HomeMy WebLinkAboutCT 04-01; POINSETTIA RIDGE; STORM WATER MANAGEMENT PLAN; 2009-11-03ENGINEERING \O
Professional Civil Engineer and hand Surveyor *^ w
— ^
STORM WATER MANAGEMENT PLAN
for
Pomsettia Ridge, CT 04-01
Prepared for:
Warmington Residential California
3090 Pullman Street
Costa Mesa, CA 9262
714-434-4325
Proiect Site Address
S.E. Corner, Black Rail Road & Songbird Avenue, Carlsbad, CA 92009
Prepared bv:
Michael L Benesh, R.C.E. 37893
Dofe:
November 3,2009
JN 09-sd050
404 SOUTH LIVE OAK PARK ROAD • FALLBROOK, CA 92028
PHONE: 760 73 1 -6603 • FAX 760 897 -2 1 65 • E-MAIL: MBENESH@MLBENGINEERING.COM
Storm Water Management Plan (SWMP)
Poinsettia Ridge. CT 04-01
Engineering
Contents
SECTION 1. INTRODUCTION 1
SECTION 1.01 INTRODUCTION 1
SEaiON 2. VICINITYMAP 2
SECTION 3. PROJEa 3
SECTION 3.01 DESCRIPTION 3
SECTION 3.02 TOPOGRAPHY AND LAND USE 3
SEaiON 4. SITE MAP 4
SEaiON 5. IDENTIFICATION OF POLLUTANTS OF CONCERN 5
SECTION 5.01 ANTICIPATED POLLUTANTS 5
SECTION 5.02 RECEIVI NG WATERS 7
5.02.1 Beneficial Uses 7
5.02. l(i) Beneficial Uses for Inland Surface Waters 9
5.02.1(11) Beneficial Uses for Groundwater 9
SECTION 5.03 303(D) STATUS 9
SECTION 5.04 PRIMARY AND SECONDARY POLLUTANTS OF CONCERN 9
SEaiON 6. CONDITIONS OF CONCERN 10
SECTION 6.01 EXISTING AND POST CONSTRUCTION DRAINAGE 10
SECTION 6.02 SOIL CHARACTERISTICS H
SECTION 6.03 DOWNSTREAM CONDITIONS OF CONCERN 12
SEaiON 7. LID SITE DESIGN BMPS 12
SECTION 7.01 MAINTAIN PRE-DEVELOPMENT RAINFAL RUNOFF CHARACTERISTICS 12
7.01.1 BMP-1 Minimize Impervious Areas 12
7.01.2 BMP-2 Conserve Natural Areas 13
7.01.3 BMP-3 Minimize Directly Connected Impervious Areas 13
7.01.4 BMP-4 Maximize Canopy Interception 13
SECTION 7.02 PROTECT SLOPES AND CHANNELS 14
7.02.1 BMPS Convey Runoff Safely from the Tops of Slopes 14
7.02.2 BMPS Vegetate Slopes with Native of Drought Tolerant Vegetation 14
7.02.3 BMP-7 Stabilize Permanent Channel Crossings 14
7.02.4 BMPS Energy Dissipaters 14
7.02.5 BMP-9 Minimize disturbances to natural drainages 14
SEaiON 8. SOU RCE CONTROL BM PS 14
SECTION 8.01 OUTDOOR MATERIAL STORAGE AREAS 14
SECTION 8.02 TRASH STORAGE AREAS 15
SECTION 8.03 INTEGRATED PEST MANAGEMENT SYSTEMS 15
8.03.1 BMP-12 Reduce Pesticide Use 15
8.03.2 BMP-13 Educational Material 15
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SECTION 8.04 EFFICIENT IRRIGATION SYSTEMS AND LANDSCAPE DESIGN 16
8.04.1 BMP-14 Rain Shutoff Devices 16
8.04.2 BMP-15 Landscape and Irrigation Design 16
8.04.3 BMP16 Flow Reducers or Shutoff Valves 16
SECTION 8.05 STORM WATER CONVEYANCE SYSTEM STENCILING AND SIGNAGE 16
8.05.1 BMP-17 Catch Basin Stenciling 16
SEaiON 9. BMPS APPLICABLE TO INDIVIDUAL PRIORITY PROJEa CATEGORIES 16
SECTION 9.01 RESIDENTIAL DRIVEWAYS AND GUEST PARKING 17
9.01.1 BMP-20 Driveway Design 17
9.01.2 Uncovered Guest Parking 17
SEaiON 10. TREATMENT CONTROL BMP'S 17
SEaiON 11. STORM WATER BMP MAINTENANCE 17
SEaiON 12. SUMMARY CONCLUSIONS 17
SEaiON 13. CERTIFICATION 18
Attachment A - site Plan A-l
Attachment B - Computation Sheet for Runoff Coefficients B-l
Attachment C - Drainage Study C-l
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Section 1. Introduction
Section 1.01 Introduction
The purpose of this SWMP is to address the water quality impacts from the proposed
improvements on the Poinsettia Ridge, formerly the Yamamoto Property Subdivision
(CT 04-01). Best Management Practices (BMPs) will be utilized to provide a long-term
solution to water quality. This SWMP is also intended to ensure the effectiveness of the
BMPs through proper maintenance that is based on long-term fiscal planning. The
SWMP is subject to revisions as needed by the engineer.
"The requirement to implement storm water BMP requirements for development
projects is based on Section 402 (p) of the CleanWater Act. The Federal Clean Water
Act amendments of 1987 established a framework for regulating storm water
discharges from municipal, industrial, and construction activities under the NPDES
program. Under the Federal Clean Water Act, municipalities throughout the nation are
issued a Municipal NPDES Permit. The primary goal of the Municipal Permit is to stop
polluted discharges from entering the storm water conveyance system and local
receiving and coastal waters. In California, the State Water Resources Control Board
(SWRCB), through the nine Regional Boards, administers the NPDES storm water
municipal permitting program. Based on the San Diego Municipal Permit issued by the
San Diego Regional Board, the City is required to develop and implement permanent
storm water BMPs addressing pollution from new development projects.
The City of Carlsbad's Storm Water Management and Discharge Control Ordinance
(Carlsbad Municipal Code Chapter 15.12), requires that all new development and
redevelopment activities comply with the storm water pollution prevention
requirements. These storm water pollution prevention requirements, which ore
described in detail in Section 2.3, "Permanent Storm Water Best Management
practices Selection Procedure," ore site specific and vary based on the project's
potential impact on receiving water quality."
By definition, detached residential projects of more than 10 units, of which the
Poinsettia Ridge project is one, are classified as "priority projects". See the City of
Carlsbad's Stormwater Standards Questionaire in Attachment D.
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Section 2. Vicinity Mop
Figure 2.1: Vicinity Map
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Section 3. Project
Section 3.01 Description
The project is a five acre site located within the 16 lot Carlsbad Tract No. 04-01
Subdivision in the City of Carlsbad, California.
The site is bordered by Black Rail Road to the West, Songbird Avenue and CT 00-13 to
the North, CT 99-10 to the South and CT 92-3 to the East.
The site is adjacent to single family homes on South, East and North. The site is
adjacent to agricultural land to the West.
The proposed project will place 16 single family residences on the existing building
pods put in place as part of the grading plan for CT 04-01. Street and utility
improvements are existing as well. The amount of anticipated grading is
approximately 800 cubic yards for forms and footings as the pads will remain at their
existing grade.
Section 3.02 Topography and Land Use
The site is currently vacant with 16 graded pads. There are two paved streets on site
which were built to sere the project. Half of the pads of the subdivision front along
Thrasher Place and the other half of the pads front along Surf Crest Avenue. Storm
water runoff from the Lots fronting along Thrasher Place will either enter an existing
storm drain catch basin at the southerly end of Thrasher Place which takes the runoff
out to a catch basin on the easterly side of Block Roil Road, or will enter on existing
gunite ditch that runs along the southerly subdivision boundary and curb outlets onto
Black Rail Rood.. From there, it continues southerly along Block Rail Road to a storm
drain inlet 400 feet southerly of the site. The storm drain system outlets to a natural
drainage area southwesterly of the intersection of Black Rail Rood and Aviara
Parkway, approximately 1500 feet southwesterly of the project site.
The lots fronting Surf Crest Avenue will hove their runoff drained to Surfcrest and carried
northerly to Songbird Avenue. The remainder of the slopes along the easterly
subdivision boundary drain to an existing gunite ditch along the easterly property line,
then northerly to Songbird Avenue. Once in Songbird Avenue, runoff continues
northerly and easterly, along Cabella Place, and Docena Road to a storm drain
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system in the Aviara development. This storm drain system outlets to a natural
drainage area approximately 1500 feet easterly of the project site.
Through a series of storm drain culverts and natural drainage areas the storm water
runoff from this site eventually reaches the Batiquitos Lagoon and the Pacific Ocean.
The construction of the homes on the project will not alter the existing drainage
pattern. There will be on increase in the impervious area due to the homes being
constructed.
Section 4. Site Mop
The Project site map is included in Attachment A at the bock of this report.
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Section 5. Identification of Pollutants of Concern
Section 5.01 Anticipated Pollutants
Genera/ Pollutant Categories
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
Develooment
X X X P(l) P(2) P X
Commercial
Development
>100,000 ft2
p(i) p(i) P(2) X P(5) X P(3) P(5)
Automotive
Repair Shops X X(4)(5) X X
Restaurants X X X X
Hillside
Development
>5,000 ft2
X X X X X X
Paricing Lots
P(l) P(l) X X P(l) X P(l)
Streets,
Highvy/ays &
Freeways
X P(l) X X(4) X P(5) X
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.
The anticipated pollutants for a residential development like this, as identified in Table
1 above, are:
• Sediment: Sediments ore 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
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aquatic organisms survival rates, smother bottom dwelling organisms, and
suppress aquatic vegetation growth.
• 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 Runoff are fertilizers
and eroded soils. Excessive discharge of nutrients to water bodies and 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.
• Trasii & Debris: Trash (such as paper, plastic, polystyrene packing foam, and
aluminum materials) and biodegradable organic matter (such as leaves, grass
cuttings, and food waste) ore general waste products on the landscape. The
presence of trash and 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. In addition, 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 OS hydrogen sulfide.
• 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.
• Oil & Grease: Oil and grease are characterized as high-molecular weight
organic compounds. Primary sources of oil and grease ore 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 ore 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.
• Bacteria & Virus: Pathogens (bacteria and viruses) are ubiquitous
microorganisms that thrive under certain environmental conditions. Their
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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.
Pesticides: Pesticides (including herbicides) ore chemical compounds
commonly used to control nuisance growth or prevalence of organisms.
Excessive or improper application of a pesticide may result in runoff containing
toxic levels of its active ingredient.
Section 5.02 Receiving Waters
San Juan Santa Margarita San Luis Rey X Carlsbad
San Dieguito Penasquitos San Diego Pueblo San Diego
Sweetwater Otay Tiiuana
Number Name
904.51 Batiquitos
5.02.1 Beneficial Uses
The beneficial uses for the hydrologic unit ore included in Tables 3.1 and 3.2, below.
These tables have been extracted from the Water Quality Control Plan for the San
Diego Basin. The beneficial uses are defined as follows:
• 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: Includes uses of water for farming, horticulture, or
ranching including, but not limited to, irrigation, stock watering, or support of
vegetation for range grazing.
• IND- Industrial Services Supply: Includes uses of water for industrial activities that do
not depend primarily on water quality including, but not limited to, mining, cooling
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water supply, hydraulic conveyance, gravel washing, fire protection, or oil well re-
pressurization.
• BIOL - Preservation of Biological Habitats of Special Significance: Includes uses of
water that support designated areas or habitats.
• EST- Estuarine Habitat: Includes uses of water that support estuarine ecosystems,
including but not limited to preservation or enhancement of estuarine habitats,
vegetation, fish, shellfish, or wildlife.
• MAR- Marine Habitat: Includes uses of water that support marine ecosystems,
including but not limited to preservation or enhancement of marine habitats,
vegetation, fish, shellfish, or wildlife.
• MIGR- Migration of Aquatic Organisms: Includes uses of water that support habitats
necessary for migration, acclimatization between fresh and salt water, or other
temporary activities by aquatic organisms, such as anadromous fish.
• RARE- Rare, threatened or endangered species: Includes uses of water necessary,
al least in part, for the survival and successful maintenance of plant or animal
species established under State or Federal Low as rare, threatened or endangered.
• 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.
• SPWN- Spawning, reproduction or early development: Includes uses of water that
support high quality aquatic habitats suitable for reproduction and early
development of fish.
• 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.
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5.02.1 (i) Beneficial Uses for Inland Surface Waters
The inland surface waters downstream of this project have the following beneficial
uses as shown on Table 3.1.
Table 3.1- Beneficial Uses for Inland Surface Waters
Hydrologic Unit
1
ee O
< z g
ca
1—
IU
ee
<
ee
o RARE O
IU ee
CN u IU ee
Z $ a.
i/i WILD 904.51
• Existing Beneficial Use
5.02.1 (ii) Beneficial Uses for Groundwater
The ground water for this project has the following beneficial uses as shown in Table
3.2.
Table 3.2 - Beneficial Uses for Groundwater
Hydrologic Unit MUN ee O
<
O
z
1
g
CO
1—
i/i
IU MAR MIGR RARE REC 1 REC 2 SPWN WILD 904.51 • • •
• Existing Beneficial Use
Section 5.03 303(d) Status
According to the California 2006 303(d) list published by the Son Diego Regional Water
Quality Control Board, the water bodies that are associated with this project, i.e. the
Batiquitos Lagoon, ore not impaired.
Section 5.04 Primary and Secondary Pollutants of Concern
As there are no impaired waters downstream of the project, there ore no primary
pollutants of concern. Secondary pollutants of concern would be the anticipated
pollutants identified in Section 5.01.
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Section 6. Conditions of Concern
Section 6.01 Existing and Post Construction Drainage
The streets and grading and drainage improvements for the residences have already
been constructed. As the project is only the construction of houses on the existing
building pads, the proposed project will not alter drainage patterns on the site or the
surrounding area. The Storm water discharge points will not divert runoff from existing
conditions.
Approximately 0.9 acres of open ground will be covered by the single-family
residences and appurtenant driveways. This area plus the approximately 1.1 acres of
existing paved streets and sidewalks will make a total of 2.0 acres of impervious
surfaces on the site. Thus, the impervious area on the site will increase from 0.31 acres
in the original undeveloped condition to 2.0 acres after completed development, or
from approximately 6% to 40% impervious area.
This change in land use will increase the composite runoff coefficient, of the project,
from C=0.38 to C=0.57. Also, the total peak 10 year storm flow rote will increase from
6.0 cfs under the undeveloped condition to 7.3 cfs under the proposed condition. A
detailed description of the drainage patterns and flows are discussed in the Drainage
Report submitted to the City of Corlsbad for this development. A copy of this report is
included in Attachment C to this report. See Table 4.1 and Attachment D for
Impervious area calculations.
Table 4.1 - Impervious Areas & Runoff Coefficients
Construction site area 5.0 acres
Percentage impervious area before construction 6 %
Runoff coefficient before construction H) 0.38
Percentage impervious area after construction 40 %
Runoff coefficient after construction (i) 0.57
Anticipated off-site storm water flow on to the
construction site 0 cfs
(1) Calculations are shown in Attachment C
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The runoff from this site both in the existing state and the proposed development is
directed to two distinct outflows. Both outflows lead to natural drainage areas via
paved streets and storm drain systems. The existing natural environment serves as a
bio-filter for the runoff generated from the area.
Each residential lot will incorporate the following post construction BMP's to reduce
and treat the amount of storm runoff leaving the site:
• Vegetated Swales will be incorporated in to the yard drainage system for each
lot, treating the roof and yard runoff before it leaves each lot.
• A strip of pervious interlocking paving blocks shall be utilized at the downstream
end of the driveways for each lot where the driveway drains to the street to
reduce and break up the impervious area created by the subdivision and
increase infiltration.
Refer to the Site Map in Attachment B for post construction BMP locations.
Summaries of the post-construction water quality flows ore included in Table 4.2. The
flows were developed using a Precipitation of 0.2 inches per hour developed by the
County.
Table 4.2 - Post Construction Water Quality Flows
Outfall Tributary Area
(Acres) Qio QwQ
A (East) 1.5 2.3 0.17
B (West) 2.7 4.0 0.31
C (South) 0.65 1.0 0.07
(1) Calculations ore shown in Attachment D
Section 6.02 Soil Characteristics
The project area consists of soil group D with an saturated infiltration rate of from 0.02
to 0.10 in./hr. The project will not hove slopes steeper than 2:1. All slopes will include
slope protection such as berms or brow ditches at the tops of slopes, and landscaping
and iriigotion to limit the potential for erosion. (Note: Information regarding soils group
infiltration rates is from the Ventura Countywide Stormwater Quality Management
Program, W:\Stormwater\documents\workproducts\landuseguidelines\app3.doc.)
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Section 6.03 Downstream Conditions of Concern
Downstream of the project site the storm water runoff will be conveyed either by a city
maintained storm drain system or a natural drainage channel until it reaches the
Batiquitos Lagoon. The outlets for the city storm drains are adequately protected to
limit erosion and the natural drainage channels do not have signs of high amounts of
erosion or flooding. The natural drainage channels are located on a golf course and
ore adequately maintained.
Section 7. LID Site Design BMPs
The City of Carlsbad Standard Urban Storm Water Mitigation Plan requires all projects
subject to standard or priority project requirements to implement all applicable site
design BMPs listed below. Applicants may employ alternative comparable and
equally effective site design (including requirements applicable to individual priority
project categories), satisfactory to the City Engineer.
Projects ore encouraged to address these objectives through the creation of a
hydrologicolly functional project design that attempts to mimic the natural hydrologic
regime. Mimicking a site's natural hydrologic regime may be pursued by:
• Reducing imperviousness, consen/ing natural resources and areas, maintaining
and using natural drainage courses in the storm water conveyance system, and
minimizing clearing and grading that is necessary for the project.
• Providing runoff storage measures dispersed uniformly throughout a site's
landscape with the appropriate use of a variety of detention, retention, and
runoff practices.
• Implementing on-lot hydrologicolly functional landscape design and
management practices.
Section 7.01 Maintain Pre-Development rainfal runoff characteristics
Post-development peak storm water runoff discharge rates and velocities are controlled
to maintain or reduce pre-development development downstream erosion by applying
the following site design BMPs:
7.01.1 BMP-1 Minimize Impervious Areas
The project is designed to minimize the use of impen/ious areas in the following ways:
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• Streets areas hove been designed to meet the minimum City Standard widths of
36 feet from curb to curb.
• Sidewalks hove been constructed to minimum width allowed by the city.
• Building footprints have been limited by the use of two story buildings on all but
two lots.
• Driveway widths have been limited by the use of tandem parking in the
garages.
• Portions of the driveways will be constructed with unit pavers.
7.01.2 BMP-2 Conserve Natural Areas
The site is an in-fill project surrounded by developed properties, and was previously
used for agricultural purposes. Therefore there are no natural areas on the site to
consen/e.
7.01.3 BMP-3 Minimize Directly Connected Impervious Areas
The project is designed to minimize directly connected impervious areas in the
following ways:
• The downhill end of all the driveways that drain directly to the streets will be
constructed with unit pavers to disconnect the impervious areas. Drainage from
all other driveways will be directed into landscaped areas before entering
drainage systems.
• Rooftop drainage will be directed into the landscaped yard areas.
• Walkways and patios will be drained to landscaped areas.
7.01.4 BMP-4 Maximize Canopy Interception
Canopy interception and water conservation will be maximized consistent with the
Corlsbad Landscape Manual in the following ways:
• The project landscape plans coll for the planting of over 40 trees in the street
right-of-way and the slope areas. The original site hod only one large eucalyptus
tree before grading.
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Section 7.02 Protect Slopes and Channels
Slopes and channels are protected on the site by implementing the following site
design BMPs:
7.02.1 BMP-5 Convey Runoff Safely from the Tops of Slopes
Drainage from all building pods is directed owoy from the tops of slopes and on earth
berm is installed at the tops of slopes to eliminate runoff over the slopes. Slopes along
the tract boundary ore protected by concrete brow ditches to convey drainage
safely to the bottom of the site.
7.02.2 BMP-6 Vegetate Slopes with Native of Drought Tolerant Vegetation
The landscape plans calls for vegetated the slopes with a mix of drought tolerant
ground covers, bushes and trees in compliance with the Corlsbad Landscape Manual.
7.02.3 BMP-7 Stabilize Permanent Channel Crossings
There are no permanent channel crossings located on the project site.
7.02.4 BMP-8 Energy Dissipaters
All lined drainage ditches outlet to parkway culverts to eliminate the potential for
erosion. There are no lined ditches or storm drains that outlet into unlined channels.
7.02.5 BMP-9 Minimize disturbances to natural drainages
There ore no natural drainages on the site. The site has been completely graded in the
post.
Section 8. Source Control BMPs
Source control BMPs will consist of measures to prevent polluted runoff. The following
source control BMPs wholl be implemented on this site:
Section 8.01 Outdoor Material Storage Areas
This is a detached residential project and will not include any permanent outdoor
storage areas.
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Section 8.02 Trash Storage Areas
This is a detached residential project and will not include any central trash storage
areas. Individual homeowners will be required to use trash containers with attached
lids that exclude rain
Section 8.03 Integrated Pest Management Systems
Integrated pest management (IPM) 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. Pesticides ore
used only after monitoring indicates they ore needed according to established
guidelines. Pest control materials ore selected and applied in a manner that minimizes
risks to human health, beneficial and non-target organisms, and the environment.
The following source control BMP's shall be used on this project:
8.03.1 BMP-12 Reduce Pesticide Use
Common maintenance landscape areas will reduce the need for pesticide use in the
project design by:
• Planting pestresistont or well-adopted plant varieties such as native plants.
• Discourage pests by modifying the site and landscaping design.
8.03.2 BMP-13 Educational Material
This program will include an educational component directed at each homeowner.
The developer shall distribute IPM educational materials to future site residents/tenants.
Minimally, educational materials will address the following topics:
• Keeping pests out of 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 pests.
• Proper use of pesticides as a lost line of defense.
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Section 8.04 Efficient Irrigation Systems and Landscape Design
In compliance with the Water Conservation in Landscaping Act, the following source
control BMPs to reduce excessive irrigation runoff shall be implemented:
8.04.1 BMP-14 Rain Shutoff Devices
Commonly maintained landscaped areas shall employ rain shutoff devices to prevent
irrigation during and offer precipitation.
8.04.2 BMP-15 Landscape and Irrigation Design
Commonly maintained landscaped areas shall hove irrigation systems designed to
each landscape area's specific water requirements.
8.04.3 BMPl 6 Flow Reducers or Shutoff Valves
Commonly maintained landscaped areas shall use flow reducers or shutoff valves
triggered by a pressure drop to control water loss in the event of broken sprinkler
heads or lines.
Section 8.05 Storm Water Conveyance System Stenciling and Signage
The following source control BMPs to discourage illegal dumping shall be
implemented:
8.05.1 BMP-17 Catch Basin Stenciling
The developer will provide concrete stamping, porcelain tile, inset permanent marking
or equivalent as approved by the City of Carlsbad, for the on-site storm drain curb
inlet with prohibitive language (e.g., "No Dumping -1 Live Downstream"), satisfactory
to the City Engineer.
Section 9. BMPs Applicable to Individual Priority
Project Categories
All priority projects ore required to incorporate site design BMPs applicable to the
category of the project as identified in Section 5, Table 1.
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Section 9.01 Residential Driveways and Guest Parking
This project is a detached residential development and as such the following site
design BMPs shall be incorporated into this priority project:
9.01.1 BMP-20 Driveway Design
Driveways shall either have a three foot strip of interlocking pavers over an approved
sand or gravel base per the Soils Engineer's recommendations at their downhill end or
be designed to drain into adjacent landscaping.
9.01.2 Uncovered Guest Parking
Guest parking spaces on private property shall be designed to drain into adjacent
landscaping.
Section 10. Treatment Control BMP's
Priority projects are required to implement post construction structural treatment
control BMPs to treat the project runoff for the primary pollutants of concern.
Alternatively, a project proponent may elect to implement a combination of LID BMPs
that either disperse and infiltrate, or direct to bioretention facilities, the flows from all
impen/ious areas on-site. These BMPs are presumed to provide maximum extent
practicable treatment for all pollutants of concern; therefore no further
documentation of the treatment BMP selection process is required.
For this project all flows from on-site impervious areas ore being directed to
landscaped areas that disperse and infiltrate the storm water runoff.
Section 11. Storm Water BMP Maintenance
There are no proposed permanent treatment control BMP's.
Section 12. Summary Conclusions
This SWMP has been prepared in accordance with the Watershed Protection, Storm
water Management, and Discharge Control Ordinance and the Storm water
Standards Manual. This SWMP has evaluated and addressed the potential pollutants
associated with this project and their effects on water quality. A summary of the facts
and findings associated with this project and the measures addressed by this SWMP is
as follows:
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Storm Woter Managemenf Plan (SWMP)
Poinsettia Ridge, CT 04-01
• The beneficial uses for the receiving waters have been identified. None of these
beneficial uses will be impaired or diminish due to the construction and operation
of this project.
• The project will not significantly alter patterns on the site. The discharge points will
not be changed.
• Open areas and slopes will be landscaped to reduce or eliminate sediment
discharge.
• Interlocking concrete pavers will provide a disconnect between impervious
surfaces and reduce storm water runoff from the site.
• The combination of LID BMPs hove the capacity to disperse and infiltrate the flows
from all impervious areas on-site. These BMPs ore presumed to provide maximum
extent practicable treatment for all pollutants of concern; therefore no further
documentation of the treatment BMP selection process is required.
Section 13. Certification
This Storm Water Management Plan has been prepared under the direction of the
following Registered Civil Engineer. The Registered Civil Engineer attests to the
technical information contained herein and the engineering data upon which
recommendations, conclusions, and decisions are based.
Michael L. Benesh, RCE 3789
Exp. 3/31/11
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Attachnnent A - Site Plan
See Map in Folder.
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Attachment B - Computation Sheet for Runoff Coefficients
TOTAL SITE AREA 4.9 ACRES (A)
Existing Site Conditions
IMPERVIOUS AREA^ 0.3 ACRES (B)
IMPERVIOUS AREA RUNOFF COEFFICIENT^ 0.90 (C)
PERVIOUS AREA^ 4.6 ACRES (D)
PERVIOUS AREA RUNOFF COEFFICIENT* 0.35 (E)
COMBINED RUNOFF COEFFICIENT 0.38 [BC+DE]/A
Proposed Site Conditions
IMPERVIOUS AREA* 2.0 ACRES (F)
IMPERVIOUS AREA RUNOFF COEFFICIENT^ 0.90 (G)
PERVIOUS AREA' 2.9 ACRES (H)
PERVIOUS AREA RUNOFF COEFFICIENT" 0.35 (I)
COMBINED RUNOFF COEFFICIENT 0.57 [FG+HI]/A
Notes:
1. Includes paved areas, areas covered by buildings and other impervious areas.
2. 95% assumed.
3. Includes areas of vegetation, unpaved soil areas, and other pervious areas.
4. Runoff Coefficient for rural areas per Appendix IX, Soil Type D, San Diego Hydrology
Manual.
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Attachment C - Drainage Study
Refer to Drainage Study for Poinsettia Ridge, CT 04-01 prepared by MLB Engineering.
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Attachment D - Storm Water Standards Questionnaire
See the City of Carlsbad's Storm Water Standards Questionnaire on the following
pages.
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APPENDIX A
STORM WATER STANDARDS QUESTIONNAIRE
I INSTRUCTIONS:
This questionnaire must be completed by the applicant in advance of submitting for a development application
(subdivision and land use planning approvals and construction permits). The results of the questionnaire determine
the level of storm water pollution prevention standards applied to a proposed development or redevelopment
project. Many aspects of project site design are dependent upon the stonn water pollution protection standards
applied to a project.
Applicant 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. A staff determination that the development application is subject to more stringent storm water
standards, than initially assessed by the applicant, will result in the return of the development application as
incomplete.
If applicants are unsure about the meaning of a question or need help in determining how to respond to one or
more of the questions, they are advised to seek assistance from Engineering Department Development Sen/ices
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, applicants for construction pemiits
must also complete, sign and submit a Construction Activity Storm Water Standards Questionnaire.
To address pollutants that may be generated from new development, the City requires that new development and
significant redevelopment priority projects incorporate Permanent Storm Water Best Management Practices
(BMPs) into the project design, which are described in Chapter 2 of the City's Storm Water Standards Manual This
questionnaire should be used to categorize new development and significant redevelopment projects as priority or
non-priority, to determine what level of stomri water standards are required or if the project is exempt.
1 is your project a significant redevelopment?
Definition:
Significant redevelopment is defined as the creation, addition or replacement of at least 5,000 square feet of
impervious surface on an already existing developed site.
Significant redevelopment inciudes, but is not limited to: the expansion of a buiiding footprint; addition to or
replacement of a structure; structural development including an increase in gross floor area and/or exterior
construction remodeling; replacement of an impervious surface that is not part of a routine maintenance activity;
and iand disturbing activities related with structural or impervious surfaces. Replacement of impervious surfaces
inciudes any activity that is not part of a routine maintenance activity where impervious materiai(s) are removed,
exposing underlying soil during construction.
Note: If the Significant Redevelopment results in an increase of less than fifty percent of the impervious surfaces of
a previously existing development, and the existing development was not subject to SUSMP requirements, the
numeric sizing criteria discussed in Table 3 of 2.3.3.4 applies only to the addition, and not to the entire
development.
2. if your project IS considered significant redevelopment, then please si<ip Section 1 and proceed with Section
2.
3. if your project IS NOT considered significant redevelopment, then piease proceed to Section 1.
21 SWMP Rev 6/4/08
SECTION 1
NEW DEVELOPMENT
PRIORITY PROJECT TYPE
Does you project meet one or more of the following criteria: YES NO
1. Home subdivision of 100 units or more.
Includes SFD, MFD, Condominium and Apartments X
2. Residential develooment of 10 units or more.
Includes SFD, MFD, Condominium and Apartments X
3. Commercial and industrial develooment areater than 100.000 sauare feet indudina oarldna areas.
Any development on private land that is not for heavy industrial or residential uses. Example: Hospitals,
Hotels, Recreational Facilities, Shopping Malls, etc. X
4. Heaw Industrial/ Industrv areater than 1 acre (NEED SIC CODES FOR PERMIT BUSINESS TYPES^
SIC codes 5013, 5014, 5541, 7532-7534, and 7536-7539 X
5. Automotive reoair shoo.
SIC codes 5013, 5014, 5541, 7532-7534, and 7536-7539
6. A New Restaurant where the land area of develooment is 5.000 sauare feet or more indudina Dart<ina
areas.
SIC code 5812
x
7. Hillside develooment
(1) greater than 5,000 square feet of impen/ious surface area and (2) development will grade on any
natural slope that is 25% or greater
X
8. Environmentallv Sensitive Area (ESA).
Impervious surface of 2,500 square feet or more located within, "directly adjacent"^ to (within 200 feet),
or "discharging directly to"^ receiving water within the ESA^
x
9. Parkina lot
Area of 5,000 square feet or more, or with 15 or more parking spaces, and potentially exposed to urban
runoff
x
10. Retail Gasoline Outlets - servina more than 100 vehicles oer dav
Serving more than 100 vehicles per day and greater than 5,000 square feet x
11. Streets, roads, drivewavs. hiahwavs. and freewavs.
Project would create a new paved surface that is 5,000 square feet or greater. X
12. Coastal Development Zone.
Within 200 feet of the Pacific Ocean and (1) creates more than 2500 square feet of impermeable
surface or (2) increases impermeable surface on property by more than 10%.
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 Count
of San Diego; and any other equivalent environmentally sensitive areas which have been identified by the Copemiittees.
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.
Section 1 Results:
If you answered YES to ANY of the questions above you have a PRIORITY project and PRIORITY project requirements DO
apply. A Stomi Water Management Plan, prepared in accordance with City Storm Water Standards, must be submitted at
time of application. Please check the "MEETS PRIORITY REQUIREMENTS" box in Section 3.
If you answered NO to ALL of the questions above, then you are a NON-PRIORITY project and STANDARD requirements
apply. Please check the "DOES NOT MEET PRIORITY Requirements" box in Section 3.
SWMP Rev 6/4/08
SECTION 2
SIGNIFICANT REDEVELOPMENT: YES NO
1. Is the project redeveloping an existing priority project type? (Priority projects
are defined in Section 1) X
If you answered YES, please proceed to question 2.
If you answered NO, then you ARE NOT a significant redevelopment and you ARE NOT subject to
PRIORITY project requirements, only STANDARD requirements. Please check the "DOES NOT MEET
PRIORITY Requirements" box in Section 3 below.
2. Is the project solely limited to one ofthe following:
a. Trenching and resurfacing associated with utility work? X
b. Resurfacing and reconfiguring existing surface parking lots? X
c. New sidewalk construction, pedestrian ramps, or bike lane on public
and/or private existing roads? X
d. Replacement of existing damaged pavement? X
If you answered NO to ALL of the questions, then proceed to Question 3.
If you answered YES to ONE OR MORE ofthe questions then you ARE NOT a significant redevelopment
and you ARE NOT subject to PRIORITY project requirements, only STANDARD requirements. Please
check
the "DOES NOT MEET PRIORITY Requirements" box in Section 3 below.
3. Will the development create, replace, or add at least 5,000 square feet of
impervious surfaces on an existing development or, be located within 200
feet of the Pacific Ocean and (1)create more than 2500 square feet of
impenneable surface or (2) increases impermeable surface on property by
morethan 10%?
X
If you answered YES, you ARE a significant redevelopment, and you ARE subject to PRIORITY project
requirements. Please check the "MEETS PRIORITY REQUIREMENTS" box in Section 3 below.
If you answered NO, you ARE NOT a significant redevelopment, and you ARE NOT subject to
PRIORITY project requirements, only STANDARD requirements. Please check the "DOES NOT MEET
PRIORITY Requirements" box in Section 3 below.
SECTION 3
Questionnaire Results:
MY PROJECT MEETS PRIORITY REQUIREMENTS, MUST COMPLY WITH PRIORITY
PROJECT STANDARDS AND MUST PREPARE A STORM WATER MANAGEMENT PLAN FOR
SUBMITTAL AT TIME OF APPLICATION.
MY PROJECT DOES NOT MEET PRIORITY REQUIREMENTS AND MUST ONLY COMPLY
WITH STANDARD STORM WATER REQUIREMENTS.
Applicant Information and Signature Box This Box Jor City Use Only
Address: Assessors Parcel Number(s):
SE Cor. of Black Rail & Songbird 215-041-30 thru 45
Applicant Name: Applicant Title:
Applicant Signature: Date:
City Concurrence:
By:
Project ID:
SWMP Rev 6/4/08