HomeMy WebLinkAboutCUP 12-08; Palomar Place Retail Center; Site Development Plan (SDP) (2)I
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STORM WATER MANAGEMENT PLAN
FOR
PALOMAR PLACE RETAIL CENTER
PALOMAR AIRPORT ROAD
CARLSBAD, CA 92011
Prepared F'or:
CLINT .FOWI.1ER
Lusardi Construction
1570 Linda Vista Dr.,
San Marcos CA 92078
Prepared By:
K&S Engineering, Inc.
7801 Mission Center Court, Suite 100
San Diego, CA 92108
Date
AUGUST 21, 2012
K&S Job No. 12-017
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TABLE OF CONTENTS
Section Page
1.0 INTRODUCTION 1
~~-~n-"-"'"'''"M' __ , ____ ,,, ··----'"'"'""''''"'-"'-•'-'"''-'''-'""-''''''' __ ,,,.,,_, _____ ,,, .. ~,-----·•-""-m'"""''-'"''''"-"""'"'"'' ______ ,,_.,,,,, __ ,,,,.,,,.,,,, .. ,,_,,,,,,-...--••••n•H•M•""'--'-''"-"'''''"-•••-
2.0 PROJECT DESCRIPTION 2
................................. -......... ~gu_!~_!_:: .. ~a!!_~_t.!__!\1~p_ ______ , _____ , ______ ................ ____ , _____ ,__________ ..................................................................... . ....................... _ .......................................... ---~ .. ..
3.0 HYDROLOGIC UNIT CONTRIBUTION 3 _____ ,,_,. ____ , __ ,,_, ____ ,_..., ............... , .... _,_, ___ , _______ , _____________ ,_,,,_ .. , .. ,.. . ............. ,. ....... ·······-·········-···· .................. ·········· ............................................. -...................... , ............... _ ........... ..
.................... -.............. _I.I!g_u,!_e 2 -~~~-~~«! .. ~~!er~h~~-~I.~!.~~-~~~--~1!!~ ... -..................... -.................. . ................................ -------......................................................... ~ ..
3.1 BENEFICIAL USE 4
Table 1 -Beneficial Uses 4 .......... ,,, __ ,,, ...... ~ .. -·---.. -~--·--------·-·------~-··----··-·----·-·····-·--·----·-· ... -·-·---·····~-·-..... ·-····-·····-···········-····"-~········--·· .. -·--····---------··-······---.. -"·--·-····-···-"·-"···--... ··--·-"·-·
4.0 CHARACTERIZATION OF PROJECT RUNOFF 5 ········-······-···-·-·-·"''''""""""_"____ , ____ ,___ --·-·-··-·-·· .................. -...................... _,,, .................................. ----··---··-.. -· .. ·-··--·-····--··"" _______ , _____ ,,,,,,, _______ _
_ , ...................................... -~~_!-~-=.._!'opogra~~c Vicinity Ma~------·-·-----·----·-·--------·--·--·---·········--·-----··--·----·----·-·----·---..................... ___ ....... -................................. §.. ... ..
4.1 POLLUTANTS OF CONCERN AND SOURCES 6
·······-··-·····----·---!_able_!_:: .. ~ntici~».~!_d ~d ~otenti~ .. ~~!!~~n~ .. Qe~~!:"~!~-~I.!-~ ... !Js~-!~_ .......................................... ~ .. ..
4.1.A GENERAL POLLUTANT CATEGORIES 6
4.2 SOIL CHARACTERISTICS 8
FIGURE 4 SOIL HYDROLOGIC GROUP MAP 8 ····-······ ............................... ·········---··-··-··-""'"'-''"'"----·-·-·----.. -····-·-··-·····-·"''"''"'"----... -·-··-········-··-·-·-·-··--··-····· .. -..... _,., ........ -............................................ ~---...................................... ,_, ........................ ____ ,, ·-· ""' ................. ,.., .. ,_ ... ..
4.3 SITE HYDROLOGY 9 ... -............................. _. ________ , ________ , __ .., ______________ ,,,_, ___ ,, ___ ,_,.~ .... --.... ---.. _,,._,, ______ ,,_, ____ ,, ............... -·--·-·--""' .... -......... _ .................................... _,_,................ ............... ........ .. ...................................................................................................... ..
?. .. :~ ....................... -~!!~~~TI~N ~~~~~.!~_!_~~~~!-.~~~ Q!!,~'.:_~!!. ....................... .. ........................................ ... . ........ _ .. !~--
5.1 ....... ~Q~_!~AC:! .. ~~~~~!_~~ ~!P..>. .. ~~~-~~_!_~~ .. !!~~~..................... ..................... ........................ ... 10
.... ~~!-.~ ...... ~:.l.!!Q~TY, _ _I_>.E~~..Q!~~-~~-QJ.~-~!-~~-!!~!~9.-~~~~~!~ .............................................. !~ .. .
5.2 SOURCE CONTROL BMPS 11 ............ ------------.... -.... _____ ,_ .. ___ .. , ____ ,,, ___________ ,, ...... ,_ ............... .......... .... . ......... ........... .. " ......................... ,,, __ , .. ,_, _____ ,_______ .................... _ ............................................. _ ......... ..
5.3 TREATMENT CONTROL BMPs 12 ............. ,,, __ , .................. -......................... _....,. ________ ..,_, ... ,_., __ ,,.. _________ ,. ____ ~ ... -... -..... _ .. ,.,_,,_,, ......... ____ ,_, _____ , ___ ,,_,,_~-------·""'" ................................................................................ ,_ ....... _ .......... _ .................................... _ .. ___ ,...,, .. _
TABLE 4 TREATMENT CONTROL BMP CATEGORIES 13
.............................. !~-~_!~-~---=--~!:.!.~!--~~~~-!~~~~~-!!~~!~ .. ~~~! .... ---··· ......................................... .. 14 .. .................................... -............ ,_ .... , ........................ _ .. __ _
5.5 SUMMARY 15
................ _ • .,, ............................. --·-·-------·-------.. --...... __ , ____________ ,,_._,,_,,., ......................... __ ,,, ___ , ........ 0«0 ............ ,_ ........................ ~ ........................... ._ ............................... _, ...... _,_,_,_, ......... ~ .... _,_ .. ,_.
6.0 STORMWATER BMP MAINTENANCE 16
6.1 MAINTENANCE MECHANISM 16
Table 5-Pennanent Treatment BMP Maintenance Schedule 17
..... --.................................. -------·----·-----·-·-···-·--------·"-"'"-""'"_'_"_""'" ______________ , ______ , .. ~-·--....... _,.,., ... _. ___ ,, __ .. _,,_, ....... « ... ___ ,_ .. __
7.0 FISCAL REsOURCES 18 ....... -................................ -.... ------· ____ , ___ , ___ ,_,,._,_, ______________ ,,_, _______ ,. ___ .......... __________ .. _______ , _______ , ______ ,,_,_, ______ ,_, __ ,, ___ ,,.,. .. _,
______________ .. _ .......... _ .. Table 6 Pe~~en!_!rea~~nt B~~ated_~~!_a~o~-~-~~~~a~ ~osts ........... ------.. -~~--
8.0 CONCLUSION 20
9.0 CERTIFICATION 21
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ATTACHMENTS ---·-----·----------··---·-·-·------·--·-·-·-----------···------··---·----·-·--·· A HYDROLOGY STUDY REFERENCE _, __ , _____ ,, __ ,, _____ ,, _____ ,_, ___ , __ ,, ____ .... _____ , __ ,,,_, ______ , ______ , ___ ,,, ........ -......... ..
B PERMANENT TREATMENT BMP INFORMATION
BIORE1ENTION FACILITIES
''''''''"" ... '"''-'''" __ ,,..,,_,, __ ,,_,.., ___ ,.,_., _____ •MnO-•Mo_..,.,_.,., ___ ,..,.,,,,..,,_.,_,_,..,,.,,..,,,,,,,,,~,..,,,,,,,,,,,,.,.,,..,.,,,,,..,,,,,,_,..,.,,,,,,.,,,,,,.,,,,,,,,.,,,,,,,,,.,,,.,,,,..,,m.,,,..,_,_,.,.,, .. , __ ,,_,..,,,,,,,,,,,.,,,.,, .. ,,,.,,,,,,,,,,,,,,,,,,,, .. ,,.,.,.,.,,,..,,_, __ ,,.,,,,.,,,.,,.,,,,,,,_,,,..,,,_,._.,,,,..,,,.,,,,,,,
C NUMERIC SIZING ..................................................... -.............. ____________ .,, __________ ,, ................. ---·-····--.. ·-···-·-·"'"""'"'''''' ............................................................................................. _ ........................... ~ ........... -........ -...................... -.... ~ ........................................... .
D CITY SUSMP FORMS
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1.0 INTRODUCTION
The California State Water Quality Control Board approved Order Number 2007-01 (Order) on January 24; 2007.The
Order outlines the stormwater discharge requirements for municipal stormwater systems, which drain "development"
areas from watersheds within;
1.) The County of San Diego,
2.) Incorporated cities of San Diego County, and
3.) San Diego Unified Port District.
The City of Carlsbad is one of the municipal co-permittees identified in the order and, therefore, subject to its
requirements.
In general, the order requires that Best Management Practices (BMPs):
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Control the post-development peak storm water storm discharge rates and velocities to maintain or reduce
pre-development downstream erosion
Minimize storm water pollutants of concern in urban runoff from new development through
implementation of source control BMPs
Remove pollutants of concern from urban runoff through implementation of structural treatment BMPs
Include proof of a mechanism, to be provided by the project proposal, which will ensure ongoing long-
term structural BMP maintenance. In addition, structural BMPs shall be located to infiltrate, filter, or treat
the required runoff volume or flow (numeric sizing criteria) prior to discharge to any receiving water body
supporting beneficial uses.
The "numeric sizing criteria" is either volume or flow based. Specifically, volume based BMPs must be designed
to infiltrate, filter, or treat the volume of runoff produced from a 24-hour -85th percentile storm event. This is
approximately 0.6 inches of runoff for San Diego County. Similarly, flow based BMPs must be designed to infiltrate,
filter or treat a flow rate of 0.2 inches of rainfall per hour. Note that the above "numeric sizing criteria" allows the
option of infiltration, filtering or treatment of this volume/flow and relates only to water quantity. Retention or
detention of water volume/flow is not a requirement of the "numeric sizing criteria."
This Water Quality Technical Report (WQTR) proposes to address the possible water quality impacts from the
proposed grading and private improvements of Palomar Place Retail Center. It will define the potential BMP options
that satisfy the requirements, identified in the following documents:
1.) City of Carlsbad SUSMP January 14, 2011.
2.) County of San Diego Municipal NPDES Storm Water Permit (Order Number 2007-01).
The goal of this WQTR is to develop and implement the best available procedure policies of the Standards to
insure to the maximum extent practicable that development does not increase pollutant loads from the project site and
considers urban run-off flow rates, potential pollutants, and velocities. The WQTR also intends to insure the
effectiveness of the Best Management Practices (BMPs) through proper maintenance that is based on long-term fiscal
planning.
This SWMP is subject to revisions by the engineer as needed due to site revisions or as directed by the City
Engineer.
According to the Storm Water Standards Questionnaire E-34 (see Appendix C of this report), the Project is subject
to;
• Priority Development Project (PDP)
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2.0 PROJECT DESCRIPTION
The Project is located on Assessors Parcel No. 211-040-34-00, which is Parcel 1 of Map No. 1017542 in the City Of
Carlsbad, County of San Diego, Figure 1 indicates the Project location.
The projects consist of renovation and expand an existing vacant building with a mixture of retail and restaurant uses as well
as add a mixed-use building; also, pedestrian access, landscaped areas and trash enclosure will be added; the parking lot
pavement will be restored and overlay.
The existing site contains driveway access, slope landscape irrigation, existing building and a paved parking lot. The Project
site has a total area of 1.75 acres, all existing site has been previously developed.
In general, the Project surface drains southwest to an existing storm drain system that underground directs the runoff to the
Canyon de las Encinas ultimately flowing to the Pacific Ocean. On site runoff will be treated with the two proposed bio-
retention BMP's to reduce or eliminate any pollutant generated by the project
FIGURE 1
SITE
LOCATION MAP
NTS
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3.0 HYDROLOGIC UNIT CONTRIBUTION
According to the State of California, Regional Water Quality Control Board, San Diego Hydrologic Basin
Planning Area, the Project is located in the Encinas hydrologic area (HA) 904.4 within the Carlsbad Watershed
hydrologic unit (HU). The sub-area is characterized by mostly urbanized commercial land. The cities of
Carlsbad, San Marcos, and Encinitas are located entirely within the HU while it also contains ±27 square miles
of the city of Escondido. Approximately 48% of the Carlsbad HU is urbanized. The dominant land uses are
residential (29%), commercial/industrial (6%), freeways/roads (12%), agriculture (12%), and
vacant/undeveloped (32%). Figure 2 indicates the Project general location within the HU.
FIGURE2
Carlsbad Watershed Hydrologic Unit
Approximate
Project
Location
Constituents of concern are; indicator bacteria, sedimentation/siltation, total dissolved solids, metals and
eutrophic indicators. The Agua Hedionda, Buena Vista, and San Elijo lagoons are experiencing impairments to
beneficial uses due to excessive coliform bacteria and sediment loading from upstream sources. San Elijo
Lagoon is also suffering from problems relating to eutrophication. These problems are largely a result of urban
run-off and sewage spills containing bacterial indicators. Poor tidal flushing of the lagoon is a primary cause of
problem eutrophic conditions. These coastal lagoons represent critical regional resources that provide freshwater
and estuarine habitats for numerous plant and animal species. Currently identification on the California 303(d)
list of other water bodies in the Carlsbad HU as impaired for elevated coliform bacteria, but none of them is
downstream of this Project.
The Project's 1.75 acres represents a very small percentage of the approximately 29,218 acres of the HSA and
an even smaller percentage of the HU. The existing site contains all impervious surface area. No increase is
proposed in the planned developed condition. Therefore there should be no negative impact of the project on the
hydrologic unit. Furthermore this project will introduce a Post Construction bio-retention BMP to treat any
pollutants generated on-site.
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The storm water drainage from this project discharges to Canyon de las Encinas which then discharges
ultimately to the Pacific Ocean. The project is located approximately 4,000 feet upstream from that point.
The project will not significantly alter the overall drainage pattern from the existing condition.
3.1 BENEFICIAL USE
The beneficial uses of inland surface water, coastal waters and groundwater for this hydrologic sub-area and
those downstream of the Project are identified in Table 1. There are no reservoirs or lakes that this project is
tributary to and located downstream. The data contained in this table is extracted from Project Clean Water.
TABLE 1
Beneficial water uses within the Carlsbad Watershed as designated in the State Water Resources Control Board's San Diego Region
Basin Plan
Beneficial Uses Inland Surface Water Coastal Waters Reservoirs and Lakes Ground Water
Municipal and Domestic Supply X X X
Agricultural Supply X X X
Industrial Service Supply X X X X
Navigation X
Contact Water Recreation X X X
Non·Contact Water Recreation X X X
Commercia l and Sport Fishing X
Wa rm Freshwater Habitat X X X
Cold Freshwater Habitat X X
Estuarine Habitat X
Wildlife Ha bitat X X X
Biological Habitats X
Rare, Threatened, or End. X X
Marine Habitat X
Migration of Aquatic Organisms X
Aquaculture X
Shellfish Harvesting X
Spawning, Reprod. and/or Early Develop. X
Hydropower Generation
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4.0 CHARACTERIZATION OF PROJECT RUN-OFF
According to the California 2006 303(d) list published by the San Diego Regional Water Quality Control
Board, the Canyon de la Encina (HSA 904.4) and Pacific Ocean shoreline does not have and impaired water
bodies. Figure 3 shows the approximate location of the Project and the surrounding topography.
FIGURE3
Topographic Vicinity Map
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4.1 POLLUTANTS OF CONCERN AND SOURCES
There are no sampling data available for the existing site condition. In addition, the project is not expected to
generate significant amounts of non-visible pollutants. However, the constituents listed in Table 2, which could
affect water quality, commonly generate from similar developments.
The nature of the project development can produce secondary pollutants of concern. Consider the pollutants
identified in Table 2 that aren't listed as pollutant stressors on the 303(d) List as being the secondary pollutants
of concern. Implementation of source and treatment controls during and after construction limits or eliminates
these pollutants to the maximum practicable extent.
The sources and affects of the primary and secondary pollutants of concern and other potential pollutants
occurring on the project are identified below Table 2.
TABLE2
Priority General Pollutant Categories
Project Heavy Organic Trash Oxygen Oil& Bacteria
Categories Sediments Nutrients Metals Compounds & Demanding Grease & Pesticides
Debris Substances Viruses
Commercial
Development pOl pOl X p(2l X p(Sl X p(3l p(Sl
> l 00,000 ft2
Parking Lots pOl pOl X X pOl X pOl
Restaurants X X X X pOl
X = anticipated
P = potential
( l) 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
Anticipated and Potential Pollutants Generated by Land Use Type
4.1.A General Pollutant Categories
The potential sources for the constituents of concern for the project could be, but are not limited to those
listed below:
o Sediments -Sediments are soils or other surficial materials eroded and then transported or deposited by
the action of wind, water, ice, or gravity. Sediments can increase turbidity, clog fish gills, reduce
spawning habitat, lower young aquatic organisms survival rates, smother bottom dwelling organisms,
and suppress aquatic vegetation growth.
o Nutrients -Nutrients are inorganic substances, such as nitrogen and phosphorus. They commonly exist
in the form of mineral salts that are either dissolved or suspended in water. Primary sources of nutrients
in urban run-off are fertilizers and eroded soils. Excessive discharge of nutrients to water bodies and
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streams can cause excessive aquatic algae and plant growth. Such excessive production, referred to as
cultural eutrophication, may lead to excessive decay of organic matter in the water body, loss of oxygen
in the water, release of toxins in sediment, and the eventual death of aquatic organisms.
o Metals -Metals are raw material components in non-metal products such as fuels, adhesives, paints,
and other coatings. Primary source of metal pollution in storm water are typically commercially
available metals and metal products. Metals of concern include cadmium, chromium, copper, lead,
mercury, and zinc. Lead and chromium have been used as corrosion inhibitors in primer coatings and
cooling tower systems. At low concentrations naturally occurring in soil, metals are not toxic. However,
at higher concentrations, certain metals can be toxic to aquatic life. Humans can be impacted from
contaminated groundwater resources, and bioaccumulation of metals in fish and shellfish.
Environmental concerns, regarding the potential for release of metals to the environment, have already
led to restricted metal usage in certain applications.
o Organic Compounds -Organic compounds are carbon-based. Commercially available or naturally
occurring organic compounds are found in pesticides, solvents, and hydrocarbons. Organic compounds
can, at certain concentrations, indirectly or directly constitute a hazard to life or health. When rinsing off
objects, toxic levels of solvents and cleaning compounds can be discharged to storm drains. Dirt, grease,
and grime retained in the cleaning fluid or rinse water may also adsorb levels of organic compounds that
are harmful or hazardous to aquatic life.
o Trash & Debris-Trash (such as paper, plastic, polystyrene packing foam, and aluminum materials)
and biodegradable organic matter (such as leaves, grass cuttings, and food waste) are general waste
products on the landscape. The presence of trash & debris may have a significant impact on the
recreational value of a water body and aquatic habitat. Excess organic matter can create a high
biochemical oxygen demand in a stream and thereby lower its water quality. Also, in areas where
stagnant water exists, the presence of excess organic matter can promote septic conditions resulting in
the growth of undesirable organisms and the release of odorous and hazardous compounds such as
hydrogen sulfide.
o Oxygen-Demanding Substances -This category includes biodegradable organic material as well as
chemicals that react with dissolved oxygen in water to form other compounds. Proteins, carbohydrates,
and fats are examples of biodegradable organic compounds. Compounds such as ammonia and
hydrogen sulfide are examples of oxygen-demanding compounds. The oxygen demand of a substance
can lead to depletion of dissolved oxygen in a water body and possibly the development of septic
conditions.
o Oil and Grease -Oil and grease are characterized as high-molecular weight organic compounds.
Primary sources of oil and grease are petroleum hydrocarbon products, motor products from leaking
vehicles, esters, oils, fats, waxes, and high molecular-weight fatty acids. Introduction of these pollutants
to the water bodies are very possible due to the wide uses and applications of some of these products in
municipal, residential, commercial, industrial, and construction areas. Elevated oil and grease content
can decrease the aesthetic value of the water body, as well as the water quality.
o Bacteria and Viruses -Bacteria and viruses are ubiquitous microorganisms that thrive under certain
environmental conditions. Their proliferation is typically caused by the transport of animal or human
fecal wastes from the watershed. Water, containing excessive bacteria and viruses can alter the aquatic
habitat and create a harmful environment for humans and aquatic life. Also, the decomposition of excess
organic waste causes increased growth of undesirable organisms in the water.
o Pesticides -Pesticides (including herbicides) are chemical compounds commonly used to control
nuisance growth or prevalence of organisms. Excessive application of a pesticide may result in run-off
containing toxic levels of its active component.
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4.2 SOIL CHARACTERISTICS.
Per the San Diego Hydrology Manual, Soil Hydrologic Groups map figure 4, the project area consists of soil
group B. Soil group B soils have moderate infiltration rates when thoroughly wetted. They consist chiefly of
soils that are moderately-deep to deep, moderately-well drained to well drained and moderately-coarse textured.
Rate of water transmission is moderate. Group B is classified as having a moderate infiltration rate. The USDA
Web Soil Survey corroborates this hydrologic soils group classification.
FIGURE 4
County of San Diego
Hydrology Manual
Soil Hydrologic Groups
8
Le end
Soil Groups
CJ GroupA
.. GroupB
CJ Groupe
Group D
CJ Undetermined
CJ Data Unavailable
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Based on the most recent San Diego County Hydrology Manual, the Project's runoff coefficient ('C' factor)
for the existing site value is C=0.95 and the value for the proposed site is C=0.95.
As the existing site is improved, there will be no increase in run-off in the developed condition due to the
previous impermeable surfaces.
The Project Hydrology Study contains detailed information as to the methodology used in obtaining these
results.
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5.0 MITIGATION MEASURES TO PROTECT WATER QUALITY
To address water quality for the project, BMP's will be implemented. As a Priority Project, these categories
require appropriate BMPs from the applicable categories below :
• Low Impact Develpment BMPs
• Source Control BMPs
• Treatment Control BMPs
In addition, incorporated into the Project are appropriate site design and source control BMPs for Standard
Projects.
5.1 LOW IMPACT DEVELOPMENT (LID) SITE DESIGN BMPS
Low Impact Development (LID) site design denotes a stormwater management and land development strategy
that emphasizes conservation and the use of on-site natural features integrated with engineered, small-scale
hydrologic controls that closely reflect pre-development hydrologic functions. Projects address SUSMP
objectives through the creation of a hydrologically functional project design that attempts to mimic the natural
hydrologic regime.
5.1.1 Priority Development Project LID BMP Requirements
Optimize Site Layout. The proposed site will have minimal grading and will utilize the existing topography.
The project site is previously developed, thereby negating the presence of natural areas. The site contains no
natural resources or areas for conserving. There are no existing trees of major consequence within the Project
site's disturbed footprint.
Minimize impervious Footprint. -Impervious areas are minimized through the consolidation of various uses
within each building structure and by increasing building density (3-story buildings); by having indoor parking,
and by implementing of shared driveways.
Disperse Runoff to adjacent Landscaping and IMP's. Where possible the project directs runoff from impervious
surfaces towards landscaped areas. These measures disconnect the paved surfaces and roof areas from direct
connection to MS-4.
Minimize Soil Compaction in Landscape Areas.-Soil Compaction is minimized whenever possible by:
a. The topsoil layer having a minimum depth of eight inches wherever designated planting areas occur.
b. Scarifying subsoils below the topsoil layer within landscaped areas by at least 4 inches. So layers do
not stratify, incorporate some of the upper material, if feasible.
Soil Amendments.-The Project's landscape Top Soil will be improved by implementing the following:
A topsoil layer shall have a minimum organic matter content of 10% dry weight in planting beds and 5%
organic matter content in turf areas. Maintain a soil pH from 6.0 to 8.0; planting beds mulched with two or more
inches of organic material; this improves water retention and infiltration while protecting the surface root zone
from extreme temperatures.
Convey Runoff safely from the tops of slopes.-The proposed project does not have existing, nor proposed
slopes.
Vegetated Disturbed soils with Native or drought tolerat vegetation.-Proposed landscaping consists of native or
drought tolerant species per landscape plans.
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5.2 SOURCE CONTROL BMPS
Source control BMPs, are selected, constructed, and maintained to comply with all applicable ordinances and
guidance documents. The proposed Development will have the following category requirements:
Specific Land Use Category BMPs
a) Use Efficient Irrigation Systems & Landscape Design.-Landscape irrigation systems shall be of an
efficient design with respect to each landscaped area's plantings specific water requirements.
Maintenance of system installations on a regular and timely basis prevents over-watering and the
transport of silts, sediments, fertilizers and pesticides into the storm drain system. Rain shut-off devices
or moisture sensors shall be integral to the operation of the irrigation system to avoid unnecessary
irrigation during wet weather conditions. Installing flow reducers or shut-off valves control loss of water
due to unexpected pressure drops or other type of system compromise. Pest resistant, drought tolerant or
native plants (per landscape architect plans) are used throughout the Project.
b) Design Trash Storage Areas to reduce Pollution Contribution.-Trash storage areas shall: be paved
with an impervious surface designed to prevent run-on from adjoining areas. Trash containers shall
contain attached lids to prevent rainfall intrusion, lids will remain closed when not in use.
c) Employ Integrated Pest Management Principles.-An integrated pest management (IPM) strategy is
an ecosystem based pollution prevention strategy that focuses on long-term prevention of pests or their
damage through a combination of techniques such as biological control, habitat manipulation,
modification of cultural practices, and use of resistant plant varieties. Use of pesticides occurs only after
monitoring indicates other IPM methods have failed. Pest control materials selected and applied in a
manner that minimize risks. Obtain more information on IPM principles from the UC Davis website
(http://www.ipm.ucdavis.edu/water/u/index.htrnl). If fertilizers and pesticides are necessary, they are
applied per manufacturer's minimum rates and guidelines to reduce the potential of pollutant
transporting to the environment and the risk to human health or beneficial non-target organisms. The
owner/developer/association will provide information on IPM practices, at the minimum relating to: the
prevention of pests intrusion to buildings and landscaping using barriers, screens, and caulking; physical
pest elimination techniques, such as, weeding, squashing, trapping, washing, or pruning out pests;
relying on natural enemies to eat insect pests and the proper use of pesticides as a last line of defense.
d) Provide Storm Water Conveyance System Stamping and Signage.-Any existing storm drain inlets affected by
the project drainage ( if not already signed), as well as all on-site private inlets, will be posted with signage,
stamped or stenciled (as appropriate to location) to provide notice against illegal dumping of pollutants with
prohibitive language or graphics to the satisfaction of the City Engineer. These warnings shall be maintained for
legibility throughout the development's existence. The owner will provide information to increase knowledge of
tenants/employs/future owners regarding impacts of pollutants and urban runoff on receiving waters.
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5.3 TREATMENT CONTROL BMPS
The primary pollutants of concern, TDS, bacteria, sediment, eutrophic conditions (nutrients) and metals are
considered pollutants that tend to associate with fine particles during treatment. Additionally, nutrients are
classified as pollutants that tend to be dissolved following treatment (per Table 3).
TABLE3
Pollutants That Tend Pollutants That Tend
Pollutant Coarse Sediment and to Associate with Fine to be Dissolved Trash Particles During Following Treatment Treatment
Sediment X X
Nutrients X X
Heavy Metals X
Organic Compounds X
Trash & Debris X
Oxygen Demanding X
Bacteria X
Oil & Grease X
Pesticides X
Table extracted from the City of Escondido Stormwater Management Requirements, January 14, 2011.
Description of Pollutants of Concern
Selected, treatment BMPs for this Project at this time is bioretention areas. The Post Construction BMP Site
Map exhibit, Figure 5, contains locations, details and contribution areas, attachment C shows the numeric sizing
for each basin of the project.
Per the selection matrix, Table 4, Bioretention facilities (LID) category offers a "High" treatment to the
primary pollutants.
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TABLE4
Treatment Control BMP Categories
Pollutants Settling Wet
Bioretention Basins Ponds Infiltration High-of Concern Facilities (Dry and Facilities or Media rate
(UD) Ponds) Wetlands Practices(UD)* Filters blofilters
Coarse
Sediment High High High High High High
and Trash
Pollutants
that tend to
associate
with fine High High High High High Medium
particles
during
treatment
Pollutants
that tend to
be Medium Low Medium High Low Low dissolved
following
treatment
Table extracted from the City of Carlsbad SUSMP, January 14, 2011.
Treatment Control BMP Selection Matrix
13
High-
rate Trash Racks •
media Hydrodynamic
filters Devices
High High
Medium High
Low Low
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6.0 STORMWATERBMP MAINTENANCE
The Project developer is financially responsible for the implementation of the erosion control measures during
the construction phase in addition to the construction/installation of the post-development BMPs. The developer
is responsible for the performance of the maintenance of the permanent BMPs. The applicant must ensure
implementation and maintenance of the BMPs through the maintenance mechanism identified below. This
mechanism must be acceptable to the City. The City Engineer will not consider structural BMPs "effective," and
therefore will not accept stormwater BMPs as meeting the MEP standard, unless a mechanism is in place that
will ensure ongoing long-term maintenance of all structural BMPs.
Most of the permanent BMPs accrue minimal maintenance costs. Mulching, seeding and plantings are part of
a continuing landscape maintenance program and can include the maintenance of the vegetated biofllter swale.
Rudimentary maintenance to the unit pavers consists of cleaning and maintaining the paver's bed. This can
occur as typical landscaping but may periodically require more intense maintenance. Landscaping maintenance
for permanent stabilization of graded areas and BMP maintenance will be the responsibility of the developer.
Development of an Operation & Maintenance (O&M) Plan for the Project BMPs is the responsibility of the
developer. The O&M Plan follows approval of this SWMP and prior to the issuance of any grading and/or
building permits. The O&M Plan identifies the party responsible for management of the storm water BMPs,
implementing a training program and duties, outlines maintenance frequency, routine service schedule, specific
maintenance activities, specific costs encountered with operation & maintenance and any other necessary
activities.
Table 5 (next page) provides an out1ine of the BMP maintenance necessary for the permanent treatment
BMPs.
6.1 MAINTENANCE MECHANISMS
Installation and maintenance of the post-development BMPs is the responsibility of the developer under a
Storm Water Maintenance Agreement (SWMA). A security will be required (of a form suitable to the City's
determination) to back-up the SWMA in an amount determined by the City Engineer based upon costs contained
in the O&M Plan. The SWMA remains in effect for the duration of the Project usage of the treatment BMPs
identified therein.
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TABLES
Permanent Treatment BMP Maintenance Program
A schedule of periodic maintenance should be implemented and modified, as needed, to insure effective operation of the indicated BMP's. As a guideline, a tentative schedule of maintenance frequency follows. The
schedule is based on certain indicators outlined for a particular BMP.
BMP ROUTINE ACTIONS MAINTENANCE FIELD MEASUREMENT FREQUENCY MAINTENANCE ACTIVITY INDICATORS
Height of vegetation. Average height of vegetation Visual inspection of vegetation. Inspect weekly and after Cut vegetation as required.
Bioretention Facility (grass) exceeds 4". rainy periods.
Assess adequate cover. Bare spots appear in Visual inspection of lack of Assess growth on a monthly Reseed vegetated areas as
planted/ mulched areas or less vegetative/mulch cover. Record basis. Assess mulch coverage required. No later than
than 70% coverage over entire locations to identify persistent on a monthly basis. November. Scarify area for
area. problem areas. reseeding. Reapply mulching as
required to cover bare spots.
Inspect for debris Debris or litter accumulation. Visual inspection for trash. During routine site Remove and properly dispose of
accumulation. landscape maintenance. trash, litter and debris.
Inspect for accumulation of Sediment is at or near vegetation Visual inspection for sediment Inspect monthly and after Remove accumulated sediment
sediment or erosion of soil. height. Rills or gullies in topsoil. depth. Visual inspection for rills each significant rainfall. when interfering with drainage
and soil erosion. flows.
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7.0 FISCAL RESOURCES
The owner/developer of the project will be fmancially responsible for the construction and installation of the
post-development BMPs and implementation of the LID site design and source control BMPs.
Installation and maintenance of the post-development BMPs will be the responsibility of the property owner
as designated in the Storm Water Maintenance Agreement and the O&M Plan. The permanent responsibility of
the post-development BMPs will remain with the owner or a designated association.
The following table outlines the anticipated maintenance costs of permanent treatment BMPs.
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TABLE6
PERMANENT TREATMENT BMP ESTIMATED OPERATION AND MAINTENANCE (0&M) COSTS
Permanent BMPs constructed and installed for this project will necessitate continuous operation and maintenance when the project is complete. O&M costs are based upon California Department of
Transportation estimated costs for pilot BMP project utilizing prevailing wage rates. Below are the itemized costs, based on prevailing wage rates, of the project BMPs as shown on the Site Map.
As identified in SWMP Section 7 .0, Fiscal Resources, the source for funding of BMP operation and maintenance is the responsibility of the property owner(s)/developer.
Post construction permanent BMP operation and maintenance costs include, but are not limited to the following:
LABOR EQUIPMENT MATERIALS
BMP OPI-'RAIION & MAINl F-NANCF-rl t:M 'IOIAl COSl
Per Hrs. Rate Cost I.yQ§, Days Rate Cost Item Cost
·1 rim[iJ&r, R(lke,
i ·1 on 1 ng:k, f-ork, ~hQY.eL ;;atety
BiOR[::"J cNTION f-ACI~II Y 12.0 .43Ji3 $523.56 llydroseeder 0.5 198.15 ;!l99.38 t:guipme_rli, l39iJS, $450 s·1,o13
.;;~ed, I.i3~Jing &
_Qi§QQE>?I
O&M TOTAL ~1 ,073
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8.0 CONCLUSION
This SWMP has shown LID site design, source control and treatment BMPs that should satisfy the
requirements identified in the Order and Standards. This report insures, to the maximum extent practicable, that
the development of the Project does not increase pollutant loads from the site.
The effectiveness of these BMPs depends upon the proper operation procedure and effective maintenance on
a definitive schedule identified within the O&M Plan. Long-term fiscal resources are necessary to provide the
appropriate operation and maintenance activities to prolong the effectiveness of the identified BMPs. The
developer is responsible for providing maintenance as outlined in the O&M Plan and agreed to in the SWFMA.
The provision of maintenance to BMPs is enforceable in accordance with the currently applicable City of
Carlsbad ordinances, policies and regulations.
It is shown that this project can meet the water quality objectives as outlined in Order R9-2007-01 with the
BMPs identified on the Site Plan. An analysis has been performed to ensure that the site can accommodate the
water quality BMPS. Therefore, it is anticipated that the downstream waters will not be affected by the
implementation of these BMPS.
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9.0 CERTIFICATION
By affixing my seal and signature to the front of this report, I, Kamal S. Sweis, certify the following:
This Storm Water Management Plan has been prepared in accordance with a system designed to assure that
qualified personnel properly gather and evaluate the information within.
To the best of my knowledge and belief, the information submitted is true, accurate, and complete.
Furthermore, the data upon which recommendations, conclusions and decisions are based were derived from
accepted engineering practices.
This Stormwater Management Plan has been prepared under my direction and supervision to comply with the
requirements of the City of Carlsbad "Storm Water Standards Manual," issued January 14, 2011 and the
SWRCB Order R9-2007-0l.
Kamal S. Sweis. P.E. 48592
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I ATTACHMENTS
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I ATTACHMENT A
I HYDROWGY STUDY REFERENCE
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------+---------+--------+--
--+---------+---------+----------1----+--
---1(--
[) STOP: UCHT STRE£T UGHT
TRAI'FoC SGOAl EASEIIEHT TO CITY OF------.!
CARlSBAD PER PW 16860 I
GRAPHIC SCALE
r1r1 L_l L_l
r1r1 L_l L_l
~ ~
L_l
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I
---
A.C. PA\DEHT 0\9l.AY
LEGEND
I. M.P.
BIORETENTlON FACIUTY (TREATMENT CONTROL)
SYMBOL
f:-:-:·:-:-:-:1
FEATURE
PAVEMENT AREA (CONC/ASPH)
SEEDED/LANDSCAPED AREA
ROOF
SURFACE FLOW (PROP -EXIST)
GRADE BREAK
TRASH ENCLOSURE AREA
ROOF DRAIN OUTLET
STORM DRAIN INLET
STORM DRAIN SIGNAGE
IF PLAN SIZE IS LESS THAN 24"x36".
THIS IS A REDUCED COPY. SCAlE PLAN ACCORDINGLY.
VARIES
POST-BliP IIIOR£1DI110N
BIORETENTJON (TYP)
NOT TO SCALE
-
SYMBOL
1 ~.-,tl I
BBBS&l
I I
TR
RD
0
[E)
A.C. PA~T O'.Ol.AY
·cuss 2 PEJni£AIIl.E"
CAllRAHS SPEC. 68-1.025
FIGURE 5
S\JSIIP P1011CT PIIOIIT\' PRIORITY PROJECT
fSHIT'il CITY OF CARlSBAD I SHEETS I L___j ENGINEERING DEPARlMENT
STORII li'ATER ILAIIAGI!IIENT PLAN FOR:
PALOMAR RETAIL CENTER
E K &5 ENGINEERING, INC.
Plami1g . Engileerng . Slrveyng
~
7801 IIDioo Centor Courf, s.ilo 100 S.. Diogo, CA 921011
(619} 296-5565 Fax: (619} 296-556"
PRO.£CT NO.
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5.5 SUMMARY
By implementing the LID site design BMPs, source control BMPs and treatment BMPs , the production of the
pollutants of concern will be limited.
An effective Integrated Pest Management program preventing access of animal pests to trash receptacles and
desirable environments limits the production of bacteria. Limited use of fertilizers and pesticides in landscaping
keeps the introduction of nutrients to a minimum. With adequately established ground plantings prevents soil
erosion there is a limited possibility for dissolved solids and sediments production from eroded soils. The
limited use of fertilizers and the soil stabilization of permanent plantings and mulches covering erodible soil
surfaces also limit the introduction of nutrient production leading to eutrophic conditions. Metals introduction to
storm water flows are only potentially present during the construction phase of the Project as the usage of the
materials most commonly containing this pollutant are most prevalent then.
All landscaped areas offer biofiltration for irrigation waters. Mulching, seeding and planting of these areas
provide bioftltration of any necessary pesticide and fertilizer applications. Following manufacturer guidelines to
avoid over-treatment of landscaping with pesticide & fertilizers wiii provide a limited occurrence of poilution
from these products in the planted areas of the Project.
The selected treatment BMPs in conjunction with the LID and source control BMPs provide limiting factors
in the production of the pollutants of concern. Moreover, the proper use and adequate maintenance of the bio-
retention areas, allow these effective treatment BMPs to work to their ultimate capabilities.
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HYDROLOGY/HYDRAULICS CALCULATIONS
FOR
PALOMAR PLACE RETAIL CENTER
PALOMAR AIRPORT ROAD
CARLSBAD, CA 92011
Prepared For:
CLINT FOWLER
Lusardi Construction
1570 Linda Vista Dr.,
San Marcos CA 92078
JN 12-017
August 28, 2012
48592
• ·' ~ ' • . '_.._ 1>
J-4--12
--~~~·-·-~~-~-.-· DATE
, ... ..
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TABLE OF CONTENTS
l.SITE DESCRIPTION
2.HYDROLOGY DESIGN MODELS
3.HYDROLOGIC CALCULATIONS APPENDIX A
4.TABLES AND CHARTS ................................ APPENDIX B
S.HYDROLOGY MAPS ................................... APPENDIX C
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1. SITE DESCRIPTION
THE PROJECT HAS BEEN PREVIOUSLY IMPROVED AND WE ARE NOT
ADDING MORE IMPERVIOUS AREA, THEREFORE THE EXISITNG AND
PROPOSED CONDITION WILL HAVE THE SAME "C" FACTOR OF 0.95.
THERE WILL BE NO INCREASE ON RUNOFF, THEREFORE NO IMPACT ON
THE DOWNSTREAM; FURTHERMORE WE WILL BE PROPOSING BIORETENTION
BASINS THAT WILL HELP INFILTRATE AND TREAT RUNOFF GENERATED
ON SITE.
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2. HYDROLOGY DESIGN MODELS
A. DESIGN METHODS
THE RATIONAL METHOD IS USED IN THIS HYDROLOGY STUDY; THE RATIONAL
FORMULA IS AS FOLLOWS:
Q CIA, WHERE : Q= PEAK DISCHARGE IN CUBIC FEET/SECOND *
C = RUNOFF COEFFICIENT (DIMENSIONLESS)
I = RAINFALL INTENSITY IN INCHES/HOUR (PER APPENDIX XI-A)
A = TRIBUTARY DRAINAGE AREA IN ACRES
*1 ACRE INCHES/HOUR = 1.008 CUBIC FEET/SEC
THE NATURAL WATERSHED METHOD IS ALSO USED IN THIS HYDROLOGY STUDY;
THE NATURAL WATERSHED FLOW FORMULA IS AS FOLLOWS:
B.
c.
Tc:=1. 8 (1.1,-C) (L) .s / [S (100)] ·333
L ""' OVERLAND TRAVEL DISTANCE 1N FBET
S SLOPE IN FT./FT.
Tc::: TIME IN MINUTES
DESIGN CRITERIA
-FREQUENCY, 100 YEAR STORM.
-LAND USE PER SPECIFIC PLAN.
-RAIN FALL INTENSITY PER COUNTY OF SAN DIEGO 2003 HYDROLOGY
DESIGN MANUAL.
REFERENCES
-COUNTY OF SAN DIEGO 2003, HYDROLOGY MANUAL.
-COUNTY OF SAN DIEGO 1992 REGIONAL STANDARD DRAWING.
-HAND BOOK OF HYDRAULICS BY BRATER & KING, SIXTH EDITION.
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APPENDIX A
(3. HYDROLOGIC CALCULATIONS)
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Project Name:
Project Location:
APN:
K & S Project No:
"C" FACTOR=
AREA BASIN 1 (AC) =
AREA BASIN 2 (AC) =
AREA BASIN 3 (AC) =
AREA BASIN 4 (AC) =
P6=
DURATION (D) MIN.=
INTENSITY (IN/HR) =
1=7.44 Pa D·o.s45
BASIN 1
BASIN 2
BASIN 3
BASIN 4
TOTALS
CONCEPTUAL HYDROLOGY
PALOMAR RETAIL CENTER
PALOMAR AIRPORT ROAD, CARLSBAD CA
211-040-34-00
12-017
0.95
0.48
0.35
0.54
0.67
2.5
10
4.21
O=CIA
Date:
c I A TOTAL RUNOFF (CFS)
0.95 4.21 0.48 1.92
0.95 4.21 0.35 1.40
0.95 4.2i 0.54 2.16
0.95 4.21 0.67 2.68
2.04 8.16
7/3/2012
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I APPENDIX B
(4. TABLES AND CHARTS)
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I -------0.0 "f'lil ""' 9.Q . -"' 1'. ; II lllln!IIIB
8.0 ~ " """ ~ :IIIITIIIHI
1.0 i'-" 1'. !'~"~ too
~" ".J"'~ ~ .... ' 6.0 . J ...... ~ .... ':... I .... ~~ s.o 1' N{ I I'" i'-~
~ .u,....
~ .... r = 3.2 inlhr
1
3.0 ... l"'ol
' .... I
~
t 1-
.... :
~ ~ !i.... i
.o I
: l .r i i ~ ~ "' ..... ! ' l I ~ I i i l i !
2
i T ! . I !~~ I I ; ; I I j ! .
' I I ~ ~ I ~' ' I I I ; ' I I ' i J ' : I . o I I . j i .9 ' I I I ~ ! .8 I
I i I ' t I. .7 .
! I I I ! l ' II . e I I .
I i i ~ I ; i I I I i l . 5 • I i
T i I i 1 i I . I l I i l ; I } ; l j I I I 4-I
I I I f lT Ill ! I i
; I
! ! , l 1 I I 3 I • ' >
0
0
0.
0.
I
0.2
' I
' --1 ·r tc=20m
I I I
i : I I HI II II I
5 6 7 8 9 10
0.1 40 50 15 20 30
Minutes Duratio
-----,
I I! . • i i ·Ill i I I i J I I
l l \ ill I ; I I i II i
i l'l: '. I ! I II il i
EQUATION ji
7_44 P6 0-0.645 I~ I =
! = Intensity {ln/hn ~~ Ps = 8-Hour Precipitation (In }
D = Duration (min) 'I l
i ! i: I . , ·r li l I ! i ! I
t I i ) TIT I 'l I ' I II ! I i I l I I
~ ' : i I ~ I ! I l I
; ! ; I I i; I !
j
I
~ ~fll I II' I
Ill ; ! I I !
!"~~ ~-~ ..L . I ll
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""" ~8:f ~~ !j
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~· . j ~ J I .
l .. -I 6. N il-,.. i l" j I 5.
I ;; ~~ I 1'1-J. .I ·l I 5.
I IN..' 11-i..L ! :X l l i 4.
II' "l· ;-,..; H-11· i iii 4. it . I i
I ~ Ji ~ n I 3. , .... I 'I I 3.
j I l'i I I ! i f i Iii i
'I • !'1. I 1: I ! 2.
0
5
~ i i I N I
'"
I j '' ~ 'I 'I
i' ! f 1 2.
I i 0
i .
' : 1. 5
~t-t~
i I
i 1 . I . • I
i +
1.0
I
; IJ_ i +--i-.J·. I -+ ' l '' i I
I, I . 1i l I
! . l ; . i .~1!1 1 1.!.!.1
~ 3 4 5 6
Moun:;
lntensfty .. Ouratlon Design Chari= Example
-------Direction• for Application:
(1) From ptecipitation maps determine 6 hr and 24 hr amounts
· for the selected frequency. These maps are included in the
County Hydrology Manual (10, 50, and 100 yr maps Included
in the Design and Procedure Manual} •
(2) Adjust 6 hr precipitation (if necessary) so that it is within
the range of 45% to 65% of the 24 hr precipitation (not
applicaple to Desert).
(3) Plot 6 hr precipitation on the right side of the chart.
(4) Draw a line through the point parallel to the plotted lines .
(5) l'h!s line is the intensity-duration curve for the location
betng analyzed.
Appllcatlon Form:
(a) Selected frequency lQ_ year
(b) p~ =~~·_in., p24 = __ t>_ ,.:9.pp = 54 35 %(2) 24 --
(c) Adjusted p6(2l = __ ·n.
(d) tx = _10_ min.
(e) I = _±L in./hr.
Note: This Chart replaces the Intensity-Duration-Frequency
curves used since 1965 . ·
FIG -URI
' I Ill -
-'
I; p
l I I
l! i
! I
i_l
I' ; .. •••.: j-.l!i i. !
I.
I'
1!
-H rH
-----
IiI .i_U I I .. JTL .~-~~-t :
:--... ;._:,_ L: ..
-----
·-~-· I
.. •.o,. '"" !~:
---
~-~ ' I. II I ·;-
Rafr!fall Isopluvials
100 Year Rainfall Event-6 Hours
lsopluvial (inches)
. •"•t ..: i-"'1
·~ ii\ "'
\'\;:;,.. H .... S:rn D .... ·gn C."M.:I~
-
~ ;
!·I\·
i i ):J I t l!
I-I l II! I I I I
I! 1.
I
---
I
~;J j·l
J
- -
I
:I
! i
l
-
J . g-··
'·-· I ~~~I :
-- - -- - -
I I
- ----
! •, ..
I
'·
County of San Diego
Hydrology Manual
Rai71fctll isopluvials
100 Year Rainfall Event-24 Hours
lsopluvlal {Inches)
"1: N--'GIS ~~~~· " ... ,..i;, ! .. ., ~ • ·11, \\; .~ H:1.~.: S>ln Dicg_o C'.r~,~.-· .. 11
~~~=~WNWJflYa=Nit)ll«l,B'llQii)(PJ£SS '-.:·~· ~;-:~;:~::,=-~., T -·: ... ~-~..:;\·.· -...
' Miles
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I APPENDIX C
I (5. HYDROLOGY MAP)
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T .-r ••
----....... ______ ....... ---
, I ~
GRAPHIC SCAU:
I I I T
VICINITY ._.AP
EIOIE IEMJON CTYP>
Ifill K &S ENGINEERING, INC
~ Plalmg E~ &neyr,g
7801 llission c;...,. COII/t, Suitt 100 Son Diogo, CA 921011
(619) 296 ·5565 rax. (619) 296-5564
IIIT10~
~~c~~gm1~
~---I ; PAIDIW! RIT.!IL Cllftllll
10==11 PROET~ 11<:~1
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ATTACHMENT B
PERMANENT TREATMENT BMP INFORMATION
Bioretention Facilities
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Bioretention
Description
The bioretention best management practice (BMP) functions as a
soil and plant-based filtration device that removes pollutants
through a variety of physical, biological, and chemical treatment
processes. These facilities normally consist of a grass buffer
stJ:ip, sand bed, ponding area, organic layer or mulch layer,
planting soil, and plants. The runoffs elocity is reduced by
passing over or tlu-ough buffer strip and subsequently distributed
evenly along a ponding area. £>..'"filtration of the stored water in
the bioretention area planting soil into the underlying soils
occur over a pe1iod of day .
California Experience
None documented. Bioretention has been used as a stormwater
BMP since 1992. In addition to Prince G orge's County, MD and
Alexandria, VA, bioretention has been used successfully at urban
and suburban areas in Montgomery County, MD~ Baltimore
County, MD; Chesterfield County, VA~ Prince William County,
A; Smith Mountain Lake State Park, VA; and ary, C.
Advantages
• Bioretention provides stormwater treatment that enhances
the quality of downstream water bodies by temporarily
storing runoff in the BMP and releasing it over a period of
four days to the receiving water (EPA, 1999).
• The vegetation provides shade and wind breaks, absorbs
noise, and improves an area's landscape.
limitations
• The bioretention BMP is not recommended for areas with
slopes greater than 20% or where mature tree removal would
January 2003 California Stormwater BMP Handbook
New Development and Redevelopment
www.cabmphandbooks.com
TC-32
Design Considerations
• Soil for Infiltration
• Tributary Area
• Slope
• Aesthe~cs
• Environmental Side-effects
Targeted Constituents
0 Sediment • 0 Nutrients A
0 Trash • 0 r.1etals • 0 Baeten a •
0 Oil and Grease •
0 Orgamcs •
Legend (Removal Effectiveness)
• Low • H~gh
A Med1um
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TC-32 Bioretention
be required since clogging may result, particularly if the BMP receives runoff with high
sediment loads (EPA, 1999).
• Bioretention is not a suitable BMP at locations where the water table is v .. ithin 6 feet of the
ground surface and where the surrounding soil stratum is unstable.
• By design, bioretention BMPs have the potential to create very attractive habitats for
mosquitoes and other vectors because of highly organic, often heavily vegetated areas mixed
with shallow water.
• In cold climates the soil may freeze, preventing runoff from inftltrating into the planting soil.
Design and Sizing Guidelines
• TI1e bioretention area should be sized to capture the design stonn rm1off.
• In areas where the native soil permeability is less than 0.5 in/hr an underdrain should be
provided.
• Recommended minimum dimensions are 15 feet by 40 feet, although the preferred ,.-.,'idth is
25 feet. Excavated depth should be 4 feet.
• Area should drain completely \Vithin 72 hours.
• Approximately 1 tree or shrub per 50 ft2 ofbioretention area should be included.
• Cover area \\cith about 3 inches of mulch.
Constructionjlnspection Considerations
Bioretention area should not be established until contributing watershed is stabilized.
Performance
Bioretention removes stonuwater pollutants through physical and biologic.al processes,
including adsorption, filtration, plant uptake, microbial activity, decomposition, sedimentation
and volatilization (EPA, 1999). Adsorption is the process whereby particulate pollutants attach
to soil (e.g., clay) or vegetation surfaces. Adequate contact time between the surface and
pollutant must be provided for in the design of the system for this removal process to occur.
Tims, the infiltration rate of the soils must not exceed those specified in the design criteria or
pollutant removal may decre.ase. Pollutants removed by adsorption include metals, phosphorus,
and hydrocarbons. Filtration occurs as rm1off passes through the bioretention area media, such
as the sand bed, ground cover, and planting soil.
Common particulates removed from stonnwater include particulate organic matter,
phosphorus, and suspended solids. Biological processes that oc.eur in wetlands result in
pollutant uptake by plants and mieroorganisms in the soil. Plant growth is sustained by the
uptake of nutrients from the soils, vvith woody plants locking up these nutrients through the
seasons. Microbial activity \\rithin the soil also contributes to the removal of nitrogen and
organic matter. Nitrogen is removed by nitrifying and denitrifying bacteria, while aerobic
bacteria are responsible for the decomposition of the organic matter. Microbial proce.sses
require ox-ygen and c.an result in depleted ox-ygen levels if tl1e bioretention area is not adequately
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Bioretention TC-32
aerated. Sedimentation occurs in the swale or ponding area as the velocity slows and solids fall
out of suspension.
TI1e removal effectiveness ofbioretention has been studied during field and laboratory studies
conducted by the University of Maryland (Davis et al, 1998). During these experiments,
synthetic stormwater runoff was pumped through several laboratory and field bioretention areas
to simulate typical storm events in Prince George's County, MD. Removal rates for heavy metals
and nutrients are shown in Table 1.
Table 1 Laboratory and Estimated
Bioretention Davis et al. (1998};
PGDER {1993}
Pollutant Removal Rate
Total Phosphorus 70-83%
Metals (Cu. Zn. Pb) 93-98%
TKN 68-8o%
Total Suspended Solids 90%
--
Organics 90%
Bacteria 90%
Results for both the laboratory and field experiments were similar for each of the po1lutants
analyzed. Doubling or halving the influent pollutant levels had little effect on the effluent
pollutants concentrations (Davis et al, 1998).
TI1e microbial activity and plant uptake occurring in the bioretention area \villlikely result in
higher removal rates than those determined for infiltration BMPs.
Siting Criteria
Bioretention BMPs are generally used to tre.at storm water from impervious surfaces at
commercial, residential, and industrial are.as (EPA, 1999). Implementation ofbioretention for
stormwater management is ideal for median strips, parking lot islands, and swales. Moreover,
the runoff in these areas can be designed to either divert directly into tl1e bioretention area or
convey into the bioretention area by a curb and gutter collection system.
TI1e best location for bioretention areas is upland from inlets tl1at receive sheet flow from graded
areas and at areas that '"'ill be excavated (EPA, 1999). In order to maximize treatment
effectiveness, the site must be graded in such a way that minimizes erosive conditions as sheet
flow is conveyed to the treatment area. Locations where a bioretention area c.an be readily
incorporated into the site plan without further environmental damage are preferred.
Furthermore, to effectively minimize sediment loading in the treatment area, bioretention only
should be used in stabilized drainage areas.
January 2003 California Stormwater BMP Handbook
New Development and Redevelopment
www .cabmphandbooks.com
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TC-32 Bioretention
Additional Design Guidelines
TI1e layout of the bioretention area is determined after site constraints such as location of
utilities, underlying soils, existing vegetation, and drainage are considered (EPA, 1999). Sites
with loamy sand soils are especially appropriate for bioretention because the excavated soil ean
be backfilled and used as the planting soil, thus eliminating the eost of importing planting soil.
Tite use of bioretention may not be feasible given an unstable smTotmding soil stratmn, soils
with day content greater than 25 percent, a site \\ith slopes greater than 20 percent, andjor a
site with mature trees that would be removed during construction of the BMP.
Bioretention can be designed to be off-line or on-line of the existing drainage system (EPA,
1999). TI1e drainage area for a bioretention area should be benveen 0.1 and 0-4 hectares (0.25
and 1.0 acres). Larger drainage areas may require multiple bioretention areas. Furtbennore,
the maximum drainage area for a bioretention area is determined by the expected rainfall
intensity and runoff rate. Stabilized areas may erode when velocities are greater than 5 feet per
second (1.5 meter per second). Tite designer should detennine the potential for erosive
conditions at the site.
TI1e size of the bioretention area, which is a function of the drainage area and the runoff
generated from the area is sized to capture the water quality volume.
Tite recommended minimum dimensions of the bioretention area are 15 feet (4.6 meters) \vide
by 40 feet (12.2 meters) long, where the minimum lvidth allows enough space for a dense,
randomly-distributed area of trees and shrubs to become established. Thus replicating a natural
forest and creating a microclimate, thereby enabling the bioretention area to tolerate the effects
of heat stress, acid rain, nmoff pollutants, and insect and disease infestations which landscaped
areas in urban settings t)''}>ically are unable to tolerate. The preferred \Vidth is 25 feet (7-6
meters), \'l>ith a length of hvice the \vidth. Essentially, any facilities \\ider than 20 feet (6.1
meters) should be h\ice as long as they are wide, which promotes the distribution of flm.,r and
decreases the chances of concentrated flow.
In order to provide adequate storage and prevent water from standing for excessive periods of
time the ponding depth of the bioretention area should not exceed 6 inches ( 15 centimeters).
Water should not be left to stand for more than 72 hours. A restriction on the type of plants that
can be used may be necessary due to some plants' water intolerance. Furthermore, if water is
left standing for longer than 72 hours mosquitoes and other insects may start to breed.
TI1e appropriate planting soil should be backfilled into the excavated bioretention area. Planting
soils should be sandy loam, loamy sand, or loam texture \\rith a clay content ranging from 10 to
25 percent.
Generally the soil should have infiltration rates greater than 0.5 inches (1.25 centimeters) per
hour, which is typical of sandy loams, loamy sands, or loams. TI1e pH of the soil should range
benveen 5-5 and 6.5, where pollutants such as organic nitrogen and phosphorus can be adsorbed
by the soil and microbial activity can flourish. Additional requirements for the planting soil
include a 1.5 to 3 percent organic content and a maximum 500 ppm concentration of soluble
salts.
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Bioretention TC-32
Soil tests should be performed for every 500 cubic yards (382 cubic meters) of planting soil,
vvith the exception of pH and organic content tests, which are required only once per
bioretention area (EPA, 1999). Planting soil should be 4 inches (10.1 centimeters) deeper than
the bottom of the largest root ball and 4 feet ( 1.2 meters) altogether. This depth vvill provide
adequate soil for the plants' root systems to become established, prevent plant damage due to
severe \\ind, and provide adequate moisture capacity. Most sites vvill require excavation in
order to obtain the recommended depth.
Planting soil depths of greater than4 feet (1.2 meters) may require additional construction
practices such as shoring measures (EPA, 1999). Planting soil should be placed in 18 inches or
greater lifts and lightly compacted until the desired depth is reached. Since high canopy trees
may be destroyed during maintenance the bioretention area should be vegetated to resemble a
terrestrial forest community ecosystem that is dominated by understory trees. Three species
each of both trees and shrubs are recommended to be planted at a rate of 2500 trees and shrubs
per hectare (1000 per acre). For instance, a 15 foot (4.6meter) by 40 foot (12.2 meter)
bioretention area (6oo square feet or 55-75 square meters) would require 14 trees and shrubs.
The shrub-to-tree ratio should be 2:1 to 3:1.
Trees and shrubs should be planted when conditions are favorable. Vegetation should be
watered at the end of each day for fourteen days follovving its planting. Plant species tolerant of
pollutant loads and varying wet and dry conditions should be used in the bioretention area.
The designer should assess aesthetics, site layout, and maintenance requirements when
selecting plant species. Adjacent non-native invasive species should be identified and the
designer should take measures, such as providing a soil breach to eliminate the threat of these
species invading the bioretention area. Regional landscaping manuals should be consulted to
ensure that the planting of the bioretention area meets the landscaping requirements
established by the local authmities. The designers should evaluate the best placement of
vegetation within the bioretention area. Plants should be placed at irregular intervals to
replicate a natural forest. Trees should be placed on the perimeter of the are.a to provide shade
and shelter from the wind. Trees and shmbs can be sheltered from damaging flows if they are
placed away from the path of the incoming runoff. In cold climates, species that are more
tolerant to cold winds, such as evergreens, should be placed in '"'indier areas of the site.
Following placement of the trees and shmbs, the ground cover and/ or mulch should be
established. Ground cover such as grasses or legumes c.an be planted at the beginning of the
growing season. Mulch should be placed immediately after trees and shrubs are planted. Two
to 3 inches (5 to 7.6 em) of commercially-available fine shredded hardwood mulch or shredded
hardwood chips should be applied to the bioretention are.a to protect from erosion.
Maintenance
TI1e primary maintenance requirement for bioretention areas is that of inspection and repair or
replacement of the treatment area's components. Generally, this involves nothing more than the
routine periodic maintenance tl1at is required of any landscaped area. Plants that are
appropriate for the site, climatic, and watering conditions should be selected for use in the
bioretention cell. Appropriately selected plants \\'ill aide in reducing fertilizer, pesticide, '\\-'Rter,
and overall maintenance requirements. Bioretention system components should blend over
time through plant and root growth, organic decomposition, and the development of a natural
January 2003 California Stormwater BMP Handbook
New Development and Redevelopment
www .cabmphandbooks.com
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TC-32 Bioretention
soil horizon. TI1ese biologic and physical processes over time will lengthen the facility's life span
and reduce the need for ex1:ensive maintenance.
Routine maintenance should include a biannual health evaluation of the trees and shrubs and
subsequent removal of any dead or diseased vegetation (EPA, 1999 ). Diseased vegetation
should be treated as needed using preventative and low-toxic measures to the extent possible.
BMPs have the potential to create very atu·active habitats for mosquitoes and other vectors
because of highly organic, often heav-ily vegetated areas mLxed \Vith shallow water. Routine
inspections for areas of standing water within the BMP and cmTective measure.s to restore
proper infiltration rates are necessary to prevent cre,ating mosquito and otl1er vector habitat. In
addition, bioretention BMPs are susceptible to invasion by aggre.ssive plant species such as
cattails, which increase the chances of water standing and subsequent vector production if not
routinely maintained.
In order to maintain the treatment area's appearance it may be necessary to prune and weed.
Furthennore, mulch replacement is suggested when erosion is evident or when the site begins to
look unattractive. Specific.ally, the entire are.a may require mulch replacement every two to
three years, although spot mulching may be sufficient when there are random void areas. Mulch
replacement should be done prior to the start of the wet season.
New .Jersey's Departiuent of Environmental Protection states in their bioretention systems
standards that aecumulated sediment and debris removal (especially at the inflow point) will
normally be the primary maintenance funetion. Other potential tasks include replacement of
dead vegetation, soil pH regulation, erosion repair at inflow points, mulch replenishment,
unclogging the underdrain, and repairing overflow structures. There is also the possibility that
the cation exchange capacity of the soils in the cell \Vil1 be significantly redueed over time.
Depending on pollutant loads, soils may need to be replaced within 5-10 years of construction
(LID, 2000).
Cost
Construction C.ost
Construction cost e.stimates for a bioretention area are slightly greater than those for the
required landsc.aping for a new development (EPA, 1999 ). A general rule of thumb (Coffman,
1999) is that residential bioretention areas average about $3 to $4 per square foot, depending on
soil conditions and the density and types of plants used. Commercial, industrial and
institutional site costs can range benveen $10 to $40 per square foot, based on the need for
control structures, curbing, storm drains and underdrains.
Retrofitting a site typically costs more, averaging $6,soo per bioretention area. l11e higher costs
are attributed to the demolition of existing concrete, asphalt, and existing structures and the
replacement of flll material with planting soil. l11e costs of retrofitting a commercial site in
Maryland, Kettering Development, with 15 bioretention are,as were estimated at $111,600.
In any bioretention are,a design, the cost of plants varies substantially and c.an account for a
significant portion of the expenditures. While the.se cost estimates are slightly greater than
those of typic,allandsc.aping treatment (due to tlle incre,ased number of plantings, additional soil
excavation, backfill material, use of underdrains etc.), those landscaping expenses that would be
required regardless of the bioretention installation should be subtracted when detennining the
net cost.
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Bioretention TC-32
Perhaps of most importance, however, the cost savings compared to the use of traditional
structural stonuwater conveyance systems makes bioretention areas quite attractive financially.
For example, the use ofbioretention can decrease the cost required for constructing stonuwater
conveyance systems at a site. A medical office building in Maryland was able to reduce the
amount of stonn drain pipe that was needed from 8oo to 230 feet-a cost savings of $24,000
(PGDER, 1993). And a new residential dE'velopment spent a total of approximately $10o,ooo
using bioretention cells on each lot instead of nearly $400,000 for the traditional stonmvater
ponds that were originally planned (Rappahanock, ). Also, in residential areas, stonnwater
management controls become a part of each property owner's landscape, reducing the public
burden to maintain large centralized facilities.
Maintenance C,ost
TI1e operation and maintenance costs for a bioretention facility \'v'ill be comparable to those of
typical landscaping required for a site. Costs beyond the nonnallandscaping fees will include
the cost for testing the soils and may include costs for a sand bed and planting soil.
References and Sources of Additional Information
Coffman, L.S., R. Goo and R. Frederick, 1999: Low impact development: an innovative
alternative approach to stonnwater management. Proceedings of the 26th Annual Water
Resources Planning and Management Conference ASCE, .June 6-9, Tempe, Arizona.
Davis, A.P., Shokouhian, M., Sharma, H. and Minami, C., "Laboratory Study of Biological
Retention (Bioretention) for Urban Stornnvater Management," JVater Enuiron. Res., 73(1), 5-14
(2001).
Da\is, A.P., Shokouhian, M., Sharma, H., Minami, C., and Winogradoff, D. "Water Quality
Improvement through Bioretention: Lead, Copper, and Zinc," 'J-·\'ater Enuiron. Res., accepted for
publication, August 2002.
Kim, H., Seagren, E.A., and Davis, A.P., "Engineered Bioretention for Removal of Nitrate from
Stonnwater Runoff," l1'EFTEC 2000 Conference Proceedings on CDROM Research
Symposium, Nitrogen Removal, Session 19, Anaheim CA., October 2000.
Hsieh, C.-h. and Davis, A.P. "Engineering Bioretention for Tre.atment of Urban Stonnwater
Runoff," H'atersheds 2002, Proceedings OTl CDRO/rf Research Symposium, Session 15, Ft.
Lauderdale, FL, Feb. 2002.
Prince George's County Department of Environmental Resources (PGDER), 1993. De.sign
Manual for Use of Bioretention in Stormwater· Management. Division of Environmental
Management, Watershed Protection Branch. Landover, MD.
U.S. EPA Office of Water, 1999. Stormwater Teclmology Fact Sheet: Bioretention. EPA 832-F-
99-012.
Weinstein, N. Davis, A.P. and Veeramachaneni, R "Low Impact Development (LID) Stonnwater
Management Approach for the Control of Diffuse Pollution from Urban Roadways," 5(11
Intemational Conference DiffusejNonpoint Pollution and Watershed Management
ProcRedings, C.S. Melching and Emre Alp, Eds. 2001 International Water Association
January 2003 California Stormwater BMP Handbook
New Development and Redevelopment
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TC-32
S"PERFORATED
PIPE IN 8" GRAVEL
JACKET
PARKING LOT SHEETFlOW
OPTIONAL SAND
FILTER LAYER
FILTER FABRIC
Schematic of a Bior-etention Facility (MDE, 2000)
8 of 8 California Stormwater BMP Handbook
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Bioretention
GRASS FILTER
STRIP
OPTIONAL
SAND LAYER
GRAVEL CURTAIN
DRAIN OVERFlOW
PLAN VIEW
January 2003
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ATTACHMENTC
I BMP NUMERIC SIZING
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t
-----+-----------+------+------+---
-----+------------__ ,_ --+---
-6-
1 EX. STREET liGHT Ex TRAffiC~!\ ~
---1(--
i
GRAPHIC SCALE
i i
(Ill ..... )
1 1Dcb •20tt.
i
A..C. PAvntENT O~Y
EX.F.H.~ I
I
/
s·
LEGEND
!.M.P. SYMBOL
BIORETENTlON FACILITY (TREATMENT CONTROL) f;.;.:-:<<<1
FEATURE
PAVEMENT AREA (CONC/ASPH)
SEEDED/LANDSCAPED AREA
ROOF
SURFACE FLOW
GRADE BREAK
SYMBOL
I:;)J I
BSSSrul l A -'1
·---·
AREA CONTRIBUTING TO BID-RETENTION BMP
BASIN 1 0.44 AC TO BIORETENTION BMP 1
BASIN 2 0.34 AC TO BIORETENTlON BMP 2
IF PLAN SIZE IS LESS THAN 24"x36".
THIS IS A REDUCED COPY.
SCALE PLAN ACCORDINGLY.
VARIES
POST-BWP IIIORETEHTION
A.C. PA~T 0'-9<1.AY
·cuss 2 P£RW£AIII£" CAL TRANS SPt:C. 68-1.025
BIOAETENTlON CTYP>
NOT TO SCAIL
~ ~EN=!IN~!~
7801 llaion Cdr Courl, S<ilt 100 Son Diogo, CA 92108
(619) 296-5565 Fax: (619) 296-5564
SUSIIP PROJICT PRIOIIITY PRIORITY PROJECT
fSHEETl CITY OF CARlSBAD I SHEETS I L__j ENGINEERING DEPARlMENT
DMA-IIlP PLAN FOR:
PALOMAR RETAIL CENTER
PROJECT NO.
·-------------------
I.M.P. AREAS CALCULATION
BIORETENTION FACILITIES (FOR WATER QUALITY ONLY)
Project Name:
Project Location:
APN:
K & S Project No:
DMA
NAME
Concrete I Pavement
Roof
Lanscape
PALOMAR RETAIL CENTER
PALOMAR AIRPORT ROAD, CARLSBAD CA
211-040-34-00
12-017
DMA P t P . t DMA os-rojec DMA area X
Surface Runoff Runoff
Area (SF) type Factor Factor
11,485 Concrete 1.0 11,485
7,517 Roof 1.0 7,517
300 Lanscaoe 0.1 30
Total 19,032
s oil Type
non I
IMP Sizing
Factor
lcwa Only)
0.041
DMA DMA P t P . t DMA os-roJec DMA area X S "I 01 Type
Surface Runoff Runoff I NAME Area (SF) type Factor Factor "On
Concrete I Pavement 12,081 Concrete 1.0 12,081
IMP Sizing
Roof 2,270 Roof 1.0 2,270 Factor
Lanscape 270 Lanscaoe 0.1 27 j(WQ Only)
Total 14,378 0.041
Date: 7/3/2012
IMP Name
Bioretention Facility No 1 l
Minimum Area Proposed
Area
761.281s.F. I 1,29811MP Area I
IMP Name
Bioretention Facility No 2 l
Minimum Area Proposed
Area
575.121S.F. I 750 liMP Area I
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ATTACHMENT D I CITY SUSMP FoRMS
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,:·~,
(tl t."•" . '•;:,";.~'-C II Y 0 I
CARLSBAD
STORM WATER
STANDARDS
QUESTIONNAIRE
E-34
Development Services
Land Development Engineering
1635 Faraday Avenue
760-602-2750
www.carlsbadca.gov
I' 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 Stormwater Management Plan (SUSMP). To
view the SUSMP, refer to the Engineering Standards (Volume 4, Chapter 2) at v • .v~.v.G&ri~L·adlo~tr:tc..vl::tc.nde>:ds.
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.
liECTION1 ___ -. ------· . ---···
Does your project meet one or more of the following criteria: YES NO
1. Hou!l.l1Sl !Jl.bdlvlf!.fl!l§. P,f 10 or more dwelling unit§.. Examples: single family homes, multi-family homes, f condominium and apartments "
2. Commercial-qtHtar than 1-acre. Any development other than heavy industry or residential. Examples: hospitals;
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.
3. Heavv lnduJttfalllndustrv-qt!Pter than 1 acre. Examples: manufacturing plants, food processing plants, metal "
working facilities, printing plants, and fleet storage areas (bus, truck, etc.). ,.
4. Automotive reoair §hop. A facility categorized in any one of Standard Industrial Classification (SIC) codes 5013,
5014, 5541,7532-7534, and 7536-7539 ...
5. Restaurants. Any facility that sells prepared foods and drinks for consumption, including stationary lunch counters
and refreshment stands selling prepared foods and drinks for immediate consumption (SIC code 5812), where the p• 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.
E-34 Page 1 of3 REV 1/14/11
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-~~'~ '"'' ~ CtlY OF
CARLSBA.D
STORM WATER
STANDARDS
QUESTIONNAIRE
E-34
Development Ser-vices
Land Development Engineering
1635 Faraday Avenue
760-602-2750
www.carlsbadca.gov
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 I ' twerffit-five percent (25%) or greater. •'
Envlr~mentally Sensitive Area fESAt All development located within or directly adjacenf to or discharging
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 1,./
the area of imperviousness of a proPosed project site 1 0% or more of its naturally occurring condition.
Parlclng lot. Area of 5,000 square feet or more, or with 15 or more parlc:ing spaces, and potentially exposed to urban .•·
runoff .;
Streets, roads. highways. and freeways. Any paved surface that is 5,000 square feet or greater used for the ;.. transportation of automobiles, trucks, motorcycles, and other vehicles
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10. Btl!.fl ~gLine Out/!1§.. Serving more than 100 vehicles per day and greater than 5,000 square feet i.
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%. t,. ..
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 Project4. ' .. .. 1 EnVIronmentally Sensitive Areas mclude but are not limited to all Clean Water Act Section 303(d) 1mpa1red water bodies, areas des1gnated as Areas of Special
Biological Significance by the State Water Resources Control Board 0/IJal.er 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 0/IJater 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 fiows 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:
SectJOD 1 RttU!ts:
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 of3 REV 1/14/11
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STORM WATER
STANDARDS
QUESTIONNAIRE
E-34
Development Services
Land Development Engineering
1635 Faraday Avenue
760-602-2750
www.carlsbadca.gov
r.;;;------------------~CTION2 ---------------------------------~--· --.-J SIGNIFICANT REOEVELOPMENT -----
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
Proiect *? v
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 PDP r~uirements" 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 t. 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 PDP 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 defimtton see Footnote 4 on page 2
-·-----------~_] SECTJOH3
Address:
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 rt of these ~ uirements, I will inco rate low im act develo ment strat ies throu hout m
Applicant lnfonnation and Signature Box This Box for City Use Only
Assessor's Parcel Number(s): City Concurrence: I YES I NO
I I
Applicant Name: Applicant Title: By:
Date:
Applicant Signature: Date: Project 10:
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