HomeMy WebLinkAboutCT 02-24; VILLAGES OF LA COSTA GREENS 1.11/.13; STORM WATER MGMT PLAN; 2004-08-11STORM WATER
MANAGEMENT PLAN
for
LA COSTA GREENS
NEIGHBORHOODS 1.11 & 1.13
City of Carlsbad, California
Prepared for:
John Laing Homes
6183 Paseo Del Norte
Carlsbad, CA 92009
w.o. 2341-18
August 11, 2004
Eric Mosolgo, R.C.E.
Water Resources Department Manager
Hunsaker & Associates San Diego, Inc. • O z o ly
li Ie4i 6
•z.
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La Costa Greens Neighborhoods 1.11 & 1.13
storm Water Management Plan
TABLE OF CONTENTS
CHAPTER 1 - Executive Summary
1.1 Introduction
1.2 Summary of Pre-Developed Conditions
1.3 Summary of Proposed Development
1.4 Results and Recommendations
1.5 Conclusion
CHAPTER 2 - Storm Water Criteria
2.1 Regional Water Quaiity Control Board Criteria
2.2 City of Carlsbad SUSMP Criteria
CHAPTER 3 - Identification of Typical Pollutants
3.1 Anticipated Pollutants from Project Site
3.2 Sediment
3.3 Nutrients
3.4 Trash & Debris
3.5 Oxygen-Demanding Substances
3.6 Oil & Grease
3.7 Bacteria & Viruses
3.8 Pesticides
CHAPTER 4 - Conditions of Concern
4.1 Receiving Watershed Descriptions
4.2 Pollutants of Concern in Receiving Watersheds
CHAPTER 5 - Flow-Based BMPs
5.1 Design Criteria
5.2 Vortechs Treatment Units
5.3 Pollutant Removal Efficiency Table
5.4 Maintenance Requirements
5.5 Schedule of Maintenance Activities
5.6 Annual Operations & Maintenance Costs
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La Costa Greens Neighborhood 1.11 & 1.13
storm Water Management Plan
CHAPTER 6 - Source Control BMPs
6.1 Landscaping
6.2 Urban Housekeeping
6.3 Automobile Use
6.4 Site Design BMPs
CHAPTER 7 - Site BMP Design (Vortechs Treatment Units)
7.1 BMP Locations
7.2 Determination of Treatment Flows
7.3 Vortechs Treatment Unit Selections
CHAPTER 8 - References
List of Tables and Figures
Chapter 1 - Watershed Map
Chapter 3 - Pollutant Category Table
Chapter 4 - San Diego Region Hydrologic Divisions
Chapter 4 - Combined-1998 and Draft 2002 Section 303(d) Update
Chapter 4 - Beneficial Uses of Inland Surface Waters
Chapter 4 - Water Quality Objectives
Chapter 6 - Pollutant Removal Efficiency Table (Flow-Based BMPs)
Chapter 7 - 85^*^ Percentile Rainfall Isopluvial Map
Chapter 7 - Neighborhood BMP Location Maps
Chapter 7 - Design Runoff Determination Summary Table
Chapter 7 - Vortechs Unit Treatment Capacity Table
Chapter 7 - Vortechs System Data
Attachments
BMP Location Map
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La Costa Greens Neighborhood 1.11 & 1.13
Storm Water Management Plan
CHAPTER 1 - EXECUTIVE SUMMARY
1.1 - Introduction
Phase 1 ofthe La Costa Greens project site is located north of Alga Road, south of
the proposed extension of Poinsettia Lane, and east of the La Costa Golf Course.
Neighborhood 1.11 is located in the southwestern portion ofthe development, west
of Alicante Road, east of the golfcourse, north of Neighborhood 1.14, north ofthe
SDG&E easement and south of Neighborhood 1.10. Neighborhood 1.13 is located
at the southwestern corner of the development, west of Alicante Road, east of the
golfcourse, north of Alga Road and south of Neighborhood 1.11. Neighborhoods
1.11 & 1.13 are two (2) of seven (7) subdivisions within the La Costa Greens Phase I
development. An exhibit showing the location of each treatment unit and the
breakdown of the areas tributary to each treatment unit is included on the following
page.
Neighborhood 1.11
All runoff from Neighborhood 1.11 will drain to a proposed storm drain outlet located
adjacent to Goldstone Road in the San Diego Gas & Electric (SDGE) easement. No
offsite runoff drains into or is collected in the Neighborhood 1.11 storm drain system.
All stormwater draininglo this location will be treated in one treatment unit prior to
discharge.
Neighborhood 1.13
All Runoff from Neighborhood 1.13 will drain to a proposed storm drain outlet located
near the intersection of Goldstone Road and Street GG in Neighborhood 1.14. Storm
drain flow discharges to an existing 42-inch RCP in the Alga Road storm drain
system. Runoff from Neighborhood 1.13, 1.14, the southern portion of 1.12 and the
adjacent residential development east of La Costa Greens Phase 1 will also drain to
this storm drain outlet location. All stormwater draining to this location will be treated
in one treatment unit prior to discharge.
Runoff from both developments ultimately drains to an unnamed tributary of San
Marcos Creek. Flow from this tributary eventually discharges into San Marcos
Creek towards the Batiquitos Lagoon.
Perthe CityofCarlsbad SUSMP, the La Costa Greens Neighborhoods 1.11 & 1.13
projects are classified as Priority Projects and subject to the City's Permanent Storm
Water BMP Requirements.
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LEGEND
WATERSHED TRIBUTARY
TO TREATMENT UNIT •
TREATMENT UNIT ^
OFFSITE RUN-ON LOCATION
LA COSTA GREENS
POST-CONSTRUCTION
BMP LOCATION EXHIBIT
FLOW-BASED BMP FOR
NEIGHBORHOOD 1.08, OFFSrrE DEVELOPMEl
AND AUCANTE ROAD
FLOW-BASED BMP FOR
NEIGHBORHOOD 1.09,
1.10, A PORTION OF 1.12,
AND OFFSrrE DEVELOPMENT
FLOW-BASED BMP FOR
NEIGHB0RH00D1.il
FLOW-BASED BMP FOH
NHGHBORHOOD 1.13,1.14,
PORTION OF 1.12,
AUCANTE ROAD, AND
OFFSITE DEVELOPMENT
Ri\0330\a,Hyc(\Slte Location Map 8.5xU-lU.dv»gC 1275]Jun-ia-20Q3a4i45
LEGEND
WATERSHED TRIBUTARY
TO TREATMENT UNIT
TREATMENT UNIT 0
OFFSITE RUN-ON LOCATION
LA COSTA GREENS
POST-CONSTRUCTION
BMP LOCATION EXHIBIT
FLOW-BASED BMP FOR
NEIGHBORHOOD 1.08, OFFSrrE DEVELOPMEl
AND AUCANTE HOAD
FLOW-BASED BMP FOR
NEIGHBORHOOD 1.09,
1.10, A PORTION OF 1.12,
AND OFFSrrE DEVELOPMENT
FLOW-BASED BMP FOR
NEIGHB0RHQQD1.il
FLOW-BASED BMP FOH
NEIGHBORHOOD 1.13,1.14,
PORTION OF 1.12.
AUCANTE ROAD, AND
OFFSrrE DEVELOPMENT
R>\Q330\8iHycl\Slte Location Mop 8.5xll-U3.dwgC 1275]Jun-ia-SQ03a4i44
La Costa Greens Neighborhood 1.11 & 1.13
Storm Water Management Plan
This Storm Water Management Plan (SWMP) has been prepared pursuant to
requirements set forth in the City of Carlsbad's "Standard Urban Storm Water
Mitigation Plan (SUSMP)." All calculations are consistent with criteria set forth by
the Regional Water Quality Control Board's Order No. 2001-01, and the City of
Carlsbad SUSMP.
This SWMP recommends the location and sizing of site Best Management Practices
(BMPs) which include two (2) Vortechs treatment units (see BMP Location Map in
this chapter).
Furthermore, this report determines anticipated project pollutants, pollutants of
concern in the receiving watershed, peak flow mitigation, recommended source
control BMPs, and methodology used forthe design of flow-based and volume-
based BMPs.
CITY or
SAN MARCOS
THE GREENS
1.11, 1.15 & 1.14
VICINITYMAF
NTS
1.2 - Summarv of Pre-Developed Conditions
Phase 1 ofthe La Costa Greens project site is located north of Alga Road, south of
the proposed extension of Poinsettia Lane, and east of the La Costa Golf Course.
Neighborhoods 1.11 & 1.12 are located to the southern extent ofthe development,
bisected by Alicante Road, east ofthe golfcourse, south of Neighborhood 1.10 and
south of Poinsettia Road.
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La Costa Greens Neighborhood 1.11 & 1.13
storm Water Management Plan
Runoff from the site in natural conditions drains to the San Marcos Creek. The
Regional Water Quality Control Board has identified San Marcos Creek as part of
the Carlsbad Hydrologic Unit, San Marcos Hydrologic Area, and the Batiquitos
Hydrologic Subarea (basin number 4.51).
1.3 - Summarv of Proposed Development
Neighborhood 1.11
The La Costa Greens Neighborhood 1.11 will include construction of two (2)
proposed roads, grading of the proposed site to make it suitable for construction of
single-family residential dwellings, construction of underground utilities typically
associated with residential developments, and the construction of 35 residences.
The total project consists of 129 residential lots and 8 open space lots, for a total
area of 34.22 acres (21.15 acres and 12.07 acres respectively). Approximately 35%
will remain undeveloped.
The proposed treatment unit will located offline from the main storm drain system
and is proposed in the vicinity of Goldstone Road to the South West corner of
Neighborhood 1.11 (see Ultimate Condition Site Map included in the pocket of the
this report).
Neighborhood 1.13
The La Costa Greens Neighborhood 1.13 project will include construction of four (4)
proposed roads, grading ofthe proposed site to make it suitable for construction of
single-family residential dwellings, construction of underground utilities typically
associated with residential developments, and the construction of 61 residences.
The total project consists of 129 residential lots and 8 open space lots, for a total
area of 34.22 acres (21.15 acres and 12.07 acres respectively). Approximately 35%
will remain undeveloped.
The offsite developed areas, which will drain to the storm drain outlet located in
Neighborhood 1.14 have been quantified in two hydrology studies; "Hydrology &
Hydraulic Study - La Costa Greens Phase 1", prepared by O'Day Consultants May
25, 2002, and "Tentative Map Drainage Study for La Costa Greens - Phasel
Neighborhoods 1.08 through 1.14," prepared by Hunsaker & Associates San
Diego, Inc. April 17, 2003. The O'Day report identified a total of 13 acres of offsite
developed area that contribute flow to the La Costa development in the vicinity of
Neighborhood 1.12 and 1.13. The Hunsaker & Associates report identified one run
on location near the southeast corner of Neighborhood 1.12 and the northeast
corner of Neighborhood 1.13 consisting of 13 acres of area. The Quadrangle Map
Watershed Exhibit for La Costa Greens illustrates the extent of offsite areas
draining to the La Costa Greens Phase I proposed development and has been
included in the Attachment section of this report.
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CARLSBAD
WATERSHED MAP FOR
LA COSTA GREENS
NEIGHBORHOOD 1.11 & 1.13
cmr OF CARLSBAO, CALIFORNIA
La Costa Greens Neighborhood 1.11 & 1.13
storm Water Management Plan
The proposed treatment unit will be located offline from the main storm drain system
and is proposed in the vicinity of the intersection of Goldstone Road and Street GG
in Neighborhood 1.14.
85'*^ percentile runoff will be treated in the storm water BMP's prior to discharge to
the existing storm drain and open channel. Flows in excess ofthe treatment flow will
bypass the treatment units.
A runoff coefficient of 0.56 was assumed for the proposed single-family residential
developments, based on County of San Diego criteria.
1.4 - Results and Recommendations
Using the 85^*^ percentile rainfall of 0.67 inches (see Isopluvial Map in chapter 7) and
assuming approximately 25 percent imperviousness in the contributing watershed
Table 1 below summarizes rational method 85*"^ percentile calculations for the
proposed water quality treatment units for the La Costa Greens Neighborhoods 1.11
and 1.13 developments.
Table 1 - Developed Conditions 85^*^ Percentile Calculations
Treatment
Area
Drainage
Area
(acres)
85'*'
Percentile
Rainfall
(inches)
Rainfall
Intensity
(inches/hour)
Runoff
Coefficient
Neighborhood
1.11 10.6 0.67 0.2 0.53*
Neighborhoods
1.13, 1.14&
1.12 South
76 0.67 0.2 0.4*
*Note; Weighted C coefficients Inclusive of natural watershed.
Rational Method calculations predicted 85'^^ percentile runoff flows of roughly 1.1 cfs
and 6.Icfs discharging to the Neighborhoods 1.11 and 1.13 treatment units
respectively.
Neighborhood 1.11
Prior to discharge into the open channel, storm water from Neighborhood 1.11 will
pass though a proposed diversion structure that will divert the entire 85"^ percentile
flow to a proposed storm water treatment unit. Flows in excess of the treatment flow
will bypass the treatment unit. This analysis indicates that a Vortechs Model 1000
will be required to meet the water quality treatment requirements. The proposed
Vortechs Model 1000 will be located offline from the main storm drain system and is
proposed in the vicinity of Goldstone Road to the South West corner of
Neighborhood 1.11.
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La Costa Greens Neighborhood 1.11 & 1.13
Storm Water Management Plan
Neighborhood 1.13
Prior to discharge into the existing storm drain in Alga Road, storm water from
Neighborhood 1.13 will pass though a proposed diversion structure that will divert
the entire 85'^^ percentile flow to a proposed storm water treatment unit. Flows in
excess of the treatment flow will bypass the treatment unit. This analysis indicates
that a Vortechs Model 7000 will be required to meet the water quality treatment
requirements. The proposed Vortechs Model 7,000 will be located offline from the
main storm drain system near the intersection of Goldstone Road and Street GG.
85'*^ percentile flows will be treated in the proposed Vortechs units prior to
discharging to the open channel orthe existing storm drain in Alga Road.
The proposed Vortechs units are offline precast treatment units. The 85*^ percentile
design flow rate is forced into the treatment area by a diversion weir built in the
upstream junction. Flows in excess of the design flow rate pass over the weir and
proceed downstream.
1.5 - Conclusion
The combination of proposed construction and permanent BMP's will reduce, to the
maximum extent practicable, the expected project pollutants and will not adversely
impact the beneficiai uses of the receiving waters.
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La Costa Greens Neighborhood 1.11 & 1.13
Storm Water Management Plan
CHAPTER 2 - STORM WATER CRITERIA
2.1 - Regional Water Qualitv Control Board Criteria
All runoff conveyed in the proposed storm drain systems will be treated in
compliance with Regional Water Quality Control Board regulations and NPDES
criteria prior to discharging to natural watercourses. California Regional Water
Quality Control Board Order No. 2001-01, dated February 21, 2001, sets waste
discharge requirements for discharges of urban runoff from municipal storm
separate drainage systems draining the watersheds of San Diego County.
Per the RWQCB Order, post-development runoff from a site shall not contain
pollutant loads which cause or contribute to an exceedance of receiving water
quality objectives or which have not been reduced to the maximum extent
practicable. Post-construction Best Management Practices (BMPs), which refer to
specific storm water management techniques that are applied to manage
construction and post-construction site runoff and minimize erosion, include source
control - aimed at reducing the amount of sediment and other pollutants - and
treatment controls that keep soil and other pollutants onsite once they have been
loosened by storm water erosion.
Post construction pollutants are a result ofthe urban development ofthe property
and the effects of automobile use. Runoff from paved surfaces can contain both
sediment (in the form of silt and sand) as well as a variety of pollutants transported
by the sediment. Landscape activities by homeowners are an additional source of
sediment.
All structural BMPs shall be located to infiltrate, filter, or treat the required runoff
volume or flow (based on the 85"^ percentile rainfall) prior to its discharge to any
receiving watercourse supporting beneficial uses.
2.2 - Citv of Carlsbad SUSMP Criteria
Perthe City of Carlsbad SUSMP, the La Costa Greens Neighborhood 1.11 & 1.13
project is classified as a Priority Project and subject to the City's Permanent Storm
Water BMP Requirements. These requirements required the preparation of this
Storm Water Management Plan.
The Storm Water Applicability Checklist, which must be included along with Grading
Plan applications, is included on the following page.
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storm Water Standards
4703/03
APPENDIXA
lv
i
STORM WATER REQUIREMENTS APPUCABILITY CHECKUST
Complete Sections 1 and 2 of the following checklist to determine your project's
permanent and construction storm water best management practices requirements
This fomn must be compieted and submitted with your permit applicaton.
Sectloni. Permanent Storm Water BMP Requirements:
If any answers to Part A are answered "Yes," your project is subject to the "Priority
Project Pemianent Storm Water BMP Requirements," and "Standard Permanent Storm
Water BMP Requirements" in Section III. "Pennanent Storni Water BMP Selection
Procedure" in the Storm Water Standards manual.
If all answers to Part A are "No," and any answers to Part B are "Yes," your project is
only subject to the "Standard Pemianent Stomi Water-BMP Requirements". If every
question in Part A and B is answered "No," your project is exempt from permanent
storm water requirements.
Does the project meet the definition of one or more of the priority project
categories?* Yes No
1. Detached residential development of 10 or more units
2. Attached residential development of 10 or mora units
3. Commen::ial development greater than 100,000 squara feet J
4. Automotiva repair shop
5. Restaurant T 6. steep hillside development greater than 5,000 square feet J 7. Project discharqing to receiving waters within Environmentally Sensitive Areas
a. Parking lots greater than or equal to 5,000 ff or with at least 15 parking spaces, and
potenflallv exposed to urban runoff V
9. Streets, roads, highways, and freeways which would create a new paved surface that is
5,000 square feet or qreater /
* Refer to the definitions section in the Storm Water Standards tor expanded deflnitions of the priority
proiect categories.
Urpited Exdusiom Trenching and resurfacing worit associated with utility projects ara not considered
priority projects. Paridng lots, buildings and otiier structures assodated witii utility projects are
priority projects if one or mora of the criteria In Part A is met If all answers to Part A are "No",
continue to Part B.
30
La Costa Greens Neighborhood 1.11 & 1.13
Storm Water Management Plan
CHAPTER 3 - IDENTIFICATION OF TYPICAL POLLUTANTS
3.1 - Anticipated Pollutants from Proiect Site
The following table details typical anticipated and potential pollutants generated by
various land use types. The La Costa Greens Neighborhoods 1.11 &1.13
developments will consist of detached single-family residence. Thus, the Detached
Residentiai Development categories have been highlighted to clearly illustrate which
general pollutant categories are anticipated from the project area.
General Pollutant Categories
Priority
Project
Categories Sediments Nutrients Heavy Metals Organic Compounds Trash & Debris Oxygen Demanding Substances Oil & Grease Bacteria & Viruses Pesticides 'Devefopment
my-f stiff l|x ;
•;•'.- •• '«#;*•
^^^^
Attached
Residential
Development
X X X pd) p(2) P X
Commercial
Development
>100,000 ft^
pd) p(1) 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 ft^
X X X X X X
Parking Lots p(1) p(1) X X pd) X pd)
streets,
Highways &
Freeways
x pd) X X(4) X p(5) X
Retail Gas
Outiets X X(4) X X
X = anticipated
P = potential
(1) A potential pollutant if landscaping exists on-site.
(2) A potential pollutant ifthe 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.
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La Costa Greens Neighborhood 1.11 & 1.13
storm Water Management Plan
3.2 - Sediment
Soils or other surface 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, smother bottom dwelling organisms, and suppress aquatic
vegetative growth.
3.3 - Nutrients
Inorganic substances, such as nitrogen and phosphorous, that 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.
3.4 - Trash & Debris
Examples include paper, plastic, leaves, grass cuttings, and food waste, which 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 areas where stagnant water is
present, 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.
3.5 - Oxygen-Demanding Substances
Biodegradable organic material as well as chemicals that react with dissolved
oxygen in water to form other 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.
3.6 - Oil & Grease
Characterized as high high-molecular weight organic compounds. Primary sources
of oil and grease are petroleum hydrocarbon products, motor products from leaking
vehicles, oils, waxes, and high-molecular weight fatty acids. Elevated oil and grease
content can decrease the aesthetic value of the water body, as well as the water
quality.
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La Costa Greens Neighborhood 1.11 & 1.13
Storm Water Management Plan
3.7 - Bacteria & Viruses
Bacteria and viruses are ubiquitous microorganisms that thrive under certain
environmental conditions. Tiieir 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, tiie decomposition of excess organic waste
causes increased growth of undesirable organisms in the water.
3.8 - 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 runoff containing toxic levels of its active component.
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La Costa Greens Neighborhood 1.11 & 1.13
Storm Water Management Plan
CHAPTER 4 - CONDITIONS OF CONCERN
4.1 - Receiving Watershed Descriptions
As shown in the watershed map on the following page, the pre-developed La Costa
Greens Neighborhoods 1.11 & 1.13 site drains to an unnamed tributary of San
Marcos Creek which eventually discharges to the Batiquitos Lagoon within the San
Marcos Creek watershed.
Development ofthe site will not cause any diversion to or from the existing
watershed to the storm drain system.
The Regional Water Quality Control Board has identified San Marcos Creek as part
ofthe Carlsbad Hydrologic Unit, San Marcos Creek Watershed, and the Batiquitos
Hydrologic Subarea (basin number 4.51).
4.2 - Pollutants of Concern in Receiving Watersheds
San Marcos Creek is not listed on the EPA's 303(d) List of endangered watenways
(included in this Chapter). Per the "Water Quality Plan for the San Diego Basin", the
beneficial uses for the Batiquitos Lagoon and San Marcos Creek includes
agricultural supply, contact water recreation, non-contact recreation, warm
freshwater habitat, and wildlife habitat.
Table 3-2 from the "Water Quality Plan for the San Diego Basin" (included at the end
of this Chapter) lists water quality objectives for a variety of potential pollutants
required to sustain the beneficial uses ofthe San Marcos hydrologic area.
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CARLSBAD
NEIGHBORHOOD '
cmr OF CARLSBAD, CALIF(»=)N1A
26 Los Monos HSA
(904.31) Agua Hedionda
Lagoon
Bacterial
Indicators^ 6.8 acres 1998
Sedimentation /
Siltation
27 Los Monos HSA
(904.31) Agua Hedionda
Creek lower portion Total Dissolved
Solids lower 7 miles 2002
28 San Marcos HA
(904.50)
Pacific Ocean
Shoreline at Moonlight State Beach Bacterial
Indicators^ 0.4 miles 1998
29 Escondido Creek
HA (904.60)
Pacific Ocean
Shoreline at San Elijo Lagoon Bacterial
Indicators^ 0.44 miles 1998
30 San Elijo HSA
(904.61)
San Elijo
Lagoon
Bacterial
Indicators^ 150 acres 1998
Eutrophic 330 acres
Sedimentation /
Siltation 150 acres
31 San Dieguito HU
(905.00)
Pacific Ocean
Shoreline at San Dieguito Lagoon Mouth Bacterial
Indicators^ 0.86 miles 1998
32 Del Dios HSA
(905.21 and
905.22)
Green Valley
Creek Sulfate 1 mile 2002
33 Del Dios HSA Hodges Entire Reservoir Color Entire 2002
(905.21) Reservoir Entire Reservoir Nitrogen
Phosphorus
Total Dissolved
Solids
Reservoir
(1104 acres)
34 Felicita HSA
(905.23) Felicita Creek Total Dissolved
Solids
lower 0.92
miles 2002
35 Felicita HSA
(905.23) Kit Carson
Creek should in 905.21 HSA Total Dissolved
Solids 1 mile 2002
36 Highland HSA
(905.32) Cloverdale
Creek
Phosphonjs
Total Dissolved
Solids
1.2 miles 2002
37 Sutherland HSA
(905.53)
Sutherland
Reservoir Entire Reservoir Color Entire
Reservoir 2002
38 Miramar Reservoir
HA (906.10)
Los
Penasquitos
Lagoon
Entire Lagoon Sedimentation /
Siltation 469 acres 1998
39 Miramar Reservoir
HA (906.10)
Pacific Ocean
Shoreline
Ton-ey Pines State Beach at Del
Mar (Anderson Canyon)
Bacterial
Indicators^ 0.4 miles 2002
40 Scripps HA
(906.30) Pacific Ocean
La Jolla Shores Beach at El Paseo
Grande Bacterial 3.9 miles 1998 40 Scripps HA
(906.30)
Shoreline La Jolla Shores Beach at Caminito
Del Oro
Indicators^
La Jolla Shores Beach at
Vallecitos
La Jolla Shores Beach at Ave de la
Playa
last updated 9/23/2003
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Table 2-2. BENEFICIAL USES OF INLAND SURFACE WATERS
BENEFICIAL USE
1.2
Inland Surface Waters Hydrologic Unit
Basin Number
M
U
N
A
G
R
1
N
D
P
R
0
C
G
W
R
F
R
S
H
P
0
W
R
E
C
1
R
E
C
2
B
1
0
L
W
A
R
M
C
0
L
D
W
1
L
D
R
A
R
E
S
P
W
N
San Diego County Coastal Streams - continued
• Buena Wsfa Lagoon 4.21 See Coastal Waters- Table 2-3
Buena Vista Creek 4.22 + • • • • • •
Buena Vista Creek 4.21 + • • • • • • •
Agua Hedionda 4.31 See Coastal Waters-Table 2-3
Agua Hedionda Creek 4.32 • • • • • • •
Buena Creek 4.32 • • • • • • •
Agua Hedionda Creek 4.31 • • • • • • •
Letterbox canyon 4.31 • • • • • • •
Canyon de las Endnas 4.40 + 0 • • •
San Marcos Creek Watershed
Batiquitos Lagoon 4.51 See Coastal Waters- Table 2-3
San Marcos Creek 4.52 + • • • • •
unnamed Intermittent streams 4.53 + • • • • •
San Marcos Creek Watershed
San Marcos Creek 4.51 + • • • • •
Encinitas Creek 4.51 + • • • • •
• Existing Beneficial Use
0 Potential Beneficial Use
+ Excepted From MUN (See Text)
1 Waterbodies are listed multiple times if they cross hydrologic area or sub area boundaries.
Benefidal use designations apply to all tributaries to the indicated waterbody, if not listed separately.
Tabl9 2-2
BENEFICIAL USES 2-27
March 12, 1997
Table 2-3. BENEFICIAL USES OF COASTAL WATERS
BENEFICIAL USE
Coastal Waters Hydrologic
Unit Basin
1
N
N
A
R
E
R
E
C
.0
B
1
E
S
W
1
R
A
M
A
A
Q
M
1
S
P
W
A
S
H
Hydrologic
Unit Basin D V C C M 0 T L R R U G w R E Number V
1 2 M L D E A R N M L
L
Pacific Ocean • • • • • • • • • • • • •
Dana Point Harbor • • • • • • • • • •
Del Mar Boat Basin • • • • • • • • • • •
Mission Bay • • • • • • • • • • •
Oceanside Harbor • • • • • • • • • • •
San Diego Bay ^ • • • • • • • • • • • • •
Coastal Lagoons
Tijuana River Estuary ii.ii • • • • • • • • • • •
Mouth of San Diego River 7.11 • • • • • • • • • •
2
Los Penasquitos Lagoon 6.10 • • • • • • • • • •
San Dieguito Lagoon 5.11 • • • • • • • • •
Batiquitos Lagoon 4.51 • • • • • • • • •
San Elijo Lagoon . 5.61 • • • • • • • • •
Aqua Hedionda Lagoon 4.31 • • • • • • • • • •
^ Includes the tidal prisms of the Otay and Sweetwater Rivers.
2 Fishing from shore or boat permitted, but other water contact recreational (REC-1) uses are prohibited.
9 Existing Beneficial Use
Table 2-3
BENEFICIAL USES 2-47
March 12, 1997
Table 3-3. WATER QUALITY OBJECTIVES
Concentrations not to be exceeded more than 10% of the time during any one year period.
Ground Water
Buena Vista Creek HA
Hydrologic
Basin Unit
Number
4.20
Constituent (mg/L or as noted)
TDS Cl SO4 %Na NO3 Fe Mn MBAS ODOR Turb
NTU
Color
Units
El Salto HSA a 4.21 3500 800 500 60 45 0.3 0.05 0.5 2.0 15 1.0
Vista HSA a 4.22 1000 b 400 b 500 b 60 10 b 0.3 b 0.05 b 0.5 0.75 b none 15
15"
1.0
1.0 Agua Hedionda HA a 4.30 1200 500 500 60 10 0.3 0.05 0.5 0.75
Los Monos HSA aj 4.31 3500 800 500 60 45 0.3 0.05 0.5 2.0
2.0 b
none 15
15
1.0
1.0 Encinas HA a 4.40 3500 b 800 b 500 b 60 45 b 0.3 b 0.05 b 0.5 none
San Marcos HA ae 4.50 1000 400 500 60 10 0.3 0.05 0.5 0.75 none 15
Ti"
1.0
7!o~
Batiquitos HSA oek 4.51 3500 800 500 60 45 0.3 0.05 0.5 2.0 none
Escondido Creek HA a 4.60 750 300 300 60 10 0.3 0.05 0.5 0.75 none 15 1.0
T!o" San Elijo HSA a 4.61 2800 700 600 60 45 0.3 0.05 0.5 1.0
Escondido HSA 4.62 1000 300 400 60 10 0.3 0.05 0.5 0.75 none 15
SAN DIEGUITO HYDROLOGIC UNIT 905.00
1.0
Solana Beach HA a
Hodges HA
5,10
5.20
1500 b
1000 b
500 b
400 b
500 b
500 b
60
60
45 b
10 b
0.85 b
0.3 b
0.15 b
0.05 b
0.5
0.5
0.75 b
0.75 b
0.75 b
none 15
15
1.0
1.0
San Pasqual HA 5.30 1000 b 400 b 500 b 60 10 b 0.3 b 0.05 b 0.5 none
Santa Maria Valley HA 5.40 1000 400 500 60 10 0.3 0.05 0.5 0.75 none
5
5
15
15
Santa Ysabel HA 5.50 500 250 250 60 0.3 0.05 0.5 0.75 none 15
1.0
1.0
1.0
PENASQUITOS HYDROLOGIC UNIT 906.00
Miramar Reservoir HA af
Poway HA
6.10
6.20
1200
750 q
500
300
500
300
60
60
10
10
0.3
0.3
0.05
0.05
0.5
0.5
0.75
0.75
none 15
15
1.0
1.0
Scripps HA 6.30
Miramar HA g 6.40 750 300 300 60 10 0.3 0.05 0.5 0.75 none 15 1.0
Tecolote HA 6.50
HA • Hydrologic Araa
HSA - Hydrologic Sub Area (Lower casa letters Indicats endnotes following the table.)
Table 3-3
WATER QUAUTY OBJECTIVES Page 3-29 October 13, 1994
La Costa Greens Neighborhood 1.11 & 1.13
Storm Water Management Plan
Chapter 5 - FLOW-BASED BMPs
5.1 - Design Criteria
Flow-based BMPs shall be designed to mitigate the maximum flowrate of runoff
produced from a rainfall intensity of 0.2 inch per hour. Such basins utilize either
mechanical devices (such as vaults that produce vortex effects) or non-mechanical
devices (based on weir hydraulics and specially designed filters) to promote settling
and removal of pollutants from the runoff.
Per the request of the City of Carlsbad, 85'^^ percentile flow calculations were
performed using the Rational Method. The basic Rational Method runoff procedure
is as follows:
Design flow (Q) = C * I * A
Runoff Coefficient (C) - In accordance with the County of San Diego standards, the
weighted runoff coefficient for all the areas draining to the treatment unit was
determined using the areas analyzed in the final engineering hydrology report. The
runoff coefficient is based on the following characteristics ofthe watershed:
Land Use - Single Family Residential in Developed Areas
Soil Type - Hydrologic soil group D was assumed for all areas. Group D
soils have very slow infiltration rates when thoroughly wetted. Consisting
chiefly of clay soils with a high swelling potential, soils with a high
permanent water table, soils with clay pan or clay layer at or near the
surface, and shallow soils over nearly impervious materials, Group D soils
have a very slow rate of water transmission.
Rainfall Intensity (I) - Regional Water Quality Control Board regulations and NPDES
criteria have established that flow-based BMPs shall be designed to mitigate a
rainfall intensity of 0.2 inch per hour.
Watershed Area (A) - Corresponds to total area draining to treatment unit.
5.2 - Vortechs Treatment Units
The Vortechs Storm Water Treatment System is designed to efficiently remove grit,
contaminated sediments, metals, hydrocarbons and floating contaminants from
surface runoff. Combining swirl-concentrator and flow-control technologies to
eliminate turbulence within the system, the Vortechs System ensures the effective
capture of sediment and oils and prevents resuspension of trapped pollutants for
flows up to 25 cfs.
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Storm Water Management Plan
Other features of the Vortechs Systems include the following:
- Large capacity system provides an 80 percent net annual Total
Suspended Solids (TSS) removal rate
- Unit is installed below grade
Low pump-out volume and one-point access reduce maintenance costs
- Design prevents oils and other floatables from escaping the system during
cleanout
Enhanced removal efficiencies of nutrients and heavy metals with offline
configuration
The tangential inlet to the system creates a swirling motion that directs settleable
solids into a pile towards the center of the grit chamber. Sediment is caught in the
swirling flow path and settles back onto the pile after the storm event is over.
Floatable entrapment is achieved by sizing the low flow control to create a rise in the
water level of the vault that is sufficient to just submerge the inlet pipe with the SS'*^
percentile flow.
5.3 - Pollutant Removal Efficiencv Table
Pollutant of Concern BMP Categories
Hydrodynamic
Separation
Devices'^'
Vortechs'"
Stonnwater
Treatment System
Sediment M-H H
Nutrients L-M L-M
Heavy Metals L-M L-M
Organic Compounds L-M L-M
Trash & Debris M-H H
Oxygen Demanding Substances L L
Bacteria L L
Oil & Grease L-H H
Pesticides L L
(1) The County will periodically assess the performance characteristics ofthese BMPs to
update this table.
(2) Proprietary Structural BMPs. Not all serve the same function.
L (Low): Low removal efficiency (roughly 0-25%)
M (Medium): Medium removal efficiency (roughly 25-75%)
H (High): High removal efficiency (roughly 75-100%)
U: Unknown removal efficiency, applicant must provide evidence supporting use
Sources: Guidance Specifying Management Measures for Sources of Nonpoint Pollution in
Coastal Waters (1993), National Stonnwater Best Management Practices Database (2001),
and Guide for BMP Selection in Urban Developed Areas (2001).
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La Costa Greens Neighborhood 1.11 & 1.13
Storm Water Management Plan
5.4 - Maintenance Reguirements
Flow-based storm water treatment devices should be inspected periodically to
assure their condition to treat anticipated runoff. Maintenance ofthe proposed
Vortechnics units includes inspection and maintenance 1 to 4 times per year.
Maintenance ofthe Vortechs units involves the use of a "vactor truck", which clears
the grit chamber of the treatment unit by vacuuming all the grit, oil and grease, and
water from the sump. Typically a 3-man crew is required to perform the
maintenance ofthe treatment unit. Properly maintained Vortechs Systems will only
require evacuation of the grit chamber portion of the system. In some cases, it may
be necessary to pump out all chambers. In the event of cleaning other chambers, it
is imperative that the grit chamber be drained first.
Proper inspection includes a visual observation to ascertain whether the unit is
functioning properly and measuring the amount of deposition in the unit. Floatables
should be removed and sumps cleaned when the sump storage exceeds 85 percent
of capacity specifically, or when the sediment depth has accumulated within 6 inches
of the dry-weather water level. The rate at which the system collects pollutants will
depend more heavily on site activities than the size ofthe unit.
5.5 - Schedule of IVlaintenance Activities
Vortechs Model 1000
Target Maintenance Date - March 15'^^
Maintenance Activity - Annual inspection and cleanout. Clear grit chamber of each
unit with vactor truck. Perform visual inspection. Remove floatables.
Vortechs Model 7000
Target Maintenance Date - March 15'^
Maintenance Activity - Annual inspection and cleanout. Clear grit chamber of each
unit with vactor truck. Perform visual inspection. Remove floatables.
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Storm Water Management Plan
5.6 - Annual Operations & Maintenance Costs
The following costs are intended only to provide a magnitude of the costs involved in
maintaining BMPs. Funding shall be provided by the Master Home Owners
Association for La Costa Greens, of which Neighborhoods 1.11 & 1.13 are members
of.
Approximate annual maintenance costs for each ofthe proposed Vortechs units are
outlined below. Costs assume a 3 man crew:
Maintenance for Model 1000:
Periodic Inspection, Maintenance and Monitoring = $800
Annual Cleanout Cost = $500
Maintenance for Model 7000:
Periodic Inspection, Maintenance and Monitoring = $800
Annual Cleanout Cost = $2,500
Subtotal = $4,600
Contingency = $460
Total = $5,060
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La Costa Greens Neighborhood 1.11 & 1.13
Storm Water Management Plan
CHAPTER 6 - SOURCE CONTROL BMPS
6.1 - Landscaping
Manufactured slopes shall be landscaped with suitable ground cover or installed with
an erosion control system. Homeowners will be educated as to the proper routine
maintenance to landscaped areas including trimming, pruning, weeding, mowing,
replacement or substitution of vegetation in ornamental and required landscapes.
Per the RWQCB Order, the following landscaping activities are deemed unlawful
and are thus prohibited:
Discharges of sediment
Discharges of pet waste
Discharges of vegetative clippings
- Discharges of other landscaping or construction-related wastes.
6.2 - Urban Housekeeping
Fertilizer applied by homeowners, in addition to organic matter such as leaves and
lawn clippings, all result in nutrients in storm water runoff. Consumer use of
excessive herbicide or pesticide contributes toxic chemicals to runoff. Homeowners
should be educated as to the proper application of fertilizers and herbicides to lawns
and gardens.
The average household contains a wide variety of toxins such as oil/grease,
antifreeze, paint, household cleaners and solvents. Homeowners should be
educated as to the proper use, storage, and disposal ofthese potential storm water
runoff contaminants.
Per the RWQCB Order, the following housekeeping activities are deemed unlawful
and are thus prohibited:
Discharges of wash water from the cleaning or hosing of impervious
surfaces including parking jots, streets, sidewalks, driveways, patios,
plazas, and outdoor eating and drinking areas (landscape irrigation and
lawn watering, as well as non-commercial washing of vehicles in
residential zones, is exempt from this restriction)
Discharges of pool or fountain water containing chloride, biocides, or other
chemicals
Discharges or runoff from material storage areas containing chemicals,
fuels, grease, oil, or other hazardous materials
Discharges of food-related wastes (grease, food processing, trash bin
wash water, etc.).
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La Costa Greens Neighborhood 1.11 & 1.13
Storm Water Management Plan
6.3 - Automobile Use
Urban pollutants resulting from automobile use include oil, grease, antifreeze,
hydraulic fluids, copper from brakes, and various fuels. Homeowners should be
educated as to the proper use, storage, and disposal ofthese potential storm water
contaminants.
Per the RWQCB Order, the following automobile use activities are deemed unlawful
and are thus prohibited:
Discharges of wash water from the hosing or cleaning of gas stations,
auto repair garages, or other types of automotive service facilities.
Discharges resulting from the cleaning, repair, or maintenance of any type
of equipment, machinery, or facility including motor vehicles, cement-
related equipment, port-a-potty servicing, etc.
Discharges of wash water from mobile operations such as mobile
automobile washing, steam cleaning, power washing, and carpet
cleaning.
The Homeowners Association will make all homeowners aware of the
aforementioned RWQCB regulations through a homeowners' education program. A
monitoring program should also be implemented to insure compliance.
6.4 - Site Design BMPs
Priority projects, such as the La Costa Greens Neighborhood 1.11 & 1.13
developments, shall be designed to minimize, to the maximum extent practicable the
introduction of pollutants and conditions of concern that may result in significant
impact, generated from site runoff to the storm water conveyance system. Site
design components can significantly reduce the impact of a project on the
environment. The following design techniques have been proposed to accomplish
this goal.
- Implementing on-lot hydrologically functional landscape design and
management practices; Additional detail regarding landscaping design is
discussed in section 6.1.
- Minimizing project's impervious footprint. Methods of accomplishing this goal
include constructing streets, sidewalks, and parking lots to the minimum
widths necessary without compromising public safety. Another method for
minimizing impervious area includes incorporating landscaped areas in the
drainage system to encourage infiltration and reduce the amount of directly
connected impen/ious areas.
- Minimizing directly connected Impervious Areas. Where landscaping is
proposed, drain rooftops into adjacent landscaping prior to discharging to the
storm water conveyance system.
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La Costa Greens Neighborhood 1.11 & 1.13
Storm Water Management Plan
CHAPTER 7 - SITE BMP DESIGN
VORTECHS TREATMENT UNITS
7.1 - BMP Locations
The site design includes two (2) Vortechs treatment units (shown on BMP Location
Maps located on the following page). The proposed treatment units will located
offline from the main storm drain system, in the vicinity of Goldstone Road to the
South West corner of Neighborhood 1.11 and also in the vicinity ofthe intersection
of Goldstone Road and Street GG in Neighborhood 1.14.
7.2 - Determination of Design Treatment Flows
The 85*^ percentile design flow rate has been calculated using the Rational Method.
Required data for the Rational Method treatment flow determination include the
following:
- Runoff Coefficient (C)
Rainfall Intensity (I) = 0.20 inches per hour
Drainage area to treatment unit (A)
Runoff coefficients were derived based upon a weighted average of each area
tributary to the treatment unit and the associated runoff coefficient.
The following table summarizes the parameters used for determination of design
flows to each of the Vortechs treatment units.
DESIGN RUNOFF DETERMINATION SUMMARY TABLE
Treatment Unit
Runoff
Coefficient
(C)
85^"
Percentile
Rainfall
(inches/hour)
Drainage
Area
(acres)
85'^ Pet.
Design Flow
(cfs)
Vortechs 1000 0.53* 0.2 10.6 1.1
Vortechs 7000 0.4* 0.2 76 6.1
*Note: Weighted C coefficients inclusive of natural watershed.
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La Costa Greens Neighborhood 1.11 & 1.13
Storm Water Management Plan
7.3 - Vortechs Treatment Unit Selection
The proposed Vortechs units are offline precast treatment units. The 85"^ percentile
design flow rate is forced into the treatment area by a diversion weir built in the
upstream junction. Flows in excess ofthe design flow rate pass over the weir and
proceed downstream.
The following table shows the treatment capacities of the proposed Vortechs units.
VORTECHS UNIT TREATMENT CAPACITY TABLE
Treatment Unit
85'" Pet.
Design Flow
(cfs)
Recommended
Vortechs
Model
Treatment Capacity
(efs)
Model 1000 1.1 1000 1.6
Model 7000 6.1 7000 11.0
The Vortechs Model 1000, with a peak treatment flow design capacity of 1.6 cfs, was
selected because of the results of the Low Flow Diversion spreadsheet, included in
the Attachments section ofthis report, show that during the 100-yr storm the
diversion weir would divert 1.5 cfs through the treatment unit. Therefore the unit has
been sized to handle tire flow of 1.5 cfs.
The Vortechs Model 7000, with a peak treatment flow design capacity of 11.0 cfs,
was selected because of the results of the Low Flow Diversion spreadsheet,
included in the Attachments section ofthis report, show that during the 100-yr storm
the diversion weir would divert 10.9 cfs through the treatment unit. Therefore the
unit has been sized to handle the flow of 10.9 cfs.
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VILLAGES OF U\ COSTA
NEIGHBORHODD 1.13, 1.14, AND PORTIONS OF 1.12 (SOUTH)
TREATMENT FLOW DETERMINATION:
Q=C*I*A
TREATMENT AREA 75.92 ACRES
RAINFALL INTENSITY 0.20 IN/HR
WEIGHTED CURVE NUMBER 0.40
Q = 6.07 CFS
1:00 PM8/15/2003 Sheetl RM-TREATMENT FLOW-12-13-14.xls
La Costa Greens Neighborhoods 1.12,1.13, and 1.14
HYDRAULIC ANALYSIS OF LOW FLOW DIVERSION & VORTECHS UNIT AT CLEANOUT
LOW FLOW ORIFICE (Q = 6.07 cfs)
Weir Formula for Orifices & Short Tubes (free & submerged)
Q= Ca(2gh)" (Eqn. 1)
Q= Ca(64.32h)''-^; C=0.56
Q = 4.491 a(h)°'^, where a = area of orifice opening,
h = head (ft) above centeriine of orifice
OnficeSize, L= 16 in. ,a= 1.33 sq.ft., invert elevation = 100.00 ft.
H = 12 in.
HIGH FLOW(Qioo= 130.7 cfs)
Weir Formula for Bypass Weir & Vortechs Weir
Q = CLH'C = 3.3 for Bypass
6.2 for Vortechs
(Eqn. 2)
Bypass: L = 10.0 ft. @ elevation 101.50 ft. ( 1.50 ft.)
Vortechs L = 1.0 fL @ elevation 105.00 ft.
Lo Flow (Eq. 1) Weir Flow (Eq. 2) LoFiow(Eq. 1) Weir Flow (Eq. 2)
ELEV. Onfice Vortechs Bypass TOTAL ELEV. Orifice Vortechs Bypass TOTAL
(feet) h(ft) Q(cfs) H(ft) Q(cfs) H(ft) Q(cfe) Q(cfs) (feet) h(ft) Q(cfs) H(ft) Q (cfs) H(ft) Q(cfs) Q(cfe)
100.00 0.0 0.0 0.0 0.0 0.0 0.00 0.0 102.58 2.08 8.64 0.00 0.00 1.08 37.2 45.9
100.17 0.00 0.00 0.00 0.00 0.00 0.00 0.00 102.67 2.17 8.81 0.00 0.00 1.17 41.6 50.4
100.25 0.00 0.00 0.00 0.00 0.00 0.00 0.00 102.75 2.25 8.98 0.00 0.00 1.25 46.1 55.1
100.33 0.00 0.00 0.00 0.00 0.00 0.00 0.00 102.83 2.33 9.15 0.00 0.00 1.33 50.8 60.0
100.42 . 0.00 0.00 0.00 0.00 0.00 0.00 0.00 102.92 2.42 9.31 0.00 0.00 1.42 55.6 65.0
100.50 .0.00 0.00 0.00 0.00 0.00 0.00 0.00 103.00 2.50 9.47 0.00 0.00 1.50 60.6 70.1
100.58 0.08 1.73 0.00 0.00 0.00 0.00 1.73 103.08 2.58 9.62 0.00 0.00 1.58 65.7 75.4
100.67 0.17 2.44 0.00 O.OO" 0.00 0.00 2.44 103.17 2.67 9.78 0.00 0.00 1.67 71.0 80.8
100.75 0.25 2.99 0.00 0.00 0.00 0.00 2.99 103.25 2.75 9.93 0.00 0.00 1.75 76.4 86.3
100.83 0.33 3.46 0.00 0.00 0.00 0.00 3.46 103.33 2.83 1008 0.00 0.00 1.83 81.9 92.0
100.92 0.42 3.87 0.00 0.00 0.00 0.00 3.87 103.42 2.92 10.23 0.00 0.00 1.92 87.6 97.8
101.00 0.50 4.23 0.00 0.00 0.00 0.00 4.23 103.50 3.00 10.37 0.00 0.00 2.00 93.3 103.7
101.08 0.58 4.57 0.00 0.00 0.00 0.00 4.57 103.58 3.08 10.52 0.00 0.00 2.08 99.2 1097
101.17 0.67 4.89 0.00 0.00 0.00 0.00 4.89 103.67 3.17 1066 0.00 0.00 2.17 105.2 115.9
101.25 0.75 5.19 0.00 0.00 0.00 0.00 5.19 103.75 3.25 10.80 0.00 0.00 2.25 111.4 122.2
101.33 0.83 5.47 0.00 0.00 0.00 0.00 5.47 t03 83 3 33 1093 OQO 0 30 2 33 1176 128 6 Q\-io:
101.42 0.92 5.73 0.00 0.00 0.00 0.00 5.73 103 92 3 42 , t1.07 coc : 30 2.42 .124 0 135 0 ^
" 10T.5Q . .5-99.. aod'. " 5.'99 Z 104.00 3.50 11.20 0.00 0.00 2.50 130.4 141.6
101.58 1.08 6.23 0.00 0.00 0.08 0.79 7.03 104.08 3.58 11.34 0.00 0.00 2.58 137.0 148.4 Cft
101.67 1.17 6.47 0.00 0.00 0.17 2.25 8.71 104.17 3.67 11.47 0.00 0.00 2.67 143.7 155.2
101.75 1.25 6.70 0.00 0.00 0.25 4.13 10.82 104.25 3.75 11.60 0.00 0.00 2.75 150.5 162.1
101.83 1.33 6.91 0.00 0.00 0.33 6.35 13.27 104.33 3.83 11.72 0.00 0.00 2.83 157.4 169.1
101.92 1.42 7.13 0.00 0.00 0.42 8.88 16.00 104.42 3.92 11.85 0.00 0.00 2.92 164.4 176.2
102.00 1.50 7.33 0.00 0.00 0.50 11.67 19.00 104.50 4.00 11.98 0.00 0.00 3.00 171.5 183.4
102.08 1.58 7.54 0.00 0.00 0.58 14.70 22.24 104.58 4.08 12.10 0.00 0.00 3.08 178.7 190.8
102.17 1.67 7.73 0.00 0.00 0.67 17.96 25.69 104.67 4.17 12.22 0.00 0.00 3.17 186.0 198.2
102.25 1.75 7.92 0.00 0.00 0.75 21.43 29.36 104.75 4.25 12.35 0.00 0.00 3.25 193.3 205.7
102.33 1.83 8.11 0.00 0.00 0.83 25.10 33.21 104.83 4.33 12.47 0.00 0.00 3.33 200.8 213.3
102.42 1.92 8.29 0.00 0.00 0.92 28.96 37.25 104.92 4.42 12.58 0.00 0.00 3.42 208.4 221.0
102.50 2.00 8.47 0.00 0.00 1.00 33.00 41.47 105.00 4.50 12.70 0.00 0.00 3.50 216.1 228.8
so USE MODEL 7000
vortschsl 2inctwTn<02jds
VILLAGES OF LA COSTA
NEIGHBORHOOD 1.11
TRE.ATMENT FLOW DETE.RM!MAT!ON:
Q=C*I*A
TREATMENT AREA 10.60 ACRES
RAINFALL INTENSITY 0.20 IN/HR
WEIGHTED CURVE NUMBER 0.53
Q= 1.12 CFS
11:32 AM8/15/2003 Sheetl RM-TREATMENT FLOW.xIs
La Costa Greens Neighborhood 1.11
HYDRAULIC ANALYSIS OF LOW FLOW DIVERSION & VORTECHS UNIT AT CLEANOUT (Node #)
LOW FLOW ORIFICE (Q = 1.12 cfs)
Weir Formula for Orifices & Short Tubes (free & submerged)
O •
Q =
Orifice Size, L =
H =
\—a- -y
Ca(64.32h)' 0.5.
IC,., ^ \
\.-..\ii. 11
C = 0.56
4.491 a(h)°^ where
in.,
in.
0.21
a = area of orifice opening,
h = head (ft) above centeriine of orifice
sq.ft., invert elevation = 100.00 ft.
HIGH FLOW (Qso = 14.4 cfs)
Weir Formula for Bypass Weir & Vortechs Weir
Q = CLH'-^; C = 3.3
6.2
for Bypass
for Vortechs
(Eqn. 2)
Bypass: L = 4.0 ft. @ elevation 101.75 ft. ( 1.75 ft.)
Vortechs L = 1.0 ft. @ elevation 102.58 ft.
LoFlow(Eq. 1) Weir Flow (Eq. 2) Lo Fiow(Eq. 1) Weir Flow (Eq. 2)
ELEV. Orifice Vortechs Bypass TOTAL ELEV. Orifice Vortechs Bypass TOTAL
(feet) h(ft) Q (cfs) H(ft) Q(cfs) H(ft) Q (cfs) Q(cfs) (feet) h(ft) Q(cfs) H(ft) Q (cfs) H(ft) Q (cfs) Q(cfs)
100.00 0.0 0.0 0.0 0.0 0.0 0.00 0.0 102.58 2.37 1.44 0.00 0.00 0.83 10.0 11.5
100.17 0.00 0.00 0.00 0.00 0.00 0.00 0.00 102.67 2.46 1.47 0.08 0.15 0.92 11.6 13.2
100.25 0.00 0.00 0.00 0.00 0.00 0.00 0.00 .102 75 2.54 M3 0-171 0 42 Vt.oo-132 ri5i
100.33 0.13 0.33 0.00 0.00 0.00 0.00 0.33 102.83 2.62 1.52 0.25 0.78 1.08 14.9 17.2
100.42 0.21 0.43 0.00 0.00 0.00 0.00 0.43 102.92 2.71 1.54 0.33 1.19 1.17 16.6 19.4
100.50 0.29 0.51 0.00 0.00 ooo 0.00 0.51 103.00 2.79 1.56 0.42 1.67 1.25 18.4 21.7
100.58 0.38 0.57 0.00 0.00 0.00 0.00 0.57 103.08 2.87 1.59 0.50 2.19 1.33 20.3 24.1
100.67 0.46 0.63 0.00 0.00 -0.00 0.00 0.63 103.17 2.96 1.61 0.58 2.76 1.42 22.3 26.6
100.75 0.54 0.69 0.00 0.00 0.00 0.00 0.69 103.25 3.04 1.63 0.67 3.38 1.50 24.2 29.3
100.83 0.63 0.74 0.00 0.00 0.00 0.00 0.74 103.33 3.12 1.65 0.75 4.03 1.58 26.3 32.0
100.92 0.71 0.79 0.00 0.00 0.00 0.00 0.79 103.42 3.21 1.68 0.83 4.72 1.67 28.4 34.8
101.00 0.79 0.83 0.00 0.00 0.00 0.00 0.83 103.50 3.29 1.70 0.92 5.44 1.75 30.6 37.7
101.08 088 0.88 0.00 0.00 0.00 0.00 0.88 103.58 3.37 1.72 1.00 6.20 1.83 32.8 40.7
101.17 0.96 0.92 0.00 0.00 0.00 0.00 0.92 103.67 3.46 1.74 1.08 6.99 1.92 35.0 43.8
101.25 1.04 0.95 0.00 0.00 0.00 0.00 0.95 103.75 3.54 1.76 1.17 7.82 2.00 37.3 46.9
101.33 1.13 0.99 0.00 0.00 0.00 0.00 0.99 103.83 3.62 1.78 1.25 8.67 2.08 39.7 50.1
101.42 1.21 1.03 0.00 0.00 0.00 0.00 1.03 103.92 3.71 1.80 1.33 9.55 2.17 42.1 53.4
101.50 1.29 1.06 0.00 0.00 0.00 0.00 1.06 104.00 3.79 1.82 1.42 10.46 2.25 44.5 56.8
101.58 1.38 1.10 0.00 0.00 0.00 0.00 1.10 104.08 3.87 1.84 1.50 11.39 2.33 47.0 60.3
101.67 1.46 1.13 0.00 0.00 0.00 0.00 1.13 104.17 3.96 1.86 1.53 12.36 2.42 49.6 63.8
101 75 1 54 1 16 OQO 0 00 0 00 0 00 116| 104.25 4.04 1.88 1.67 13.34 2.50 52.2 67.4
101.83 1.63 1.19 0.00 0.00 0.08 0.32 1.51 104.33 4.12 1.90 1.75 14.36 2.58 54.8 71.1
101.92 1.71 1.22 0.00 0.00 0.17 0.90 2.12 104.42 4.21 1.92 1.83 15.39 2.67 57.5 74.8
102.00 1.79 1.25 0.00 0.00 0.25 1.65 2.90 104.50 4.29 1.94 1.92 16.46 2.75 60.2 78.6
102.08 1.88 1.28 0.00 0.00 0.33 2.54 3.82 104.58 4.37 1.96 2.00 17.54 2.83 63.0 82.5
102.17 1.96 1.31 0.00 0.00 0.42 3.55 4.86 104.67 4.46 1.98 2.08 18.65 2.92 65.8 86.4
102.25 2.04 1.34 0.00 0.00 0.50 4.67 6.00 104.75 4.54 1.99 2.17 19.73 3.00 68.6 90.4
102.33 2.13 1.36 0.00 0.00 0.58 5.88 7.24 104.83 4.62 2.01 2.25 20.93 3.08 71.5 94.4
102.42 2.21 1.39 0.00 0.00 0.67 7.19 8.58 104.92 4.71 2.03 2.33 22.10 3.17 74.4 98.5
102.50 2.29 1.42 0.00 0.00 0.75 8.57 g.gg 105.00 4.79 2.05 2.42 23.30 3.25 77.3 102.7
so USE MODEL 1000
vortechsSinch-rTn*01 jds
APPROXIMATE VORTECHNICS TREATMENT
AREAS
i .1:
Lil:.-''/'r- v.: ' ^ • \
ISiil
Model 1000 1.6 10 14 15 18 23
Model 2000 2.8 17 24 26 31 39
Model 3000 4.5 27 38 41 49 62
Model 4000 6.0 37 51 55 66 83
Model 5000 8.5 52 72 78 94 117
Model 7000 11.0 73 102 110 132 165
Model 9000 14.0 93 129 140 168 210
Model 11.000 17.5 117 162 175 210 263
Model 16,000 25.0 167 231 250 300 375
It
^^^^
itiittii!
'imtMi^Si
Plan View
• . I » •' Grifi(3iamfaep Ol Chamber/. FlowCantrol - . Baffle Walt: . • Chamber
•f";••••; Bavatioii.View: Dry-Weather
Grit Chamber
The swirling mation created by tha
tangential inlet directs setlleable
solids ta:ward the center of this
• chamber. Sediment is caught in . .:
the swiriing flow path arid settles" "' :
back onto the pile after the storm ' '\
• event is over. - • - .i
Oil Chamber & Baffle Wdi''" '
The center baffle traps floatables in • 'J
. -the oil chamber, even during cleari- •'••^l
..'.o'Jt. Highly resistant to flow.surges. ••}.
- Flo-w Contrdl Cboraber •^.^vi ii^'^
; .....The weir and oriflca flow cantrbls^^'j' •.-. t
Raise level, and voiurne in. the. J
• systern as flow rate increas'es;' and':''^1
• 2J gradually drain the.'system.'as"".-^'
•'-. flow rata subsides.' J.... "; ;,. -.^ i.-jj'. I
1) Initial Wet Weather Phase
During a two-morrth stotm event tha water level begins to
rise above the top of the inlet pipe. This influent control
feature reduces turbulerca and avoids resuspension
of pollutants.
3) FuU Capacity Phase
When the high-flow outlet approaches full discharge, storm
drains ars flcwirg st peak capacity Tha Vortechs Systam is
designed to match yoir design storm flow and provide Creat-
2) Trtmsition Phase
As the inflow rate increases above the controlled outflow
rata, the tank fills and the floating contaminant layer accu-
mulated from past storms rises. Swiriing action increases
at this stage, while sediment pile remains stable.
4) Storm Snbsidanca Phase/Cleaning
Treated runoff is decanted at a contralled rate, restoring the
water level to a low dryweather vdume and revealing a cnnicai
pile of sediment The law water level facHitatBS insoection and
Stormwater Treatment System
Plan View
Perfqratad Covers,
J L
'enorataa covers
INV.i
3ta4t
6" ta 9'
Typical
=1 /
Seal
Bevation View
To begin the design of your
Vortechs System, refer to the
sizing chart below and com-
plete a Specifier's Worksheet to
provide details about your site
and design fLo-ws. Then simply
fax or mcdl the -worksheet to
Vortechnics -mth your site plan,
and -we'll produce detailed
Vortechs System scale draw-
ings free of charge.
•fii'.i^lQCO }•• -.,
••.'5/20 •
^;g^:76SQv-$-
,••.• 3/7 .•
v4/13
•.. B/aa
-.•.••..7/38
.8/50
J;V:-;\»;g/B4;.. -.
•••l^.^Q/7^
2.8
4.5
6.Q
8.5
11..Q
14.0
17.5
25.0:..
1.25
1.75-.- • ••
2.5 .•
3.25
4.Q'.;.-
4.75...-.'
.5..5:.-::
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l4jcS
:i•.•!;. ..•.-.•.•.-: Engineering Notas-'' ..• '';..•]; .•.\' ;•_'
A] ftir iivlfim >A3rtaeh3 Systama without a bypass,-scdng criteria is basad an prtwiding'ana square foot of grit-
ehamharsurfaca araa fop aach TOO gpm of paak design storm (low rata (B.g., IChyaar storm]. For mora -V :
.details aboue Vbrtadwica sizmg-erttaria referto \&rt8iiira^ • • • • "•.•:'.'•.':
. aJSadrnane storage voliirTp asaumas »3 (boe sump..- • : - • I .-•.v .. i ..
- CJ- Conaenjctlon details may-varv depending a'n""thB bpeclflo appllcatian. Any altaratlons lo the sizing chare speciS-
. sstiona WiH appeap on yortachnic5_tfim.ensiQnal and shop drawings. Plaasa-call Vortedinics far tha weight of spa--
•'.dlIc'>Airt8chasyatamairnaadad.. •. ..'•.'..'•'.• " .' i'
Spacial Notai Cl stcraga eapade^.vwhan it ia needed tn,,maat'a apaciflc-fequpamene for spiH containmant, can ba .
•' sized CO maee cha storaga raquirflraBniriAiillr ttia selected model. Vtartachnics tachnical staff will optimiza systam' '
geometry co.maae containmane raquiramehia wilhin a corracdy sized Vbrtachs System-. '.•-.•'.
'.•MeirhSpaciHistiim'aai^
Vortechs System Inlet/Outlet Configurations
Vortechs Systems can be configured to accommo-
date various inlet and ouflet pipe orientations. m
The inlet pipe can enter the end or side of the
tank at right angles - outlet pipes can exit the end
or the side of system at most angles.
End Inlet \ Side Inlet
To Palish
t 1 nfflino 1 I To
La Costa Greens Neighborhood 1.11 & 1.13
Storm Water Management Plan
CHAPTER 8 - REFERENCES
"Standard Urban Storm Water Mitigation Plan - Storm Water Standards", City of
Carlsbad, April 2003.
"Standards for Design and Construction of Public Worl<s Improvements in the City of
Carlsbad", City of Carlsbad, California; April 1993.
"Master Drainage and Storm Water Quality Management Plan", City of Carlsbad,
California; March 1994.
"Tentative Map Drainage Study for La Costa Greens - Phasel Neighborhoods 1.08
through 1.14" Hunsaker & Associates San Diego, Inc. April 17, 2003.
"Hydrology & Hydraulic Study-La Costa Greens Phase T, O'Day Consultants; May
25, 2002
"Hydrology Manual", County of San Diego Department of Public Works - Flood
Control Division; Updated April 1993.
"San Diego County Hydrology Manual", County of San Diego Department of Public
Works - Flood Control Section; June 2003.
"Order No. 2001-01, NPDES No. CAS0108758- Waste Discharge Requirements for
Discharges of Urban Runoff from the Municipal Separate Storm Sewer Systems
(MS4s) Draining the Watersheds ofthe County of San Diego, the Incorporated Cities
of San Diego County, and San Diego Unified Port District, California Regional
Water Quality Control Board - San Diego Region; February 21, 2001.
"Water Quality Pian forthe San Diego Basin", California Regional Water Quality
Control Board - San Diego Region, September 8, 1994.
"Vortechnics Storm Water Treatment System Manual", Vortechnics; Revised May
2000.
DE:de H:\REPORTS\234H18\SWMP01.doc
W.O.2341-18 W11/2004 11:07AM
c5 ---;••- / c s 1 y.
/
mm
2000 4000
SCALE i'=aooo'
^4 HUNSAKER
&. ASSOCIATES
] A H D I I C 01 IMC
rUNNINC
B^CMfBUHC Sv Ollia, Ca 921Z1
SURVRINC ?»tgSt)5SHSC0. EXt&I)5S«-1414
QUADRANGLE MAP WATERSHED
EXHIBIT FOR
LA COSTA GREENS
CARLSBAD, CALIFORNIA
SHEET
1
OF
1 d
3:
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