HomeMy WebLinkAboutCT 12-05; LA COSTA RESIDENTIAL; STORM WATER MANAGEMENT PLAN; 2013-07-16STORM WATER MANAGEMENT PLAN
FOR
LA COSTA RESIDENTIAL
(CT 12-05, PUD 12-07, SWMP 13.07, Drawing 477-9A)
July 16, 2013
Wayne W. Chang, MS,TE 46548
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Civil Engineering»Hydrology»Hydraulics»Sedimentation
P.O. Box 9496
Rancho Santa Fe, CA 92067
(858) 692-0760
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-TABLE OF CONTENTS -
1.0 Introduction 1
1.1 Vicinity Map 1
1.2 Project Description 2
1.3 Site Map 2
1.4 Constraints and Opportunities 2
2.0 Water Quality Environment 3
2.1 Beneficial Uses 3
2.1.1 Inland Surface Waters 4
2.1.2 Groundwater 4
3.0 Pollutants and Conditions of Concern 4
3.1 Pollutants from Project Area 4
3.2 Pollutants of Concern in Receiving Waters 5
4.0 Permanent Storm Water Best Management Practices 6
4.1 Standard Site Design BMPs 6
4.2 Source Control BMPs 7
4.3 Low Impact Development Site Design BMPs 9
4.4 Treatment Control BMPs 9
4.5 Hydromodification 9
5.0 Storm Water BMP Maintenance 11
6.0 Summary/Conclusions 12
7.0 Certification 12
Storm Water Standards Questionnaire, E-34
Site Map
BMP Site Plan
APPENDIX
A. Low Impact Development and Hydromodification Analyses
1.0 INTRODUCTION
This Storm Water Management Plan (SWMP) addresses water quality requirements
associated with the La Costa Town Square project, which is a proposed residential
subdivision in the city of Carlsbad. This SWMP accompanies the final engineering plans by
the project's civil engineer, Latitude 33, and follows the criteria outlined in the City of
Carlsbad's January 14, 2011, Standard Urban Storm Water Management Plan (SUSMP).
According to the City's Storm Water Standards Questionnaire E-34 (attached following this
report text), the development is in the following three priority project categories: Housing
subdivisions of 10 or more dwelling units; Streets, roads, highways, and freeways; and More
than 1-acre of disturbance. The SUSMP outlines the SWMP objectives, which are to identify
site opportunities and constraints, identify pollutants and conditions of concern, follow low
impact development design objectives, describe best management practices (BMPs), and
outline maintenance requirements. BMPs will be utilized to the maximum extent practicable
to provide a long-term solution for addressing runoff water quality. BMPs were selected by
Latitude 33 to meet the objectives.
1.1 Vicinity Map
VICINITY MAP
CfTY OF OCEANSIDE
HWHWWrt^
CITY OF SAN MARCOS
PAanc
OCEAN
PROJECT SITE
CITY OF ENaNITAS
1.2 Project Description
The La Costa Town Square project is a proposed residential subdivision that will consist of
32 detached single-family residences along with associated driveways, sidewalks,
landscaping, and drainage facilities (see the Site Map following this report text). The
development will be constructed within an undeveloped 9.9 acre parcel along the north side
of Rancho Santa Fe Road and west of Paseo Lupino.
Under pre-project conditions, the site is mostly pervious and covered with vegetation or bare
soil. A nearly 5 acre development pad has been mass-graded within the site. As part of the
mass-grading, manufactured 2:1 slopes exist around the perimeter of the pad. The triangular-
shaped pad is higher than the adjacent ground to the northwest and south, and both higher
and lower than the adjacent ground to the east. The pad is primarily gently sloping towards
an existing desiltation basin at its southwest corner. An existing storm drain pipe conveys
storm runoff out of the desiltation basin and away from the site. The off-site storm drain
system continues in a northwesterly direction for over half a mile and ultimately outlets into
a natural canyon that flows into San Marcos Creek just east of the east end of the La Costa
Resort & Spa's South (golf) Course. San Marcos Creek continues westerly through the golf
course where it discharges into Batiquitos Lagoon.
A small area of pre-project runoff from the development pad will flow easterly down the site
entrance and onto Paseo Lupino. An existing curb inlet along the west side of Paseo Lupino
about 70 feet south of the site entrance near Rancho Santa Fe Road captures this runoff.
Under post-project conditions, the on-site runoff will be conveyed in a southwesterly
direction in streets and drainage facilities and ultimately enter the existing storm drain system
near the southwest corner of the project area. A small area near the northerly corner of the
project will flow into an existing concrete drainage ditch that conveys runoff in a
southwesterly direction along the northerly toe of slope of the pad. The ditch ultimately
directs its runoff into the existing storm drain system near the southwest corner of the project
area. The on-site proposed condition runoff from these areas will enter one of five
bioretention basins for treatment and hydromodification control prior to leaving the site. In
addition, some of the bioretention basins will also be used for detention.
A small portion of Paseo Lupino near the site entrance will contain pervious pavers. Lot 1
and a portion of Lot 2 are adjacent to and flow towards the pavers. The water quality runoff
from these lots and pavers will be conveyed then collected by a trench drain crossing the site
entrance. The trench drain will convey the runoff north into BMP 3.
1.3 Site Map
A Site Map is included following this report text.
1.4 Constraints and Opportunities
As shown on the site map, the development will occur within a previously mass-graded pad
intended for development. The pre-project drainage patterns are being maintained by the
project.
The development will consist of detached single-family residences surrounded by gently
sloping landscape areas and some shared drive aisles. The landscape areas provide
opportunities to treat runoff through contact and bio-filtration by vegetation. For several of
the residences, shared drive aisles will be used to minimize impervious surfaces. Bioretention
basins are proposed at five areas within the development area. The bioretention basins will be
used to meet both treatment and hydromodification requirements. Latitude 33's plans contain
more details on the bioretention basins.
2.0 WATER QUALITY ENVIRONMENT
2.1 Beneficial Uses
The beneficial uses for the hydrologic unit (see Section 3.1) are included in Tables 1 and 2.
These tables were obtained from the Water Quality Control Plan for the San Diego Basin (9)
compiled on August 28, 2012. The following contains definitions of the beneficial uses in the
tables:
MUN - Municipal and Domestic Supply: Includes uses of water for community,
military, or individual water supply systems including, but not limited to, drinking
water supply.
AGR - Agricultural Supply (AGR): Includes uses of water for farming,
horticulture, or ranching including, but not limited to, irrigation, stock watering, or
support of vegetation for range grazing.
RECl - Contact Recreation: Includes uses of water for recreational activities
involving body contact with water, where ingestion of water is reasonably possible.
These uses include, but are not limited to, swimming, wading, water-skiing, skin and
SCUBA diving, surfing, white water activities, fishing, or use of natural hot springs.
REC2 - Non-Contact Recreation: Includes the uses of water for recreational
involving proximity to water, but not normally involving body contact with water,
where ingestion of water is reasonably possible. These uses include, but are not
limited to, picnicking, sunbathing, hiking, camping, boating, tide pool and marine life
study, hunting, sightseeing, or aesthetic enjoyment in conjunction with the above
activities.
WARM - Warm Freshwater Habitat: Includes uses of water that support warm
water ecosystems including, but not limited to, preservation or enhancement of
aquatic habitats, vegetation, fish or wildlife, including invertebrates.
WILD - Wildlife Habitat: Includes uses of water that support terrestrial ecosystems
including, but not limited to, preservation and enhancement of terrestrial habitats.
vegetation, wildlife, (e.g., mammals, birds, reptiles, amphibians, invertebrates), or
wildlife water and food sources.
2.1.1 Inland Surface Waters
Inland surface waters for the San Marcos Hydrologic Area (see Section 3.1) have the
beneficial uses shown in Table 1:
Table 1. Beneficial Uses for Inland Surface Waters
Hydrologic
Unit o u Code c o
2 o o o u cs o
(U
;M
CO < O Oi m U (/I
904.51 + • • • • •
+ Exempted by the Regional Board from the municipal used designation.
• Existing Beneficial Use
2.1.2 Groundwater
Groundwater beneficial uses for the El Salto Hydrologic Subarea are shown in Table 2:
Table 2. Beneficial Uses for Groundwater
Hydrologic
Unit
Code c O Mu < Pro o
904.51 • • •
• Existing Beneficial Use
3.0 POLLUTANTS AND CONDITIONS OF CONCERN
3.1 Pollutants from Project Area
The project is located within the Batiquitos Hydrologic Subarea (904.51) of the San Marcos
Hydrologic Area (904.50), which is within the Carlsbad Hydrologic Unit (904.00). The total
drainage area of the hydrologic unit is approximately 210 square miles. Runoff from portions
of the hydrologic subarea ultimately drains to Batiquitos Lagoon, which is west of the project
site. All of the project runoff will ultimately enter Batiquitos Lagoon. The project site
represents less than one percent of the overall watershed.
The following table lists pollutants of concern that are anticipated or can potentially exist at
proposed priority development project sites. The pollutants are from the city of Carlsbad's
SUSMP. The project falls within the detached residential development and streets, highways
& freeways priority project categories (highlighted yellow in the table). All of the listed
pollutants are either anticipated or can potentially exist at the developed site.
Table 3. Priority Project Pollutants
Priority
Project
Categories
Sediments Nutrients Heavy
Metals
Organic
Compounds
Trash
&
Debris
Oxygen
Demanding
Substances
Oil
&
Grease
Bacteria
&
Viruses
Pesticides
Detached
Residential
Development
X X X X X X X
Attached
Residential
Development
X X X p(i) p(2) P X
Commercial
Development
> one acre
p<i) p(i) X p(2) X p(5) X p{3) p(5)
Heavy
Industry X X X X X X
Automotive
Repair Shops X X X
Restaurants X X X X p(l)
Hillside
Development
>5,000 fl^
X X X X X X
Parking Lots p(l) p(0 X X p(l) X p(l)
Retail
Gasoline
Outlets
X X X X X
Streets,
Highways &
Freeways
X p(l) X X p(5) X X p(l)
X = Anticipated
P = Potential
(1) A potential pollutant if landscaping exists on-site
(2) A potential pollutant if the project includes uncovered parking areas
(3) A potential pollutant if land use involves food or animal waste products
(4) Including petroleum hydrocarbons
(5) Including solvents
3.2 Pollutants of Concern in Receiving Waters
The receiving waters for the site include Encinitas Creek (small amount of on-site runoff
tributary to curb inlet in Paseo Lucindo), San Marcos Creek (on-site runoff from remainder
of site), and Batiquitos Lagoon (entire site). According to the 2008 303(d) list approved by
the State Water Resources Control Board (and by the US EPA in November 2010), Encinitas
Creek is 303(d) listed for phosphorus, selenium, and toxicity. San Marcos Creek is 303(d)
listed for DDE, phosphorus, sediment toxicity, and selenium. Batiquitos Lagoon, is not
303(d) listed. None of the three water bodies is subject to total maximum daily loads
(TMDLs). Based on this information, the project generates pollutants of concern in the
receiving waters for sediment and nutrients (phosphorus).
4.0 PERMANENT STORM WATER BEST MANAGEMENT PRACTICES
To address water quality for the project, best management practices (BMPs) will be
implemented. The following discusses the Standard Site Design, Source Control, and Low
Impact Development design BMPs for the project.
4.1 Standard Site Design BMPs
The City of Carlsbad's standard objectives are required for all projects. The project will
accomplish these goals through the following standard site design BMPs, which are from the
Carlsbad SUSMP:
Standard Stormwater Requirements
Minimize Impervious Surfaces. The project will include pervious surfaces through
landscaping within the development area. The project will not disturb the majority of the
natural areas beyond the previously mass-graded development pad.
Disconnect Discharges. Roof drains will discharge to adjacent landscape areas, where
feasible. The proposed sidewalks along the private cul-de-sac street within the site are being
designed with a landscaped parkway between the sidewalks and curbs to allow runoff to
drain over adjacent landscape areas.
Conserve Natural Areas. The majority of the areas beyond the perimeter of the mass-graded
pad will not be disturbed by the project.
Stenciling Inlets and Signage. The curb cuts and inlets within the project will be stenciled
with prohibitive language such as "No Dumping -1 live downstream" or approved similar.
landscape Design. A landscape plan will be prepared that uses drought-tolerant species in
accordance with the City's landscape manual. Native trees and shrubs will be preserved
beyond the majority of the mass-graded pad in order to maximize canopy interception and
promote water conservation. The project will only use water as needed to support the
landscaping.
Water Efficient Irrigation. The irrigation systems will be designed to each landscaped areas
water requirements to avoid over irrigation. Rain shutoff devices will be used to prevent
irrigation after rain events.
Protect Slopes And Channels. The grading design does not include large slopes or any
channels. The design will prevent runoff from flowing uncontrolled over the tops of
manufactured slopes. The proposed slopes will be landscaped. Riprap energy dissipaters will
be used at storm drain outfalls.
Vegetate slopes with native or drought tolerant vegetation. Native and drought tolerant
vegetation will be used to the extent feasible.
Trash Receptacles. Each residence will have personal, covered trash receptacles.
Material Storage Areas. The project does not propose outdoor material storage areas. Any
required material storage shall be kept under cover.
4.2 Source Control BMPs
Source control BMPs will consist of measures to prevent polluted runoff. The following
addresses the source control BMPs from Appendix 1 of the Carlsbad SUSMP:
Table 4. Pollutant Sources and Source Control Checklist
Potential Source
of Runoff Pollutants
Permanent Source
Control BMPs
Operational Source
Control BMPs
On-site storm drain
inlets
Mark all inlets with "No
Dumping -1 live downstream'
Maintain and periodically
repaint inlet markings
Provide stormwater pollution
information to owners, lessees,
and operators (Fact sheet SC-
44 from the CASQA
Stormwater Quality Handbook
at www.cabmphandbooks.com)
Owner/lessee agreements shall
state "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.
Need for future
indoor & structural
pest control
Buildings shall be designed to
avoid openings that would
encourage entry of pests.
Integrated Pest Management (e.g.,
the EPA's Citizen's Guide to Pest
Control and Pesticide Safety)
information shall be provided to
owners, lessees, and operators.
Landscape/Outdoor
Pesticide Use
Final landscape plans will
accomplish all of the
following.
• Preserve existing native trees,
shrubs, and ground cover to
the maximum extent possible.
• Design landscaping to
minimize irrigation and
runoff, to promote surface
infiltration where
appropriate, and to minimize
the use of fertilizers and
pesticides that can contribute
Maintain landscaping using
minimum or no pesticides.
See applicable operational BMPs
in Fact Sheet SC-41, "Building and
Grounds Maintenance," and TC-
30, "Vegetated Swale," in the
CASQA Stormwater Quality
Handbooks at
www.cabmphandbooks .com
Integrated Pest Management (e.g.,
the EPA's Citizen's Guide to Pest
Control and Pesticide Safety)
information shall be provided to
owners, lessees, and operators.
to stormwater pollution.
• Where landscaped areas can
retain or detain stormwater,
specify plants that are
tolerant of saturated soil
conditions.
• Consider using pest-resistant
plants, especially adjacent to
hardscape.
• To ensure successful
establishment, select plants
appropriate to site soils,
slopes, climate, sun, wind,
rain, land use, air movement,
ecological consistency, and
plant interactions
Vehicle and
equipment cleaning
The CC&Rs will define car
washing requirements and
restrictions at the site. The
HOA will be responsible for
enforcing the requirements and
restrictions.
Vehicle/Equipment
Repair and
Maintenance
The CC&Rs will prohibit
repair and maintenance
activities in areas exposed to
precipitation and storm flows.
The HOA will be responsible
for enforcing this requirement.
Roofing, gutters, and
trim
The architectural design will
avoid roofing, gutters, and trim
made of copper or other
unprotected metals that may
leach into runoff.
Plazas, sidewalks,
and parking lots.
Plazas, sidewalks, and parking lots
shall be swept regularly to prevent
the accumulation of litter and
debris. Debris from pressure
washing shall be collected to
prevent entry into the storm drain
system. Wash water containing
any cleaning agent or degreaser
shall be collected and discharged
to the sanitary sewer and not
discharged to a storm drain.
4.3 Low Impact Development Site Design BMPs
Low Impact Development (LID) BMPs must be incorporated into the site design to meet the
City of Carlsbad's January 14, 2011 SUSMP requirements. The integrated LID outlines five
strategies:
1. Optimize the site layout by preserving natural drainage features and designing
buildings and circulation to minimize the amount of roofs and paving.
2. Use pervious surfaces such as turf, gravel, or pervious pavement—or use surfaces that
retain rainfall. All drainage from these surfaces is considered to be "self-retained".
3. Disperse runoff from impervious surfaces on to adjacent pervious surfaces (e.g.,
direct a roof downspout to disperse runoff onto a lawn).
4. Drain impervious surfaces to engineered Integrated Management Practices (IMPs),
such as bioretention facilities. IMPs infiltrate runoff to groundwater and/or percolate
runoff through engineered soil and allow it to drain away slowly.
The project design is in compliance with these strategies. The site layout has been designed
to preserve natural areas beyond the mass-graded pad. Shared drive aisles will provide access
to many of the units and the on-site streets are being designed with minimal widths.
Runoff from the roofs will fiow towards pervious landscape areas, where possible, and
ultimately enter a bioretention basin. Bioretention basins will also be used to treat the
additional on-site runoff and to meet hydromodification requirements (discussed in next
section). Bioretention basins provide high to medium removal effectiveness for the pollutants
generated by the project, which are listed in Table 3. Sizing is included in Appendix A of this
report using County of San Diego's BMP Sizing Calculator.
4.4 Treatment Control BMPs
Treatment control BMPs were selected to treat the project pollutants of concern identified in
Table 3. Bioretention basins will be used because they have a medium to high pollutant
removal efficiency for the project's pollutants of concern. For treatment control only, a
bioretention basin's surface area must be at least 4 percent of the total area determined from
the Drainage Management Areas. For the project, the bioretention basins will also provide
hydromodification flow control. The sizing is discussed in the next section.
4.5 Hydromodification
The January 14, 2011 SUSMP requires hydromodification (flow control) for priority
development projects to ensure that post-development peak flows do not exceed pre-
development peak flows. La Costa Town Square is a priority development project and must
meet the hydromodification requirement. This can be accomplished by sizing bioretention
facilities using the criteria in the County of San Diego's SUSMP.
The proposed project will have five bioretention basins spread throughout the site (see the
Drainage Management Areas exhibit in Appendix A). The County's BMP Sizing Calculator
was used for the bioretention basin sizing.
Data entry for the BMP Sizing Calculator include the lower flow threshold, soil group, slope,
and rain gage. A lower flow threshold of 0.1 Q2 is used because a downstream channel
screening assessment has not been performed. The site is within the Oceanside rainfall basin
and contains soil group D. The average slope along the mass-graded pad is in the range of 1
to 2 percent, which is within the "flat" category.
The bioretention sizing analyses are included in Appendix A using the bioretention plus vault
option. The Drainage Management Areas (DMA) exhibit in Appendix A delineates the
drainage areas tributary to each of the five bioretention basins. Each drainage area is
subdivided into its roofs, asphalt (streets), concrete (sidewalks, driveways, patios), pervious
pavers, and landscaping. The BMP Sizing Calculator combines asphalt and concrete together
since these have the same runoff factor of 1.0. The results are included in Table 5. Table 5
contains the minimum treatment control surface area for bioretention as well as the necessary
storage volume and orifice sizing.
Table 5. Summary of Bioretention Sizing
BMP Sizing Calculator Results
Bioretention Surface Storage Orifice
Basin Area, sf Volume, cf Size, in
1 818 4,504 0.5
2 559 3,076 0.5
3 792 4,360 0.6
4 466 2,568 0.4
5 2,709 14,092 0.9
Note: Bioretention basins were sized using bioretention + vault
option.
Bioretention basins 1, 2, 3, 4, and 5 shown on the grading plans meet the surface area from
the BMP Sizing Calculator. Furthermore, the County of San Diego's Final HMP states that
the ponding layer and storage layer are converted to volumes "so that the project designer
can flexibly configure the ponding layer and storage layer to meet site constraints" (see
excerpt in Appendix A). This has been done on Latitude 33's plans. For instance, the
standard County bioretention basin design shows a 4-foot layer below the surface (1.5 feet of
growing medium and 2.5 feet of gravel). This depth can be increased above 4 feet by
increasing the gravel depth to meet the volume requirements in instances where the available
surface area is less than the area, A. The sum of the surface and subsurface storage volumes
must meet or exceed the volumes in Table 5. Furthermore, the surface area must be
maintained greater than the values in Table 5 to satisfy treatment control sizing.
10
5.0 STORM WATER BMP MAINTENANCE
The developer will be responsible for funding and implementing the operations and
maintenance of the project BMPs. Provisions will be made to transfer operations and
maintenance to the new owner in the event of a change in ownership. The homeowner's
association will ultimately be responsible for ongoing operations and maintenance. The
following describes the specific BMP maintenance.
Bioretention basins
The drainage outlet from the basins shall be inspected monthly and after large storm events.
Debris, sediment, and other obstructions shall be removed immediately from the outlet. The
habitat shall also be inspected annually and replanted as needed to maintain an adequate
cover.
Pervious Pavement
After installation, inspect pavement once a month for 4 to 6 months. After this period
inspection can occur annually, particularly after there has been heavy rain or storms, for this
is the time when the drainage voids can become clogged with organic debris. Sweep and/or
vacuum the permeable surface every 3 months. Street sweepers that have a vacuum and
brushes can be used. High pressure hosing shall be performed after sweeping/vacuuming.
Voids should be kept filled with aggregate.
Landscaping and Vegetated Swales
Maintenance will be performed by landscaping personnel. The vegetation will be maintained
and inspected on a monthly basis by landscape maintenance staff and will be replaced or
replanted, as necessary, to maintain a dense, healthy cover. The vegetation will also be
inspected after major storm events. Maintenance shall include periodic mowing, weed
control, irrigation, reseeding/replanting of bare areas, and clearing of debris. A design grass
height of 6 inches is recommended. Grass clippings shall not be left in grass swales. The
private drainage system will shall be kept clear of debris and inspect prior to and during the
rainy season to ensure it is free-flowing.
Efficient Irrigation
The landscaping personnel shall inspect and maintain the irrigation system on a regular basis.
This will occur during the routine maintenance activities. All valves, heads, shutoff devices,
lines, etc. shall be kept in a properly functioning condition. Any defective parts shall be
replaced immediately. The irrigation system shall be adjusted to prevent excessive runoff
from landscape areas. The irrigation schedule shall be adjusted based on seasonal needs.
Inlet Stenciling
Any stenciling shall be inspected at the beginning and end of each rainy season and repaired
or replaced, as needed.
Hazardous Wastes
Suspected hazardous wastes will be analyzed to determine disposal options. Hazardous
materials are not expected to be generated on-site; however, if discovered, hazardous
materials will be handled and disposed of according to local, state, and federal regulations. A
11
solid or liquid waste is considered a hazardous waste if it exceeds the criteria listed in the
California Code of Federal Regulations, Title 22, Article 11 (State of California, 1985).
6.0 SUMMARY/CONCLUSIONS
This final SWMP has been prepared in accordance with the City of Carlsbad's January 14,
2011, Standard Urban Storm Water Management Plan, and has evaluated and addressed
potential pollutants associated with the La Costa Residential project and its effects on water
quality. This SWMP has been based on the final engineering plans by Latitude 33. A
summary of the facts and findings associated with the project and the measures addressed by
this SWMP are as follows:
• The beneficial uses for the receiving waters have been identified. BMPs will be used
to protect the beneficial uses as outlined by the SUSMP.
• The project will not significantly alter drainage patterns and will meet
hydromodification requirements.
• A Storm Water Pollution Prevention Plan for construction activities has been
prepared to address construction-related water quality objectives.
• Permanent BMPs will be incorporated into the project design in the form of site
design, source control, and LID treatment control.
• Details for the treatment control bioretention BMPs are included after this text.
• The proposed BMPs address mitigation measures to protect water quality and
beneficial uses to the maximum extent practicable.
7.0 CERTIFICATION
The selection, sizing, and preliminary design of stormwater treatment and other control
measures in this plan meet the requirements of Regional Water Quality Control Board Order
R9-2007-0001 and subsequent amendments.
July 16,2013
Wayne W. Chang, RC^>6548 Date
12
^ CITY
CARLSBAD
O F
STORM WATER
STANDARDS
QUESTIONNAIRE
E-34
Development Services
Land Development Engineering
1635 Faraday Avenue
760-602-2750
www.carlsbadca.gov
INSTRUCTIONS:
To address post-development pollutants that may be generated from development projects, the City requires that new
development and significant redevelopment priority projects incorporate Permanent Storm Water Best Management
Practices (BMP's) into the project design per the City's Standard Urban Stormv\/ater Management Plan (SUSMP). To
view the SUSMP, refer to the Engineering Standards (Volume 4, Chapter 2) at www.carisbadca.qov/standards.
initially this questionnaire must be completed by the applicant in advance of submitting for a development application
(subdivision, discretionary permits and/or construction permits). The results of the questionnaire determine the level of
storm water standards that must be applied to a proposed development or redevelopment project. Depending on the
outcome, your project will either be subject to 'Standard Stormwater Requirements' or be subject to additional criteria
called 'Priority Development Project Requirements'. Many aspects of project site design are dependent upon the
storm water standards applied to a project.
Your responses to the questionnaire represent an initial assessment of the proposed project conditions and impacts.
City staff has responsibility for making the final assessment after submission of the development application. If staff
determines that the questionnaire was incorrectly filled out and is subject to more stringent storm water standards than
initially assessed by you, this will result in the return of the development application as incomplete. In this case, please
make the changes to the questionnaire and resubmit to the City.
If you are unsure about the meaning of a question or need help in determining how to respond to one or more of the
questions, please seek assistance from Land Development Engineering staff.
A separate completed and signed questionnaire must be submitted for each new development application submission.
Only one completed and signed questionnaire is required when multiple development applications for the same project
are submitted concurrently. In addition to this questionnaire, you must also complete, sign and submit a Project Threat
Assessment Form with construction permits for the project.
Please start by completing Section 1 and follow the instructions. When completed, sign the form at the end and submit
this with your application to the city.
SECTION 1 NEW DEVELOPMENT
Does your project meet one or more of the following criteria: YES NO
1. Housina subdivisions of 10 or more dwellina units. Examoles: sinale familv homes, multi-familv homes,
condominium and apartments X
2. Commercial - areaterthan 1-acre. Anv development other than heavy industry or residential. Examoles: hosoitals:
laboratories and other medical facilities; educational institutions; recreational facilities; municipal facilities; commercial
nurseries; multi-apartment buildings; car wash facilities; mini-malls and other business complexes; shopping malls;
hotels; office buildings; public warehouses; automotive dealerships; airfields; and other light industrial facilities.
X
3. Heavy Industrial / Industry- preater than 1 acre. Examples: manufacturinq plants, food processinq plants, metal
working facilities, printing plants, and fleet storage areas (bus, truck, etc). X
4. Automotive repair stioo. A facility categorized in any one of Standard Industrial Classification (SIC) codes 5013,
5014, 5541, 7532-7534, and 7536-7539 X
5. Restaurants. Any facility that sells prepared foods and drinks for consumption, includinq stationary lunch counters
and refreshment stands selling prepared foods and drinks for immediate consumption (SIC code 5812), where the
land area for development is greater than 5,000 square feet. Restaurants where land development is less than 5,000
square feet shall meet all SUSMP requirements except for structural treatment BMP and numeric sizing criteria
requirements and hydromodification requirements.
X
E-34 Page 1 of 3 REV 1/14/11
CITY
CARLSBAD
O F
STORM WATER
STANDARDS
QUESTIONNAIRE
E-34
Development Services
Land Development Engineering
1635 Faraday Avenue
760-602-2750
www,carlsbadca.gov
6. Hillside development Any development that creates more than 5,000 square feet of impervious surface and is
located in an area with known erosive soil conditions, where the development will grade on any natural slope that is
twenty-five percent (25%) or greater. X
7. Environmentally Sensitive Area (ESA)\ All development located within or directly adjacent^ to or discharqinq
directly"' to an ESA (where discharges from the development or redevelopment will enter receiving waters within the
ESA), which either creates 2,500 square feet or more of impervious surface on a proposed project site or increases
the area of imperviousness of a proposed project site 10% or more of its naturally occurring condition.
X
8. Parkina lot Area of 5,000 square feet or more, or with 15 or more parkino spaces, and potentially exposed to urban
runoff X
9. Streets, roads, hiqhways, and freeways. Any paved surface that is 5,000 square feet or qreater used for the
transportation of automobiles, trucks, motorcycles, and other vehicles X
10. Re(a// Gasoline Outlets. Servinq more than 100 vehicles per day and qreater than 5,000 square feet X
11. Coastal Development Zone. Any project located within 200 feet of the Pacific Ocean and (1) creates more than
2500 square feet of impervious surface or (2) increases impervious surface on property by more than 10%. X
12. More than 1-acre of disturbance. Project results in the disturbance of 1-acre or more of land and is considered a
Pollutant-generating Development Project'', X
1 Environmentally Sensitive Areas include but are not limited to all Clean Water Act Section 303(d) impaired water bodies; areas designated as Areas of Special
Biological Significance by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); water bodies
designated with the RARE beneficial use by the State Water Resources Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments);
areas designated as preserves or their equivalent under the Multi Species Conservation Program within the Cities and County of San Diego; and any other equivalent
environmentally sensitive areas which have been identified by the Copermittees.
2 "Directly adjacent" means situated within 200 feet of the Environmentally Sensitive Area.
3 "Discharging directly to" means outflow from a drainage conveyance system that is composed entirely of flows from the subject development or redevelopment site, and
not commingled with flow from adjacent lands.
4 Pollutant-generating Development Projects are those projects that generate pollutants at levels greater than background levels. In general, these include all projects
that contribute to an exceedance to an impaired water body or which create new impervious surfaces greater than 5000 square feet and/or introduce new landscaping
areas that require routine use of fertilizers and pesticides. In most cases linear pathway projects that are for infrequent vehicle use, such as emergency or maintenance
access, or for pedestrian or bicycle use, are not considered Pollutant-generating Development Projects if they are built with pervious surfaces or if they sheet flow to
surrounding pervious surfaces.
INSTRUCTIONS:
Section 1 Results:
If you answered YES to ANY of the questions above, your project is subject to Priority Development Project requirements. Skip Section 2 and
please proceed to Section 3. Check the "meets PRIORITY DEVELOPMENT PROJECT requirements" box in Section 3, Additional storm water
requirements will apply per the SUSMP.
If you answered NO to ALL of the questions above, then please proceed to Section 2 and follow the instructions.
E-34 Page 2 of 3
X
REV 1/14/11
CITY
CARLSBAD
O F
STORM WATER
STANDARDS
QUESTIONNAIRE
E-34
Development Services
Land Development Engineering
1635 Faraday Avenue
760-602-2750
www,carlsbadca,gov
SECTION 2 SIGNIFICANT REDEVELOPMENT
INSTRUCTIONS: Complete the questions below regarding your project YES NO
1. Project results in the disturbance of 1-acre or more of land and is considered a Pollutant-generating Development
Project *?
INSTRUCTIONS: If you answered NO, please proceed to question 2.
If you answered YES, then you ARE a significant redevelopment and you ARE subject to PRIORITY DEVELOPMENT PROJECT
requirements. Please check the "meets PRIORITY DEVELOPMENT PROJECT requirements" box in Section 3 below.
2. Is the project redeveloping an existing priority project type? (Priority projects are defined in Section 1)
INSTRUCTIONS: If you answered YES, please proceed to question 3.
If you answered NO, then you ARE NOT a significant redevelopment and your project is subject to STANDARD STORMWATER
REQUIREMENTS, Please check the "does not meet POP requirements" box in Section 3 below.
3. Is the work limited to trenching and resurfacing associated with utility work; resurfacing and reconfiguring surface
parking lots and existing roadways; new sidewalk; bike lane on existing road and/or routine maintenance of damaged
pavement such as pothole repair? Resurfacing/reconfiguring parking lots is where the work does not expose underlying soil
during construction.
INSTRUCTIONS: If you answered NO, then proceed to question 4,
If you answered YES, then you ARE NOT a significant redevelopment and your project is subject to STANDARD STORMWATER
REQUIREMENTS. Please check the "does not meet POP requirements" box in Section 3 below.
4. Will your redevelopment project create, replace, or add at least 5,000 square feet of impervious surfaces on existing
developed property or will your project be located within 200 feet of the Pacific Ocean and (1) create 2500 square feet or
more of impervious surface or (2) increases impervious surface on the property by more than 10%? Replacement of
existing impervious surfaces includes any activity that is not part of routine maintenance where impervious material(s) are
removed, exposing underlying soil during construction.
INSTRUCTIONS: If you answered YES, you ARE a significant redevelopment, and you ARE subject to PRIORITY DEVELOPMENT
PROJECT requirements. Please check the "meets PRIORITY DEVELOPMENT PROJECT requirements" box in Section 3 below. Review
SUSMP to find out if SUSMP requirements apply to your project envelope or the entire project site.
If you answered NO, then you ARE NOT a significant redevelopment and your project is subject to STANDARD STORMWATER
REQUIREMENTS, Please check the "does not meet PDP requirements" box in Section 3 below.
*for definition see Footnote 4 on page 2
SECTION 3 QUESTIONNAIRE RESULTS
My project meets PRIORITY DEVELOPMENT PROJECT (PDP) requirements and must comply with additional stormwater criteria
per the SUSMP and I understand I must prepare a Storm Water Management Plan for submittal at time of application. I understand
flow control (hydromodification) requirements may apply to my project. Refer to SUSMP for details.
• My project does not meet PDP requirements and must only comply with STANDARD STORMWATER REQUIREMENTS per the
SUSMP. As part of these requirements, I will incorporate low impact development strategies throughout my project.
Applicant Information and Signature Box This Box for City Use Oniy
Address: ^orth of Rancho Santa
Fe Road, West of Paseo Lupino
Assessor's Parcel Number(s):
223-050-68, 223-060-31
Applicant Name:
April Tornillo
Applicant Title:
Forward Planner
Applicant Signature: Date:
City Concurrence: YES NO
By:
Project ID:
E-34 Page 3 of 3 REV 1/14/11
LEGEND
PROPOSED STORM DRAIN
PROPOSED BIORETENTION BASIN
bl IL MAP
LA COSTA TOWN SQUARE
100
PER SHEET rj
FILTVI MATEFIi
4" PERF. PPC OUTLET PIPE DRAINS
TO aORETBITION OUTLET STRUCTURE H/
OKinCE FOR Flow CONTROL
r 1 \ !
a E u u 1 t EMSr. OiADE. ^4-rOOTHiaH
_ ( / CHAIN UNK FENCE
-t / ^tE-376.16
nr CLD/ATIOH PER-
PLAN
•PLANTING UEUIA
20 UIL HDPE UNER W/Z-INCH LA1ER OF SAND-
'A^SECTION 'A-A' BMP-5
nP. RETAINING HALL-
SEE SHEET IJ
<" PERF. PIPE, OUTLET PIPE DRAINS
TO eiORETOITION OUTLET STRUCTURE H/
ORIFICE FOR FLOW CONTRO. fitTEB UATERIAL-
20 UIL HDPE UNER W/2-INCH LAYER OF SAND-
SECTION 'E-E' BMP-3
SCALE: r = to'
4'FOOT HIGH
CHAIN UNK FENCE
4-FOOr HIGH
CHAIN UNK FENCE
SOILS REPORT
f PERF. PIPE. OUTLET PIPE DRAINS-
TV aORETENTION OUTLET STRUCTURE W/
ORinCE FOR FLOW CONTROL
20 UIL HDPE UNER W/2-INCH LAYER OF SAHD-
WS-3SI.0
4=F00T HICH CHAIN UNK FENCE
<" PERF PIPE. OUTLET PIPE DRAINS TO BIORETENTION OUTLET STRUCTURE W/
ORinCE FOR FLOW CONTROL
BASECTION 'B-B' BMP-1
20 UIL HDPE UNER W/2-INCH LAYER OF SAND-
FASECTION 'F-P BMP-4
SOIL MIX
SEE TREATUENT *
FLOW CONTROL BMPs
TABLE FOR REQUIRED
DEPTHS
GRAVEL
OUTFALL PIPE
/ (GENERAL NOTE I)
4' PERFORATED
PIPE
IMPERMEABLE
UNER
MOOS ««E Bttw 0Wl£3
i S2tO I
* HOI
FLOW ceKraot OR FiCE Pmre
BMP 2, 3, 4 OUTLET
Bioretention Facility Outlet Detail - A
REFERENCE ajy OF CARLSBAD SUSMP DATED JANUARY 14, 2011
OUTFALL PIPE
/ (GENERAL NOTE I)
IMPERMEABLE
LINER
PERFORATED PIPE
BIO-RETENTION TABLE
-:\\<\-
LOT 51
PAO-37B.a
RETAINING
SEE SHEET
<• PERF. PIPE, OUIIET PIPF DRAINS
TO BIORETENTION OUTLET STRUCTURE If/
osncE FOR aoif CONTROL
20 UIL HDPE UNER W/2-INCH LAYER OF SAND
C^SECTION 'C-C BMP-2
<• PERFORATED -
PIPE ORinCE' PER TABLE
BMP f mH. REQUIRED
SURFACE
AREA (SF)
PROVIDED
SURFACE
AREA (SF)
DI DEPTH
(INCHES)
VI
SURFACE
PONDING
AREA (CF)
02 DEPTH
(INCHES)
V2
STORAGE
LAYER
AREA (CF)
DETENTION
REQUIRED
(FEET)
D3 DEPTH
100 YEAR
DETENTION
(FEET)
D4 DEPTH
FREEBOARD
(FEET)
ORIFICE
SIZE
(INCHES)
1 St8 2,996 11,0 2,746 ;i 6.9-22.5) 19,7AVG 1.798 5,330 1.8 1.3 0.5
2 539 1.418 17,8 2,099 ;21.2-35.6) 23.4AVC 1.342 0.5
J 799 1,100 30,8 3.862 :44,7-66,3) 5I,9AV0 1.902 0.6
4 464 1,088 19,2 1,741 ;29,2-32,6) 30.9AV0 1.120 0,4
5 2,708 2,703 40,0 9.029 ;66.4-77.6) 72.0AVG 6.502 5,969 0.9 1,25 0,9
STORAGE" AND DRAINAGE LAYER PER CALTRANS SPEOFICATTON 68-2-02(F)
SCALE: I" = TO' BIORETENTION FACILITY OUTLET
BMP-1 DETAIL-B
BIORETENTION FACILITY OUTLET BMP
BMP-5 DETAIL-C
/ /// / \ // \ \\\\
vW^oW7777^(7/'-
D^SECTION 'D-D' '^^>^W
LATITUDE 3 3
PLANNING AND ENGINEERING
5355 MiRA BDRRENTO PLACE, SUITE 650
SAN DlEED. CA 9 2 12 1
TEL. 858.751 .0633
FAX. B5B.751.0634
0 5 10 20 40
SCALE: r = W DATE
REGISTRATION EXPIRES 6-30-2015 ENONEER OF WORK REVISION DESCRIPTION OTY APPROVAL
SHEET
6
AS BUILT"
REVIEHVED BY:
CITY OF CARLSBAD
ENGINEERING DEPARTMENT
SHEETS
13
ROUGH GRADING PLANS FOR
LA COSTA RESIDENTIAL
IPUp_l2-07_ CROSS SECTION SHFFT V12-D7
GLEN K. VAN PESKI
ENGllgEaNC MANAGER PE 41204 EXPIRES 3/31/15 DATE
OWN BY: _ CHKD BY; .
RVWD BY: .
PROJECT NO.
CT 12-05
DRAWING NO.
477-9A
H:\IIOO\IIX.I0\GP\TIX.IOCRADO6.ilw^ »/2l/20(J 4:1*56 PM
Insert
Map
Here
APPENDIX A
LOW IMPACT DEVELOPMENT
AND HYDROMODIFICATION ANALYSES
SUMMARY
The SUSMP requires that Drainage Management Areas (DMA) be delineated for various surface
types. DMAs were determined for roofs, asphalt (streets), concrete (sidewalks, driveways,
patios), pervious pavers, and landscaping. These are shown on the DMA Exhibit in this
appendix. The attached spreadsheet summarizes the DMAs to each of the bioretention basin
areas and provides the minimum bioretention surface area based on the bioretention + vault
sizing from the County of San Diego's BMP Sizing Calculator.
LOW IMPACT DEVELOPMENT AND HYDROMODIFICATION ANALYSIS WORKSHEET
(see exhibit for DMA delineations)
Bioretention Runoff Area x Runoff 4% Area,
Basin DMA1 Area, sf Area, ac Factor Factor, sf sf
BMP 1 Roofs 8,711 0,20 1.0 8,711
Asphalt 6,273 0,14 1.0 6,273
Concrete 3,268 0.08 1.0 3,268
Landscaping 21,947 0.50 0.1 2,195
Total 40,199 20,447 818
Bioretention Runoff Area x Runoff 4% Area,
Basin DMA 2 Area, sf Area, ac Factor Factor, sf sf
BMP 2 Roofs 6,323 0.15 1.0 6,323
Asphalt 3,754 0.09 1.0 3,754
Concrete 758 0.02 1.0 758
Landscaping 26,498 0.61 0.1 2,650
Total 26,751 13,485 539
Bioretention Runoff Area x Runoff 4% Area,
Basin DMAS Area, sf Area, ac Factor Factor, sf sf
BMP 3 Roofs 9,503 0.22 1.0 9,503
Asphalt 2,684 0.06 1.0 2,684
Concrete 4,522 0.10 1.0 4,522
Pervious Pavement 4,663 0.11 0.1 466
Landscaping 28,094 0.64 0.1 2,809
Total 49,466 19,985 799
Bioretention Runoff Area x Runoff 4% Area,
Basin DMA 4 Area, sf Area, ac Factor Factor, sf sf
BMP 4 Roofs 4,898 0.11 1.0 4,898
Asphalt 2,986 0.07 1.0 2,986
Concrete 1,643 0.04 1.0 1,643
Landscaping 20,701 0.48 0.1 2,070
Total 30,228 11,597 464
Pervious Runoff Area x Runoff 4% Area,
Paving DMAS Area, sf Area, ac Factor Factor, sf sf
BMP 5 Roofs 25,387 0.58 1.0 25,387
Asphalt 21,568 0.50 1.0 21,568
Concrete 16,175 0.37 1.0 16,175
Landscaping 45,700 1.05 0.1 4,570
Total 108,830 67,700 2,708
LEGEND
BMP DRAINAGE BASIN BOUNDARIES
ROOFS
ASPHALT PAVING (STREETS)
CONCRETE (SIDEWALKS, DRIVEWAYS, PATIOS)
LANDSCAPING
PERVIOUS PAVING
BIORETENTION BASIN
1" = 100'
ICQ
DRAINAGE MANAGEMENT AREAS
LA COSTA RESIDENTIAL
Soil Map—San Diego County Area, California
478000 478500
477900 478000 478700
A
Map Scale: 1:4,910 if printed on A size (8.5" x 11") sheet
250 500
Li^P'^ Natural Resources
Conservation Service
1,000 1,500
Web Soil Survey
National Cooperative Soil Survey 9/20/2012
Page 1 of 3
Project Summary
Project Name La Costa Residential
Project Applicant Latitude 33
Jurisdiction City of Cartsbad
Parcel (APN) 223-050-68, 223-060-31
Hydrologic Unit Carlsbad
Compliance Basin Summary
Basin Name: Local Drainage Basin
Receiving Water: Public Storm Drain System
Rainfall Basin Oceanside
Mean Annual Precipitation (Inches) 13.3
Project Basin Area (acres): 7.22
Waterstied Area (acres): 7,22
SCCWRP Lateral Channel Susceptiblity (H, M, L):
SCCWRP Vertlflcal Channel Susceptiblity (H, U, L):
Overall Channel Susceptibility (H, M, L): HIGH
Lower Flow/ Threshold (% of 2-Year Flow/): 0,1
Drainage Management Area Summary
ID Type BMP ID Description Area (ac) Pre-Project Cover Post Surface Type Drainage Soil Slope
28737 Drains to LID BMP 1 DMA 1 - Roofs 0.2 Pervious (Pre) Roofs Type D (high runoff - clay
sol,,. Flat - slope (less .,.
28739 Drains to LID BMP 1 DMA 1 - Concrete or Asphalt 0.22 Pervious (Pre) Concrete or asphalt Type D (high runoff - clay
sol,,. Flat - slope (less...
28740 Drains to LID BMP 1 DMA 1 - Landscaping 0.5 Pervious (Pre) Landscaping Type D (high runoff - clay
soi,,. Flat - slope (less...
28741 Drains to LID BMP 2 DMA 2 - Roofs 0,15 Pervious (Pre) Roofs Type D (high runoff - clay
sol.,. Flat - slope (less ...
28742 Drains to LID BMP 2 DMA 2 - Concrete or Asphalt 0.11 Pervious (Pre) Concrete or asphalt Type D (high mnoff - clay
soi... Flat - slope (less ...
28743 Drains to LID BMP 2 DMA 2 - Landscaping 0.61 Pervious (Pre) Landscaping Type D (high runoff - day
sol.,. Flat - slope (less ...
7/17/2013
28744 Drains to LID BMP 3 DMA 3 - Roofs 0.22 Pervious (Pre) Roofs Type D (high runoff - clay
sol,,. Flat - slope (less „,
28745 Drains to LID BMP 3 DMA 3 - Concrete or Asphalt 0.16 Pervious (Pre) Concrete or asphalt Type D (high runoff - clay
sol,.. Flat - slope (less „,
28746 Drains to LID BMP 3 DMA 3 - Pervious Pavement 0.11 Pervious (Pre) Pervious concrete or asphalt Type D (high runoff - clay
sol... Flat - slope (less „,
28747 Drains to LID BMPS DMA 3 - Landscaping 0.64 Pervious (Pre) Landscaping Type D (high runoff - clay
soi... Flat-slope (less „,
28748 Drains to LID BMP 4 DMA 4 - Roofs 0.11 Pervious (Pre) Roofs Type D (high runoff - clay
soi,,. Flat - slope (less „.
28749 Drains to LID BMP 4 DMA 4 - Concrete or Asphalt 0.11 Pervious (Pre) Concrete or asphalt Type D (high runoff - clay
soi... Flat - slope (less „,
28750 Drains to LID BMP 4 DMA 4 - Landscaping 0.48 Pervious (Pre) Landscaping Type D (high runoff - clay
soi... Flat - slope (less .,.
28751 Drains to LID BMPS DMA 5 - Roofs 0.58 Pervious (Pre) Roofs Type D (high runoff - clay
soi,,. Flat - slope (less „,
28752 Drains to LID BMPS DMA 5 - Concrete or Asphalt 0.87 Pervious (Pre) Conaete or asphalt Type D (high runoff - clay
sol,.. Flat - slope (less...
28753 Drains to LID BMP 5 DMA 5 - Landscaping 1,05 Pervious (Pre) Landscaping Type D (high runoff - clay
sol.,. Flat - slope (less ..,
LID Facility Summary
BMP ID Type Description Plan Area (sqft) Volume 1(cft) Volume 2(cft) Orifice Flow (cfs) Orifice Size (Inch)
BMP 1 Bioretention + Vault Bioretention Basin 1 818 4504 0.00 0.016 0.5
BMP 2 Bioretention + Vault Bioretention Basin 2 559 3076 0.00 0.015 0.5
BMP 3 Bioretention + Vault Bioretention Basin 3 792 4360 0.00 0.019 0.6
BMP 4 Bioretention + Vault Bioretention Basin 4 466 2568 0.00 0.012 0.4
BMP 5 Bioretention + Vault Bioretention Basin 5 2709 14902 0.00 0.043 0.9
7/17/2013