /
............. --00........:::,.-----.:es~~~~~~-~~-~o~O~--,,.. -9 c:i ----
2:1 ,,,---/ ----
i
i
i -----
--·71
;
!
i
!
i
!
I
!
I
1
f
I
I
I
/B\ ( ) \ / \ __ /
•SEE TABLE AT
RIGHT FOR
ASSUMED FUTURE
IMPERVIOUS AREAS
j-------&---
/ .
/ f I 0.355 ACRES I
I I
I ' ~7"----,,t-/-'.._.j_l'__ ••ASSUMED
FUTURE
2:1
IMPERVIOUS ------~
AREA o•
----
-,
\
I
I
I
I
I
t
j
I I !!!I"===-+-~
I
I
I
I
I
I
-;;;; (
0/JTl.IT
0.006 ACRES
-
'
I.\ \
',c
----
I 0.378 ACRES I
'ASSUMED
FUTURE
IMPERVIOUS
AREA O•
----------
I
I
0.006 ACRES
11
q
PROPERTY
BOUNDARY
'l-
,-1--
\
""'
0 A o.036 ACREsL----------
I ;
I
BASIN ULTIMATE
FINISH GRADE
'
""' ' ~
®PROPOSED
12"X12" C.B.
FOR OVERFLOW
NOT TO SCALE
CONSlRUCTION NOTE
CONCEPTUAL WATER QUALITY BASIN TO BE INSTALLED IN FUTURE BY
OWNER ONCE PRECISE GRADING PERMITS ARE APPROVED FOR HOUSE
CONSTRUCTION.
w _J
CD 0
1o :s i'5 <( :r: >
<C 6.0'
BERM
u
20
CONSTRUCTION NOlES
A PERMANENT DURABLE SIGN WITH THE FOLLOWING LANGUAGE TO BE
PLACED IN FUTURE BIORETENTION BASIN.
"PERMANENT WATER QUALITY TREATMENT FACILITY
KEEPING OUR WATERWAYS CLEAN
MAINTAIN WITH CARE -NO MODIFICATIONS WITHOUT AGENCY APPROVAL"
IT SHALL BE PLACED ON A POLE OR PLACED ON A CONCRETE TILE OR
PLAQUE LIKE SURFACE FLUSH WITH BUT SLIGHTLY RAISED ABOVE
GROUND AT THE TOP OF THE BASIN SUBJECT TO THE CITY ENGINEER'S
DISCRETION.
Fusion Eng Tech
1810 Gillespie Way, Suite 207
El Cajon, CA 92020
(619) 736-2800
0 20 40 -----
SCALE 1"= 20'
24"
KEIP OUR WATERWAYS CLEAN
M/>JNTAIN WITH CARE
NO MODIFlCATIONS WITHOI/T AGENCY APPROVIJ.
NOT TO SCALE
DMA 1-PR
Runoff Summation
OMA Description DMA Type Factor % Imper Area (ac.} Area (s.f.) Runoff Factor
x Arc;;i (.le.)
Bioretention Bo~in Engineered Perviou~ Surface 0.10 0% 0.006 261 0.0006
Natural Slope Natural Type 'B' Soil 0.14 0% 0.065 2825 0.0091
Landscape Slope/ Pad Semi-Pervious Surface 0.30 0% 0.131 5692 0.0392
Roof/Ha rd sea pe/Driveway Impervious Surface 0.90 100% 0.168 7305 0.1509
Total Total A-roca1= 0.369 16083 0.1998
Total Total Ached= 0.369 RFcompo,ite-DMA= 0.54
DMA 2-PR
Runoff Summation
OMA Descriplion DMA Type Factor %Imper Area (ac.) Area (s.f.) Runoff Faclor
x Area (ac.)
Bioretention Basin Engineered Pervious Surface 0.10 0% 0.006 2SG 0.000G
Natural Slope Natural Type 'B' Soil 0.14 0% 0.059 2552 0.0082
Landscape Slope/ Pad Semi-Pervious Surface 0.30 O'½ 0.126 5499 0.0379
Roof/Ha rd sea pe/Driveway Impervious Surface 0.90 100'½ 0.165 7170 0.1481
Total Total ATuldl= 0.355 15477 0.1948
Total Total Ached= 0.355 RF composite-OMA;; 0.55
DMA 3-PR
Runoff Summation
DMA Descriplion DMA Type % Imper Area (ac.} Area (d.) Runoff Factor Factor x Area (ac.)
Bioretention Basin Engineered Pervious Surface 0.10 0% 0.005 218 0.0005
Natural Slope Natural Type 'B' Soil 0.14 O'½ 0.122 5302 0.0170
Landscape Slope/ Pad Semi-Pervious Surface 0.30 0% 0.128 5572 0.0384
Roof/Ha rdsca pe/Driveway Impervious Surface 0.90 100'½ 0.124 5390 0.1114
Total Total A-rma1= 0.378 0.378 0.1673
Total Total .\_:heck -0.378 RF composite-OM/\= 0.44
DMA 4-PR (DeMinimis, 250 s.f. per Lot Driveway Entrance)
Runoff Summation
DMA Description DMA Type Factor %Imper Are;:i (;:ic.} AreJ (s.f.) Runoff Factor
x Area (ac.)
Driveway (ROW) Impervious Surface 0.90 100'½ 0.017 750 0.0155
Tot,:11 Total ATotal= 0,017 750 0.0155
Tot,:11 Total A-.h•ck= 0,017 RFcomposlt~-CMA= 0.90
DMA 5-PR (Adams Street Widening Opposite Side of Project)
Runoff Summation
OMA Description DMA Type % Imper Area (ac.} Area (s.f.) Runoff Fcictor Factor x Area (ac.)
Pilvement (Adilms Street) Impervious Surface 0.90 100% 0.036 1558 0.0322
Total Total ATot~I= 0.036 1558 0.0322
Tola I Tolal A.check-0,036 RFcompo,1te-DMA= 0.90
Note: Roof/HJrdscJpc/Drivcw;:iy in table Jre projected impervious Jrc;:i for PIJnning purposes. ActuJI ;:ireas mJy v;:iry ;:ind require
adjustment to bioretention basin sizes during building permit phase
Note: DMA5 implements Greet Street design elements including impervious dispersion to pervious surface at edge of pavement.
60 0
0
0
0-0 •
0-0 ~
®
I S4ET I CITY OF CARLSBAD I SH4ETS I
ENGINEERING DEPARTMENT
BMP SITE PLAN FOR:
CARLSBAD OCEANVIEW ESTATES
GR-2016-0030 HDP02-04/CDP02-16
1 REVISE FROM PRECISE TO ROUGH GRADING
DA TE INITIAL
ENGINEER OF WORK REVISION DESCRIPTION
DATE INITIAL DATE INITIAL
OTHER APPROVAL CITY APPROVAL
DWN BY: '~ □ I PROJECT NO.
I
DRAWING NO.
CHKD BY: MS-02-05 438-2SW
RVWD BY: