HomeMy WebLinkAboutCT 13-03; Robertson Ranch West Village Rancho Costera; Storm Water Management Plan for Rancho Costera; 2015-07-08STORM WATER MANAGEMENT PLAN
FOR
RANCHO COSTERA
(ROBERTSON RANCH WEST VILLAGE
PLANNING AREAS 1-11,13, & 23A C,
C.T. 13-03, DRAWING NO. 480-3 & 480-3A)
SWMP No. 13-19
July 8, 2015
Wayne W. Chiang, MS, PE^^I^
QMS
Civil Engineering - Hydroiogy ° Hydraulics ° Sedimentation
P.O. Box 9496
Rancho Santa Fe, CA 92067
(858) 692-0760
ChangtBQ
-TABLE OF CONTENTS -
1.0 Introduction 1
1.1 Vicinity Map 2
1.2 Project Description 2
1.3 Site Map 3
1.4 Constraints and Opportunities 3
2.0 Water Quality Environment 4
2.1 Beneficial Uses 4
2.1.1 Inland Surface Waters 5
2.1.2 Groundwater 5
3.0 Pollutants and Conditions of Concem 6
3.1 Pollutants from Project Area 6
3.2 Pollutants of Concern in Receiving Waters 7
4.0 Permanent Storm Water Best Management Practices 8
4.1 Standard Site Design BMPs 8
4.2 Source Control BMPs 9
4.3 Low Impact Development Site Design BMPs 12
4.4 Treatment Control BMPs 12
4.5 Hydromodification 13
5.0 Storm Water BMP Maintenance 15
6.0 Summary/Conclusions 16
7.0 Certifications 17
Storm Water Standards Questionnaire, E-34
2010 303(d) List
APPENDIX
A. Low Impact Development and Hydromodification Analyses
MAP POCKET
Single Sheet BMP Plan (includes Site Plan and DMAs)
1
1.0 INTRODUCTION
This Storm Water Management Plan (SWMP) addresses water quality requirements
associated with final engineering of the Rancho Costera project (Vesting Tentative Map for
Planning Areas 1-11, 13, and 23A-C of the Robertson Ranch Master Plan) in the city of
Carlsbad. The proposed site development varies by planning area (PA): PA 1 and 23A-C are
designated as open space; PA 2 is a community facility site; PA 3, 5, 6, 9, 10, and 13 are
single-family residential developments; PA 4 is for community recreation, PA 7 and 8 are
multi-family residential; and PA 11 is designated village center/commercial.
The project is subject to hydromodification requirements because it is a priority development
project. This SWMP accompanies the final engineering plans by the project's civil engineer,
O'Day Consultants, and follows the criteria outlined in the City of Carlsbad's January 14,
2011, Standard Urban Storm Water Management Plan (SUSMP). At this stage the
development and engineering plans will only construct the single-family residences. The
community recreation, community facility, multi-family residential, and village
center/commercial planning areas are merely being mass-graded. Future projects will
develop these areas. It is possible that the community recreation will be developed with the
current single-family residential project, but a site plan has not been provided.
According to the City's Storm Water Standards Questionnaire E-34 (attached following this
report text), the current development is subject to priority development project requirements.
The SUSMP outlines the SWMP objectives, which are to identify site opportunities and
constraints, identify pollutants and conditions of concem, follow low impact development
design objectives, describe best management practices (BMPs), and outline maintenance
requirements. BMPs will be utilized to the maximum extent practicable to provide a long-
term solution for addressing runoff water quality. BMPs were selected by O'Day Consultants
and approved during the entitlement process (aka, with the Vesting Tentative Map) to meet
the objectives.
1.1 Vicinity Map
CITY OF OCEANSIDE
SITE
CITY OF VISTA
PACIFIC
OCEAN
CITY OF SAN MARCOS
CITY OF ENCINITAS
1.2 Project Description
This Storm Water Management Plan was prepared to support final engineering for Planning
Areas 1-11, 13 & 23A-C of the Robertson Ranch Master Plan, also known as Rancho
Costera. The project is located south of Calavera Hills Unit 1, CT 76-12, east of Tamarack
Avenue, west of Cannon Road and north of El Camino Real. The proposed site development
varies by planning area (PA): PA 1 and 23A-C are designated as open space; PA 2 is a
community facility site; PA 3, 5, 6, 9, 10, and 13 are single-family residential developments;
PA 4 is for community recreation, PA 7 and 8 are multi-family residential; and PA 11 is
designated village center/commercial.
The current project will construct single-family residences on over 300 detached lots. The
project will mass grade, but not develop, the community, multi-family residential, and village
center/commercial planning areas. Access to the site will be provided via the existing
Glasgow Drive and Edinburgh Drive from the north. Tamarack Avenue from the west, and El
Camino Real from the south. Glasgow Drive and Edinburgh Drive will be extended into the
site, while new streets will establish a connection to Tamarack Avenue (via proposed
Robertson Road) and El Camino Real (via proposed West Ranch Street).
Under pre-project conditions, the Rancho Costera site supports agricultural activities. Storm
runoff from the site generally flows towards the south and occurs as sheet flow over the
natural ground or as surface flow within natural drainage courses. The majority of the runoff
is conveyed to an existing double 8-foot by 4-foot reinforced concrete box culvert (RCB)
under El Camino Real east of Kelly Drive or to an existing 8-foot by 8-foot RCB under El
Camino Real west of Cannon Road. Some of the runoff will also flow onto El Camino Real
where it will be collected by public storm drain systems along with the roadway runoff. The
runoff from all of these areas is ultimately conveyed to Agua Hedionda Creek, which outlets
into Agua Hedionda Lagoon and then the Pacific Ocean.
Under post-project conditions, proposed storm drain systems (drainage ditches, underground
storm drain, and streets) will be constructed to serve Rancho Costera. El Camino Real will
also be improved as part of the overall project, but the improvements are covered under a
separate SWMP by O'Day Consultants. The storm runoff will continue to be conveyed to
Agua Hedionda Creek/Lagoon and the Pacific Ocean. The on-site runoff from the proposed
residential areas will be treated by a series of bioretention basins at various locations
throughout the site. Runoff from the mass-graded pads will be directed to a series of
temporary desiltation basins. Future development within the mass-graded pads will be
responsible for their own SWMPs and associated permanent BMPs. The BMPs in this report
were established during project entitlement and are consistent with the Vesting Tentative
Map.
1.3 Site Map
A Single Sheet BMP Plan containing the Site Map is included in the map pocket.
1.4 Constraints and Opportunities
As shown on the Site Map, the development will occur within a primarily moderate to
steeply sloping area that has historically been used for agriculture. The pre-project drainage
patterns are being maintained by the project.
The current development is a fairly typical hillside subdivision consisting of detached single-
family residences served by public streets, cul-de-sacs, and containing common landscape
areas. The landscaping within the private yards provides opportunities to treat runoff through
contact and bio-filtration by vegetation. Bioretention basins are proposed at twenty-nine
different areas within the development footprint. The bioretention basins will be used to meet
both treatment and hydromodification requirements. O'Day Consultants plans contain more
details on the bioretention basins.
Additional LID/hydromodification BMPs outlined in the City of Carlsbad SUSMP include
pervious pavements, flow-through planters, dry wells, inflitration basins, and cisterns.
Pervious pavements are not being proposed because the streets will be public. The bio-
retention basins are being sized using the flow-through planter criteria to account for
impervious liners (see Section 4.5), so flow-through planters are in effect being proposed.
Dry wells and infiltration basins are not being proposed because the majority of the site
contains hydrologic soil group D, which has a low infiltration rate. Finally, cisterns are
typically not preferred for single-family homes for aesthetic reasons, space considerations,
and low volume of flow capture.
As mentioned in the Introduction, the community recreation, community facility, multi-
family residential, and village center/commercial planning areas currently are merely being
mass-graded. Future projects will develop these areas to the ultimate end use. As a result, the
BMPs for these areas should currently be selected that collect sediment, i.e., desiltation
basins are proposed. In the future when final development occurs within these areas, the
developer and engineer must implement LID and hydromodification BMPs that satisfy the
required criteria for the proposed development.
2.0 WATER QUALITY ENVIRONMENT
2.1 Beneficial Uses
The beneficial uses for the hydrologic unit (see Section 3.1) are included in Tables 1 and 2.
These tables were obtained from the Water Quality Control Plan for the San Diego Basin (9)
compiled on August 28, 2012. The following contains definitions of the beneficial uses in the
tables:
MUN - Municipal and Domestic Supply: Includes uses of water for community,
military, or individual water supply systems including, but not limited to, drinking
water supply.
AGR - Agricultural Supply: 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: Includes uses of water for industrial activities that do not depend
primarily on water quality including, but not limited to, mining, cooling water supply,
hydraulic conveyance, gravel washing, fire protection, or oil well re-pressurization.
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.
BIOL - Biology: Includes uses of water that support designated areas or habitats,
such as established refuges, parks, sanctuaries, ecological reserves, or Areas of
Special Biological Significance (ASBS), where the preservation or enhancement of
natural resources requires special protection.
WARM - Warm Freshwater Habitat: Includes uses of water that support warm
water ecosystems including, but not limited to, preservation or enhancement of
aquatic habitats, vegetation, fish or wildlife, including invertebrates.
WILD - Wildlife Habitat: Includes uses of water that support terrestrial ecosystems
including, but not limited to, preservation and enhancement of terrestrial habitats,
vegetation, wildlife, (e.g., mammals, birds, reptiles, amphibians, invertebrates), or
wildlife water and food sources.
2.1.1 Inland Surface Waters
Inland surface waters for the Agua Hedionda Hydrologic Area (see Section 3.1) have the
beneficial uses shown in Table 1:
Table 1. Beneficial Uses for Inland Surface Waters
Hydrologic
Unit
Code c -o o
2 o o
<L>
tN o <u o /arm "o 2 u
is pwn Unit
Code < OH o Pi pi, s U Pi
904.31 • • • • • • • •
+ Exempted by the Regional Board from the municipal used designation.
• Existing Beneficial Use
2.1.2 Groundwater
Groundwater beneficial uses for the Los Monos Hydrologic Subrea are shown in Table 2:
Table 2. Beneficial Uses for Groundwater
Hydrologic
Unit
Code c o
bb
< s
fc
c/1
fc o
904.31 • • •
Existing Beneficial Use
3.0 POLLUTANTS AND CONDITIONS OF CONCERN
3.1 Pollutants from Project Area
The project is located within the Los Monos Hydrologic Subarea (904.31) of the Agua
Hedionda Hydrologic Area (904.30) of the Carlsbad Hydrologic Unit (904.00), which is
within the San Diego Basin, Region 9. The total drainage area of the hydrologic unit is
approximately 210 square miles. Runoff from the majority of the hydrologic subarea
ultimately drains to Agua Hedionda Lagoon, which is west of the project site. The project
site represents less than one percent of the Carlsbad Hydrologic Unit.
The USGS Quadrangle San Luis Rey Quadrangle Map covers the site and was most recently
published in 2012. The USGS map shows one intermittent (blue line) stream within the site.
The blue line corresponds to the primary unnamed drainage course that flows in a southerly
direction through the middle of the site. The blue line stream confluences with Agua
Hedionda Creek on the southwest side of El Camino Real. Agua Hedionda Creek continues
southwesterly as a blue line stream to Agua Hedionda Lagoon. The Pacific Ocean is the
ultimate discharge location for these blue line features.
Table 3 lists pollutants of concem that are anticipated or can potentially exist at proposed
priority development project sites. The pollutants are from the City of Carlsbad's SUSMP.
This project includes detached residential development; hillside development; and streets,
highways & freeways priority project categories (highlighted yellow in the table). All of the
listed pollutants are either anticipated or can potentially exist at the developed site.
As mentioned in the Introduction, the project will mass grade large pads that will ultimately
be developed with multi-family and commercial uses. However, the ultimate development is
not currently part of this project and will be subject to a future SWMP and BMPs during their
final engineering. Once these future projects are developed they will likely be within the
attached residential, commercial development, restaurants, and park lots categories from
Table 3.
Table 3. Priority Project Pollutants
Priority
Project
Categories
Sediments Nutrients Heavy
Metals
Organic
Compounds
Trash
&
Debris
Oxygen
Demanding
Substances
Oil
&
Grease
Bacteria
&
Viruses
Pesticides
Detached
Residential
Development
X X X X X X X
Attached
Residential
Development
X X X p(i) p(2) P X
Commercial
Development
> one acre
pd) p(i) X p(2) X p(5) X p(3) p(5)
Heavy
Industry X X X X X X
Automotive
Repair Shops X X(")(5) X X
Restaurants X X X X p(l)
Hillside
Development
>5,000 tf
X X X X X X
Parking Lots pd) pd) X X pd) X pd)
Retail
Gasoline
Outlets
X X X X X
Streets,
Highways &
Freeways
X p(l) X X(4) X p(S) X X p(l)
X = Anticipated
P = Potential
(1) A potential pollutant if landscaping exists on-site
(2) A potential pollutant if the project includes uncovered parking areas
(3) A potential pollutant if land use involves food or animal waste products
(4) Including petroleum hydrocarbons
(5) Including solvents
3.2 Pollutants of Concern in Receiving Waters
The receiving waters for the site include Agua Hedionda Creek and Agua Hedionda Lagoon.
According to the January 26, 2010 303(d) list approved by the State Water Resources
Control Board, Agua Hedionda Creek is 303(d) listed for enterococcus, fecal coliform,
manganese, phosphorus, selenium, sulfates, total dissolved solids, total nitrogen as N, and
toxicity. Agua Hedionda Creek is identified with total maximum daily loads (TMDLs) "still
required." Agua Hedionda Lagoon is not 303(d) listed. Based on this information, the project
generates pollutants of concern in the receiving waters for nutrients (nitrogen and
phosphorus), heavy metals (manganese), and bacteria & viruses (enterococcus, fecal
coliform).
For the subject project, a primary source of nutrients is from fertilizers. In addition, heavy
metals are contributed from fuels, adhesives, paints, and other coatings. Bacteria and viruses
are frequently generated from animal fecal wastes.
4.0 PERMANENT STORM WATER BEST MANAGEMENT PRACTICES
To address water quality for the project, best management practices (BMPs) will be
implemented. The following discusses the Standard Site Design, Source Control, and Low
Impact Development design BMPs for the project.
4.1 Standard Site Design BMPs
The City of Carlsbad's standard objectives are required for all projects. The project will
accomplish these goals through the following standard site design BMPs, which are from the
Carlsbad SUSMP dated January 14, 2011:
Standard Stormwater Requirements
Minimize Impervious Surfaces. The project incorporates pervious surfaces, where feasible,
through landscaping within the development area, decomposed granite trails, landscaped
medians, and playing fields/natural surfaces within the recreation areas.
Disconnect Discharges. Roof drains will discharge to adjacent landscape areas, where
feasible. The proposed sidewalks within the single-family residential development are being
designed with a landscaped parkway between the sidewalks and curbs to allow runoff to
drain over adjacent landscape areas. The public street, curb, gutter, and sidewalk runoff will
be directed into proposed bio-retention basins to the maximum extent practicable. The
residential lot's hardscape, driveway, and roof runoff will also be directed into bioretention
basins.
Conserve Natural Areas. The majority of the natural areas beyond the historic agricultural
lands and other previously disturbed areas will be conserved by the project. The existing
major drainage courses within the site will be untouched except at two proposed road
crossings.
Stenciling Inlets and Signage. The drainage inlets within the project will be stenciled with
prohibitive language such as "No Dumping - I live downstream" or approved similar.
Approved signage will be installed at trailheads, along open space areas, and along public
access to the major drainage courses.
Landscape Design. A landscape plan will be prepared that uses drought-tolerant species in
accordance with the City's landscape manual. Native trees and shrubs will be preserved
beyond the majority of the mass-graded pads in order to maximize canopy interception and
promote water conservation. The project will only use water as needed to support the
landscaping. Trees, bushes, grasses, and other plants will be installed in the street medians,
parkways, and common areas in accordance with approved landscape plans.
Water Efficient Irrigation. The irrigation systems will be designed to each landscaped areas
water requirements to avoid over irrigation. Rain shutoff devices will be used to prevent
irrigation after rain events. Drip irrigation shall be utilized, where feasible.
Protect Slopes And Channels. The proposed manufactured slopes will contain drainage
terraces as required by City criteria and will be landscaped with native and drought tolerant
vegetation to the extent feasible. The grading design will prevent runoff from flowing
uncontrolled over the tops of the manufactured slopes. This will be accomplished by
designing building pads and other areas along the top of slopes so that they slope at least 1
percent away from the top of slope. In addition, slope rounding and drainage ditches along
the top of slopes shall be implemented in accordance with City of Carlsbad Standard
Drawing GS-14, where applicable. Riprap energy dissipaters will be used at storm drain
outfalls to reduce outlet velocities to non-erosive rates in accordance with local engineering
standards. The major drainage channels within the site will be preserved. The development is
govemed by a Habitat Management Plan (HMP) that defines open space for preservation of
existing channels, wetlands, and habitat areas.
Trash Receptacles. Each single-family residence will have personal, covered trash
receptacles. Covered trash receptacles shall be installed at appropriate locations within the
proposed recreation areas. Trash receptacles will also ultimately be required in the future
multi-family and commercial/community center areas. These are not required for the current
project, but shall be specified in the future SWMPs required during final engineering of these
areas.
Material Storage Areas. The project does not propose outdoor material storage areas.
Homeowner's shall be required to store any materials having the potential to contaminate
stormwater under cover.
4.2 Source Control BMPs
Source control BMPs will consist of measures to prevent polluted runoff. The following
addresses the source control BMPs from Appendix 1 of the Carlsbad SUSMP:
Table 4. Pollutant Sources and Source Control Checklist
Potential Source
of Runoff Pollutants
Permanent Source
Control BMPs
Operational Source
Control BMPs
On-site storm drain
inlets
Mark all inlets with "No
Dumping -1 live downstream'
Maintain and periodically
repaint inlet markings
Provide stormwater pollution
information to owners, lessees,
and operators (Fact sheet SC-
44 from the CASQA
Stormwater Quality Handbook
at www.cabmphandbooks.com)
Owner/lessee agreements shall
state "Tenant shall not allow
anyone to discharge anything to
storm drains or to store or
deposit materials so as to create
a potential discharge to storm
drains.
Need for future
indoor & structural
pest control
Buildings shall be designed to
avoid openings that would
encourage entry of pests.
Integrated Pest Management (e.g.,
the EPA's Citizen's Guide to Pest
Control and Pesticide Safety)
information shall be provided to
owners, lessees, and operators.
Landscape/Outdoor
Pesticide Use
Final landscape plans will
accomplish all of the
following.
• Preserve existing native trees,
shrubs, and ground cover to
the maximum extent possible.
• Design landscaping to
minimize irrigation and
runoff, to promote surface
inflitration where
appropriate, and to minimize
the use of fertilizers and
pesticides that can contribute
to stormwater pollution.
• Where landscaped areas can
retain or detain stormwater,
specify plants that are
tolerant of saturated soil
conditions.
• Consider using pest-resistant
plants, especially adjacent to
hardscape.
• To ensure successful
establishment, select plants
appropriate to site soils,
slopes, climate, sun, wind,
rain, land use, air movement,
ecological consistency, and
plant interactions
Maintain landscaping using
minimum or no pesticides.
See applicable operational BMPs
in Fact Sheet SC-41, "Building and
Grounds Maintenance," and TC-
30, "Vegetated Swale," in the
CASQA Stormwater Quality
Handbooks at
www.cabmphandbooks.com
Integrated Pest Management (e.g.,
the EPA's Citizen's Guide to Pest
Control and Pesticide Safety)
information shall be provided to
owners, lessees, and operators.
Vehicle and
equipment cleaning
The CC&Rs will define car
washing requirements and
restrictions at the site. The
HOA will be responsible for
enforcing the requirements and
restrictions.
Vehicle/Equipment
Repair and
Maintenance
The CC&Rs will prohibit
repair and maintenance
activities in areas exposed to
precipitation and storm fiows.
The HOA will be responsible
for enforcing this requirement.
Roofing, gutters, and
trim
The architectural design will
avoid roofing, gutters, and trim
made of copper or other
unprotected metals that may
leach into runoff.
Plazas, sidewalks,
and parking lots.
Plazas, sidewalks, and parking lots
shall be swept regularly to prevent
the accumulation of litter and
debris. Debris from pressure
washing shall be collected to
prevent entry into the storm drain
system. Wash water containing
any cleaning agent or degreaser
shall be collected and discharged
to the sanitary sewer and not
discharged to a storm drain.
Pools, spas, ponds,
decorative fountains,
and other water
feachres.
Water features shall be
plumbed to the sanitary sewer
as required by local codes.
See applicable operational BMPs
in Fact Sheet SC-72, "Fountain
and Pool Maintenance," in the
CASQA Stormwater Quality
Handbooks at
www.cabmDhandbooks.com.
Refuse areas • Weekly curb-side refuse
pickup will be provided for
each residential lot.
• The HOA shall provide
maintenance staff that
perform refuse collection and
removal on a weekly basis
(or more, as needed) from the
recreation areas.
Each single-family residence will
be provided with refuse and
recycling containers as specified
by the refuse collection company.
Additional refuse containers shall
be provided in the recreation areas.
These containers shall be
individually covered or under a
covered area.
See Fact Sheet SC-34, "Waste
Handling and Disposal" in the
CASQA Stormwater Quality
Handbooks at
www.cabmphandbooks.com
11
4.3 Low Impact Development Site Design BMPs
Low Impact Development (LID) BMPs must be incorporated into the site design to meet the
City of Carlsbad's January 14, 2011 SUSMP requirements. The integrated LID outlines four
strategies:
1. Optimize the site layout by preserving natural drainage features and designing
buildings and circulation to minimize the amount of roofs and paving.
2. Use pervious surfaces such as turf, gravel, or pervious pavement—or use surfaces that
retain rainfall. All drainage from these surfaces is considered to be "self-retained".
3. Disperse runoff from impervious surfaces on to adjacent pervious surfaces (e.g.,
direct a roof downspout to disperse runoff onto a lawn).
4. Drain impervious surfaces to engineered Integrated Management Practices (IMPs),
such as bioretention facilities. IMPs infiltrate runoff to groundwater and/or percolate
runoff through engineered soil and allow it to drain away slowly.
The project design is in compliance with these strategies. The site layout has been designed
to preserve natural areas beyond the previously disturbed areas in conformance with the
HMP. The perimeter trails will be constructed with pervious decomposed granite. Runoff
from sidewalks will be directed to landscaped parkways between the sidewalks and streets.
Runoff from the roofs will flow towards pervious landscape areas, where possible.
Bioretention basins will be used to treat on-site runoff from the proposed residential areas
and to meet hydromodification requirements (discussed in next section). Bioretention basins
provide high to medium removal effectiveness for the pollutants generated by the project,
which are listed in Table 3. Sizing is included in Appendix A of this report using County of
San Diego's BMP Sizing Spreadsheet, which now supersedes the online BMP Sizing
Calculator. The sizing addresses both LID and hydromodification requirements.
4.4 Treatment Control BMPs
Treatment control BMPs were selected that most efficiently treat the project pollutants of
concem identified in Table 3. Bioretention basins will be used because they have a medium
to high pollutant removal efficiency for the project's pollutants of concem. For treatment
control only, a bioretention basin's surface area must be at least 4 percent of the total area
determined from the Drainage Management Areas. For the project, the bioretention basins
will also provide hydromodification flow control. The sizing is discussed in the next section.
Desiltation basins will be used to capture sediment from the mass-graded pads that will
support future development. The pads will not support activities and the primary pollutants
generated by the pads will be sediment, so desiltation basins are appropriate. Each future
development will be responsible for establishing its own SWMP and BMPs during their final
engineering.
The Carlsbad SUSMP identifies additional treatment control BMPs that were not selected for
the project. The following discusses each of these and the reason they were not selected. Wet
12
ponds and constructed wetlands were not selected because the project does not contain a
perennial water source to support wet ponds or wetlands. These BMPs could also create
vector issues. Infiltration facilities were not selected because the site primarily includes
hydrologic soil group D, which has a very slow infiltration rate. Media filters, higher-rate
bio/media filters (e.g., tree-pit style unit), trash racks, and hydrodynamic devices were not
selected because these types of proprietary devices are not preferred when more accepted
BMPs such as bioretention basins can be implemented. In addition, the pollutant removal
efficiency of some of these devices is low. Vegetated swales were not selected because
bioretention basins are preferred and provide improved removal efficiency. In addition to the
reasons just cited, none of these additional BMPs provides hydromodification benefits, so an
additional storage facility would be required.
Per O'Day Consultants, Lots 1 through 11 adjacent to Glen Avenue, are continuing to treat
storm water on PA 20. The PA 20 treatment area was calculated with C.T. 02-16 that
included portions PA 13 and PA 12. Now all of the Carlsbad Fire Station and more than half
of PA 13 are treating storm water on-site, and the amount of area from PA 13 originally
treated in PA 20 is greatly reduced.
4.5 Hydromodification
The January 14, 2011 SUSMP requires hydromodification (flow control) for priority
development projects to ensure that post-development peak flows do not exceed pre-
development peak flows. Rancho Costera is a priority development project and must meet the
hydromodification requirement. The project does not qualify for any of the exemption
criteria identified in Figure 2-1 HMP Applicability Determination from the Carlsbad
SUSMP. Hydromodification can be accomplished by sizing bioretention facilities using the
criteria in the SUSMP and the County of San Diego's BMP Sizing Spreadsheet.
The proposed project will have twenty-nine bioretention basins spread throughout the site
(see the Single Sheet BMP Plan in Appendix A). The County's BMP Sizing Spreadsheet was
used for the bioretention basin sizing. The County is discontinuing use of the online BMP
Sizing Calculator and replacing it with the spreadsheet. Since the bioretention basins will
contain an impervious liner, they were sized using the fiow-through planter option. This
option accounts for an impervious liner and will yield slightly larger sizing requirements than
the bioretention option.
Data entry for the BMP Sizing Spreadsheet includes the lower fiow threshold, soil group,
slope, and rain gage. A lower flow threshold of O.5Q2 was used because this was determined
by a downstream channel screening assessment {Hydromodification Screening for Rancho
Costera and El Camino Real Widening dated June 19, 2013) by Chang Consultants, which
was approved by the City of Carlsbad. The site is within the Oceanside rainfall basin. O'Day
Consultant's Drainage Study for Rancho Costera (flnal report date not yet established),
which is currently being processed through final engineering indicates that the study area
contains soil group D. The average slope at the existing site is over 15 percent, which is
within the "steep" category. These selections are consistent with the values used in the
entitlement SWMP by O'Day Consultants.
13
The bioretention sizing analyses are included in Appendix A using the flow-through planter
option. The Single Sheet BMP Plan in Appendix A delineates the drainage management
areas tributary to each of the twenty-nine bioretention basins. The drainage basin boundaries
were provided by O'Day Consultants and based on their hydrology study. Each drainage area
tributary to a bioretention basin is subdivided into its streets (asphalt pavement), concrete
(curb, gutter, sidewalks, and driveway ramps contiguous to the sidewalks), and
landscaping/lots. The streets and concrete are impervious. Each residential lot will contain
impervious area from its house, hardscape, and driveway. O'Day Consultants' tentative map
SWMP established the impervious area for each lot's house and hardscape at up to 60
percent of the associated Planning Area's lot size category. O'Day Consultants indicated that
this is a conservative value. The same approach was used for this SWMP, but based on 49 to
60 percent. The impervious home and hardscape area for the 4,000, 5,000, and 8,500 square
foot lot categories are 1,960/2,400, 2,450/3,000, and 5,100 square feet, respectively. In
addition, each driveway was assumed to cover 320 square feet of impervious surface.
The remainder of the tributary area not containing streets, concrete, homes, hardscape, or
driveways will be pervious and primarily support landscaping. The pervious area was
determined by subtracting the sum of the impervious areas from the total drainage area. The
"Drainage Management Areas (DMA) Data" spreadsheet provided Appendix A summarizes
the impervious and pervious areas for each of the twenty-nine drainage areas.
The impervious and pervious areas from the DMA Data spreadsheet were entered into the
County's BMP Sizing Spreadsheet in Appendix A. The BMP Sizing Spreadsheet combines
all impervious areas together since these have the same runoff factor of 1.0. DMA 1 in the
BMP Sizing Spreadsheet represents the total impervious area in each drainage basin while
DMA 2 represents the total pervious area. The results are summarized in Table 5. Table 5
contains the minimum treatment control surface area for each bioretention basin as well as
the necessary storage volumes and oriflce sizing.
The bioretention basins shown on the grading plans should meet the surface area from the
BMP Sizing Spreadsheet. Furthermore, the County of San Diego's Final HMP states that the
ponding layer and storage layer are converted to volumes "so that the project designer can
flexibly configure the ponding layer and storage layer to meet site constraints" (see excerpt in
Appendix A). This has been done on O'Day Consultant's plans, where necessary. If the
available lot area can support the sizing from the Spreadsheet, the basin was graded to
provide the sizing or more. Otherwise, the basin footprint was reduced to fit within the lot.
For instance, the standard County bioretention basin design shows a 4-foot layer below the
surface (1.5 feet of growing medium and 2.5 feet of gravel). This depth can be increased
above 4 feet by increasing the gravel depth to meet the volume requirements in instances
where the available surface area is less than the standard required surface area. The surface
and subsurface storage volumes provided must meet or exceed the minimum calculated
volumes in Table 5. Furthermore, the surface area provided must meet or exceed the
Treatment Control Surface Area in Table 5 to satisfy treatment control sizing. The Treatment
Control Surface Area is calculated on the DMA Data spreadsheet in Appendix A and based
on 4 percent of the total DMA x runoff factor value for each tributary area.
14
Table 5. Summary of Bioretention Basin Sizing
Hyd romodification Requirements Treatment
Control
Surface
Area, sf
Treatment
Lot
Number
Bioretention
Basin
Surface
Area,
sf
Surface
Storage
Volume
Subsurface
Storage
Volume
Orifice
Diameter,
Treatment
Control
Surface
Area, sf
Control
Surface
Area on
Surface
Area,
sf (VI), cf (V2), cf in
Treatment
Control
Surface
Area, sf Plans, sf
345 1 3,517 2,933 2,110 3.4 2,814 3,650
346 2 3,726 3,108 2,236 3.3 2,981 3,870
61 3 8,433 7,033 5,060 4.8 6,746 6,805
246 4 9,835 8,202 5,901 5.0 7,868 8,045
150 5 3,207 2,675 1,924 3.6 2,566 2,745
151 6 2,421 2,019 1,453 2.6 1,937 1,950
152 7 4,085 3,407 2,451 3.4 3,268 3,275
153 8 2,510 2,094 1,506 2.5 2,008 2,745
247 9 1,562 1,303 937 2.1 1,250 3,030
155 10 2,724 2,272 1,634 2.7 2,179 2,940
157 11 5,785 4,825 3,471 4.2 4,628 5,240
344 (W) 12 1,453 1,212 872 1.9 1,162 1,540
344 (E) 13 1,700 1,418 1,020 2.1 1,360 1,445
342 14 1,076 898 646 1.9 861 1,315
340 15 973 811 584 1.6 778 1,315
340 16 2,101 1,753 1,261 2.6 1,681 2,115
339 17 1,826 1,523 1,095 2.3 1,461 2,125
248 18 2,754 2,297 1,653 2.7 2,204 2,945
249 19 3,764 3,139 2,258 3.8 3,011 3,020
250 20 2,591 2,161 1,554 2.6 2,073 2,555
251 21 2,785 2,323 1,671 2.8 2,228 3,760
327 22 4,220 3,520 2,532 3.3 3,376 3,500
347 23 2,207 1,840 1,324 2.3 1,765 1,770
328 24 6,332 5,281 3,799 4.4 5,066 5,180
329 25 6,049 5,045 3,629 4.2 4,839 4,960
346 26 5,391 4,496 3,234 3.8 4,313 7,145
347 (N) 27 4,494 3,748 2,696 3.8 3,595 3,600
347(S) 28 1,630 1,360 978 2.1 1,304 1,400
24 29 3,764 3,139 2,258 3.5 3,011 4,470
Note: The hydromodification portion of the bioretention basins
planter option. The Treatment Control Surface Area is
surface area.
were sized using the flow-through
the minimum bioretention basin
5.0 STORM WATER BMP MAINTENANCE
The developer will be responsible for funding and implementing the operations and
maintenance of the project BMPs. Provisions will be made to transfer operations and
maintenance to the new developer in the event of a change in ownership prior to formation of
15
the homeowner's association. The provisions include providing this final approved SWMP to
the new developer during escrow, so that they are aware of the water quality requirements.
The homeowner's association will ultimately be responsible for ongoing operations and
maintenance within common areas, and individual homeowner's will be responsible for their
private lots as outlined in the CC&Rs. The following describes the specific BMP
maintenance.
Bioretention basins
The drainage outlet from the basins shall be inspected monthly and after large storm events.
Debris, sediment, and other obstructions shall be removed immediately from the outlet. The
habitat shall also be inspected annually and replanted as needed to maintain an adequate
cover.
Landscaping and Vegetated Swales
Maintenance will be performed by landscaping personnel. The vegetation will be maintained
and inspected on a monthly basis by landscape maintenance staff and will be replaced or
replanted, as necessary, to maintain a dense, healthy cover. The vegetation will also be
inspected after major storm events. Maintenance shall include periodic mowing, weed
control, irrigation, reseeding/replanting of bare areas, and clearing of debris. A design grass
height of 6 inches is recommended. Grass clippings shall not be left in grass swales. The
private drainage system will shall be kept clear of debris and inspect prior to and during the
rainy season to ensure it is free-flowing.
Efficient Irrigation
The landscaping personnel shall inspect and maintain the irrigation system on a regular basis.
This will occur during the routine maintenance activities. All valves, heads, shutoff devices,
lines, etc. shall be kept in a properly functioning condition. Any defective parts shall be
replaced immediately. The irrigation system shall be adjusted to prevent excessive runoff
from landscape areas. The irrigation schedule shall be adjusted based on seasonal needs.
Inlet Stenciling
Any stenciling shall be inspected at the beginning and end of each rainy season and repaired
or replaced, as needed.
Hazardous Wastes
Suspected hazardous wastes will be analyzed to determine disposal options. Hazardous
materials are not expected to be generated on-site; however, if discovered, hazardous
materials will be handled and disposed of according to local, state, and federal regulations. A
solid or liquid waste is considered a hazardous waste if it exceeds the criteria listed in the
Califomia Code of Federal Regulations, Title 22, Article 11 (State of Califomia, 1985).
6.0 SUMMARY/CONCLUSIONS
This final SWMP has been prepared in accordance with the City of Carlsbad's January 14,
2011, Standard Urban Storm Water Management Plan, and has evaluated and addressed
potential pollutants associated with the Rancho Costera project and its effects on water
16
quality. This SWMP has been based on the final engineering plans by O'Day Consultants. A
summary of the facts and findings associated with the project and the measures addressed by
this SWMP are as follows:
• The beneficial uses for the receiving waters have been identified. BMPs will be used
to protect the beneficial uses as outlined by the SUSMP.
• The project will not significantly alter drainage pattems and will meet
hydromodification requirements.
• A Storm Water Pollution Prevention Plan for construction activities has been
prepared to address construction-related water quality objectives.
• Permanent BMPs will be incorporated into the project design in the form of site
design, source control, and LID treatment control.
• Details for the treatment control bioretention BMPs are included after this text.
• The proposed BMPs address mitigation measures to protect water quality and
beneficial uses to the maximum extent practicable.
7.0 CERTIFICATIONS
The selection, sizing, and preliminary design of stormwater treatment and other control
measures in this plan meet the requirements of Regional Water Quality Control Board Order
R9-2007-0001 and subsequent amendments.
July 8,2015
Wayne W. Chang^E 46548 Date
1 certify that, as owner/developer of the property described herein, I have read and
understand the requirements of this Storm Water Management Plan (SWMP) and that I am
responsible for ensuring that all storm water treatment measures described within said
SWMP will be properly implemented, monitored, and maintained.
Name: Date
17
C City of
Carlsbad
STORM WATER
STANDARDS
QUESTIONNAIRE
E-34
Development Services
Land Development Engineering
1635 Faraday Avenue
760-602-2750
www.carlsbadca.gov
INSTRUCTIONS :i»
To address post-development pollutants that may be generated from development projects, the City requires that new development and
significant redevelopment priority projects incorporate Permanent Storm Water Best Management Practices (BMP's) into the project
design per the City's Standard Urban Stonnwater Management Plan (SUSMP). To view the SUSMP, refer to the Engineering Standards
(Volume 4, Chapter 2).
Initially this questionnaire must be completed by the applicant In advance of submitting for a development application (subdivision,
discretionary pennits and/or construction permits). The results of the questionnaire detennine the level of stonn water standards that
must be applied to a proposed development or redevelopment project. Depending on the outcome, your project will either be subject to
'Standard Stonnwater Requirements' or be subject to additional criteria called 'Priority Development Project Requirements'. Many
aspects of project site design are dependent upon the storm water standards applied to a project.
Your responses to the questionnaire represent an Initial assessment of the proposed project conditions and Impacts. City staff has
responsibility for making the final assessment after submission of the development application. If staff determines that the questionnaire
was incorrectly filled out and is subject to more stringent storm water standards than Initially assessed by you, this will result In the return
of the development application as Incomplete. In this case, please make the changes to the questionnaire and resubmit to the City.
If you are unsure about the meaning of a question or need help In determining how to respond to one or more of the questions, please
seek assistance from Land Development Engineering staff.
A separate completed and signed questionnaire must be submitted for each new development application submission. Only one
completed and signed questionnaire Is required when multiple development applications forthe same project are submitted concurrently.
In addition to this questionnaire, you must also complete, sign and submit a Project Threat Assessment Form with construction pennits
for the project.
Ptease start by completing Step 1 and follow the instructions. When completed, sign the form at the end and submit this with your
application to the city.
STEPI
i TO BE COMPLETED FOR ALL PROJECTS
To determine If your project Is a priority development project, please answer the following questions:
YES NO
1. Is your project LIMITED TO constructing new or retrofitting paved sidewalks, bicycle lanes or trails that meet
the following criteria: (1) Designed and constructed to direct storm water runoff to adjacent vegetated areas, or
other non-erodible permeable areas; OR (2) designed and constructed to be hydraulically disconnected from
paved streets or roads; OR (3) designed and constructed with penneable pavements or surfaces In
accordance with USEPA Green Streets guidance?
X
2. Is your project LIMITED TO retrofitting or redeveloping existing paved alleys, streets, or roads that are
designed and constructed In accordance with the USEPA Green Streets guidance? X
If you answered "yes" to one or more ofthe above questions, then your project is NOT a priority development project and therefore Is
NOT subject to the storm water criteria required for priority development projects. Go to step 4, mark the last box stating "my
project does not meet PDP requirements" and complete applicant information.
Ifyou answered "no" to both questions, then go to Step 2.
E-34 Page 1 of 3 Effective 6/27/13
<f City of
(j]arlsbad
STORM WATER
STANDARDS
QUESTIONNAIRE
E-34
Development Services
Land Development Engineering
1635 FaradayAvenue
760-602-2750
www.carlsbadca.gov
r'l-' 'ii' *-•'"•••• '.^sTEP^^ _ , «_ ,
To determine if your project is a priority development project, please answer the following questions: YES NO
1. is your project a new development that creates 10,000 square feet or more of Impervious surfaces collectively
over the entire project site? This includes commercial, industrial, residential, mixed-use, and public
development projects on public or private land.
X
2. Is your project creating or replacing 5,000 square feet or more of Impervious surface collectively over the entire
project site on an existing site of 10,000 square feet or more of impervious surface? This includes commercial,
industrial, residential, mixed-use, and public development projects on public or private land.
X
3. Is your project a new or redevelopment project that creates 5,000 square feet or more of Impervious surface
collectively over the entire project site and supports a restaurant? A restaurant is a facility that sells prepared
foods and drinks for consumption, including stationary lunch counters and refreshment stands selling prepared
foods and drinks for immediate consumption.
X
4. Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious surface
collectively over the entire project site and supports a hillside development project? A hillside development
project includes development on any natural slope that is twenty-five percent or greater X
5. Is your project a new or redevelopment project that creates 5,000 square feet or more of Impervious surface
collectively over the entire project site and supports a parking lot. A parking lot is a land area or facility for the
temporary parking or storage of motor vehicles used personally for business or for commerce.
X
6. Is your project a new or redevelopment project that creates 5,000 square feet or more of Impervious surface
collectively over the entire project site and supports a street, road, highway freeway or driveway? A street,
road, highway, freeway or driveway is any paved impervious surface used for the transportation of
automobiles, trucks, motorcycles, and other vehicles.
X
7. Is your project a new or redevelopment project that creates or replaces 2,500 square feet or more of
Impervious surface collectively over the entire site, and discharges directly to an Environmentally Sensitive
Area (ESA)? "Discharging Directly to" includes flow that is conveyed overland a distance of 200 feet or less
from the project to the ESA, or conveyed in a pipe or open channel any distance as an Isolated flow from the
project to the ESA (i.e. not commingles with flows from adjacent lands).*
X
8. Is your project a new development that supports an automotive repair shop? An automotive repair shop is a
facility that is categorized in any one of the following Standard Industrial Classification (SIC) codes: 5013,
5014, 5541, 7532-7534, or 7536-7539.
X
9. Is your project a new development that supports a retail gasoline outlet (RGO)? This category Includes RGO's
that meet the following criteria: (a) 5,000 square feet or more or (b) a project Average Daily Traffic (ADT) of
100 or more vehicles per day.
X
10. Is your project a new or redevelopment project that results In the disturbance of one or more acres of land and
are expected to generate pollutants post construction? X
11.1s your project located within 200 feet of the Pacific Ocean and (1) creates 2,500 square feet or more of
impervious surface or (2) Increases Impervious surface on the property by more than 10%? X
If you answered "yes" to one or more of the above questions, you ARE a priority development project and are therefore subject to
Implementing structural Best Management Practices (BMP's) In addition to Implementing Standard Storm Water Requirements such
as source control and low Impact development BMP's. A Storm Water Management Plan (SWMP) must be submitted with your
application(s) for development. Go to step 3 for redevelopment projects. For new projects, go to step 4 at the end of this
questionnaire, check the "my project meets PDP requirements" box and complete applicant information.
If you answered "no" to all of the above questions, you ARE NOT a priority development project and are therefore subject to
Implementing only Standard Storm Water Requirements such as source controi and low impact development BMP's required for all
development projects. A Storm Water Management Plan (SWMP) is not required with your applicatlon(s) for development. Go to step
4 at the end of this questionnaire, check the "my project does not meet PDP requirements" box and complete applicant
information.
E-34 Page 2 of 3 Effective 6/27/13
C City of
(parlsbad
STORM WATER
STANDARDS
QUESTIONNAIRE
E-34
Development Services
Land Development Engineering
1635 Faraday Avenue
760-602-2750
www.carlsbadca.gov
. STEP 3 .Vv • , ••.•••/•'..u'l':. ••)-.
TO BE COMPLETED FOR REDEVELOPMENT PROJECTS THAT ARE PRIORITY DEVELOPEMENT PROJECTS ONLY .
Complete the questions below regarding your redevelopment project: YES NO Does the redevelopment project result in the creation or replacement of impervious surface in an amount of less than
50% ofthe surface area of the previously existing development?
Ifyou answered "yes," the structural BMP's required for Priority Development Projects apply only to the creation or replacement of
Impervious surface and not the entire development. Go to step 4, check the "my project meets PDP requirements" box and
complete applicant information.
Ifyou answered "no," the structural BMP's required for Priority Development Projects apply to the entire development. Go to step 4,
check the "my project meets PDP requirements" box and complete applicant information.
CHECK THE APPROPRIATE BOX AND COMPLETE APPLICANT INFORMATION
•
My project meets PRIORITY DEVELOPMENT PROJECT (PDP) requirements and must comply with additional stonnwater
criteria per the SUSMP and I understand I must prepare a Storm Water Management Plan for submittal at time of application.
I understand flow control (hydromodification) requirements may apply to my project. Refer to SUSMP for details.
My project does not meet PDP requirements and must only comply with STANDARD STORMWATER REQUIREMENTS per
the SUSMP. As part of these requirements, I will Incorporate low impact development strategies throughout my project.
Applicant Information and Signature Box
North of El Camino Real between
Tamarack Av and Cannon Rd. Address: Accessor's Parcel Number(s): 208-010-41
Applicant Name: Peter Kim
Applicant Title:
Director of Land Development
Date: 7/ -^//^
This Box for City Use Only
City Concurrence: YES NO City Concurrence:
By:
Date:
Project ID:
* 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 forthe
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 Dlego Basin (1994) and amendments); areas designated as preserves or their
quivalent under the Multi Species Conservation Program within the Cities and County of San Dlego; and any other equivalent
environmentally sensitive areas which have been identified by the Copermittees.
E-34 Page 3 of 3 Effective 6/27/13
CATEGORY 5 Regional Board 9 - San Diego Region
January 26, 2010
2008 CALIFORNIA 303(d) LIST OF WATER QUALITY LIMITED SEGMENTS
Draft 2008 California 305(b)/303(d) Integrated
Report
Category 5 criteria: 1) A water segment where standards are not met and a TMDL is required, but not yet completed, for at least one of the pollutnats being
listed for this segment.
* USGS HUC = US Geological Survey Hydrologic Unit Code. Calwater = State Water Resources Control Board hydrological subunit area or even smaller planning watershed.
** TMDL requirement status definitions for listed pollutants are: A= TMDL still required, B= being addressed by USEPA approved TMDL, C= being addressed by
action other than a TMDL
*** Dates relate to the TMDL requirement status, so a date for A= TMDL scheduled completion date, B= Date USEPA approved TMDL, and C= Completion date for
action other than a TMDL
REGION WATER
BODY NAME
WATER
TYPE
WATERSHED*
CALWATER/
USGS HUC
POLLUTANT
POTENTIAL SOURCES
Relevant Notes
ESTIMATED FIRST TMDL
AREA YEAR REQUIREMENT DATE***
ASSESSED LISTED STATUS**
Agua
Hedionda
Creek
River & 90431000 /
Stream 18070303
Enterococcus
° Natural Sources
° Unknown Nonpoint Source
° Urban Runoff/Storm Sewers
7 Miles 2008 5A 2019
Fecal Coliform
° Natural Sources
° Unknown Nonpoint Source
° Urban Runoff/Storm Sewers
7 Miles 2008 5A 2019
Manganese
° Source Unknown
7 Miles 2006 5A 2019
Phosphorus
° Natural Sources
° Unknown Nonpoint Source
7 Miles 2008 5A 2019
6/7/2014
REGION WATER
BODY NAME
WATER
TYPE
WATERSHED*
CALWATER/
USGS HUC
POLLUTANT
POTENTIAL SOURCES
Relevant Notes
ESTIMATED FIRST TMDL
AREA YEAR REQUIREMENT DATE***
ASSESSED LISTED STATUS**
Urban Runoff/Storm Sewers
Selenium
° Source Unknown
7 Miles 2006 5A 2019
Sulfates
° Other Urban Runoff
° Point Source
° Unknown Nonpoint Source
° Unknown Point Source
7 Miles 2006 5A 2019
Total Dissolved Solids
° Unknown Nonpoint Source
° Unknown Point Source
° Urban Runoff/Storm Sewers
7 Miles 2002 5A 2019
Total Nitrogen as N
° Natural Sources
° Unknown Nonpoint Source
° Urban Runoff/Storm Sewers
7 Miles 2008 5A 2019
Toxicity
° Natural Sources
° Unknown Nonpoint Source
° Urban Runoff/Storm Sewers
7 Miles 2008 5A 2019
6/7/2014
APPENDIX A
LOW IMPACT DEVELOPMENT
AND HYDROMODIFICATION ANALYSES
SUMMARY
The SUSMP requires that Drainage Management Areas (DMA) be delineated for various surface
types. The drainage basin boundaries were provided by O'Day Consultants and based on their
hydrology study. Each drainage area tributary to a bioretention basin is subdivided into its
DMA's, which include streets (asphalt pavement), concrete (curb, gutter, sidewalks, and
driveway ramps contiguous to the sidewalks), and landscaping/lots. The DMAs are illustrated on
the exhibit in the map pocket. The streets and concrete are impervious. Each residential lot will
contain impervious area from its house, hardscape, and driveway. O'Day Consultants' tentative
map SWMP established the impervious area for each lot's house and hardscape at 60 percent of
the associated Planning Area's lot size category. O'Day Consultants indicated that this is a
conservative value. The same approach was used for this SWMP. The impervious home and
hardscape area for the 4,000, 5,000, and 8,500 square foot lot categories are 2,400, 3,000, and
5,100 square feet, respectively. In addition, each driveway was assumed to cover 320 square feet
of impervious surface.
The impervious and pervious areas associated with the DMAs are included on the attached DMA
Data spreadsheet. The impervious and pervious areas from the DMA Data spreadsheet were then
entered into the attached County BMP Sizing Spreadsheet. The BMP Sizing Spreadsheet
combines all impervious areas together since these have the same runoff factor of 1.0. DMA 1 in
the BMP Sizing Spreadsheet represents the total impervious area in each drainage basin while
DMA 2 represents the total pervious area. The BMP Sizing Spreadsheet provides the necessary
bioretention basin sizing, which is based on the flow-through planter factors since the basins will
contain an impervious liner.
Section 7 Hydromodiflcation Management Plan
Table 7-4. Sizing Factors for Flow-Through Planters
Lower Flow
Threshold Soil Group Slope Rain Gauge A Vi V2
0.5Q2 C Moderate Oceanside 0.075 0.0625 0.0450
0.5Q2 C Steep Oceanside 0.065 0.0542 0.0390
0.5Q2 D Flat Oceanside 0.070 0.0583 0.0420
0.5Q2 D Moderate Oceanside 0.070 0.0583 0.0420
0.5Q2 D Steep Oceanside 0.050 0.0417 0.0300
0.5Q2 A Flat L Wohlford N/A N/A N/A
0.5Q2 A Moderate L Wohlford N/A N/A N/A
0.5Q2 A Steep L Wohlford N/A N/A N/A
0.5Q2 B Flat L Wohlford N/A N/A N/A
0.5Q2 B Moderate L Wohlford N/A N/A N/A
0.5Q2 B Steep L Wohlford N/A N/A N/A
0.5Q2 C Flat L Wohlford 0.070 0.0583 0.0420
0.5Q2 C Moderate LWotilford 0.070 0.0583 0.0420
0.5Q2 C Steep L Wohlford 0.050 0.0417 0.0300
0.5Q2 D Flat LWotilford 0.055 0.0458 0.0330
0.5Q2 D Moderate L Wohlford 0.055 0.0458 0.0330
0.5Q2 D Steep L Wohlford 0.045 0.0375 0.0270
0.3Q2 A Flat Lindbergh N/A N/A N/A
0.3Q2 A Moderate Lindbergh N/A N/A N/A
0.3Q2 A Steep Lindbergh N/A N/A N/A
0.3Q2 B Flat Lindbergh N/A N/A N/A
0.3Q2 B Moderate Lindbergh N/A N/A N/A
0.3Q2 B Steep Undbergh N/A N/A N/A
0.3Q2 C Flat Undbergh 0.130 0.1083 0.0780
0.3Q2 C Moderate Undbergh 0.130 0.1083 0.0780
0.3Q2 C Steep Lindbergh 0.100 0.0833 0.0600
0.3Q2 D Flat Lindbergh 0.105 0.0875 0.0630
0.3Q2 D Moderate Lindbergh 0.105 0.0875 0.0630
0.3Q2 D Steep Lindbergh 0.075 0.0625 0.0450
0.3Q2 A Flat Oceanside N/A N/A N/A
0.3Q2 A Moderate Oceanside N/A N/A N/A
0.3Q2 A Steep Oceanside N/A N/A N/A
0.3Q2 B Flat Oceanside N/A N/A N/A
0.3Q2 B Moderate Oceanside N/A N/A N/A
0.3Q2 B Steep Oceanside N/A N/A N/A
0.3Q2 C Flat Oceanside 0.105 0.0875 0.0630
0.3Q2 C Moderate Oceanside 0.105 0.0875 0.0630
0.3Q2 C Steep Oceanside 0.085 0.0708 0.0510
0.3Q2 D Flat Oceanside 0.090 0.0750 0.0540
Brown Caldwell
7-12
Use of contents on this slieet is subject to the limitations specified at the end of this document
S:\Projects\San Diego County\133904 - SDCo Hydromod Management Plan\WP\HMP\08_Final HMP Jan20f 1\I04720 FINAL San Diego HMP. Jan2011 docx
RANCHO COSTERA DRAINAGE MANAGEMENT AREAS (DMA) DATA
BMPI
129,098 Total Area
7 Number of Lots
5100 Footprint of Each House
320 Driveway Area per Lot
37,940 Total Impervious Area in All Lots
Surface
Impervious
Pervious
BMP 2
Homes, Driveways, Hardscape Streets
37,940 18,572
0 0
Curb, Gutter, Sidewalk
7,302
0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 63,814 1.0 63,814
65,284 65,284 0.1 6,528
129,098 70,342 Total
2,814 4% of Total
123,780 Total Area
8 Number of Lots
5100 Footprint of Each House
320 Driveway Area per Lot
43,360 Total impervious Area in All Lots
Surface
Impervious
Pervious
BMP 3
Homes, Driveways, Hardscape Streets
43,360 17,954
0 0
Curb, Gutter, Sidewalk
7,743
0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 69,057 1.0 69,057
54,723 54,723 0.1 5,472
123,780 74,529 Total
2,981 4% of Total
252,290 Total Area
21 Number of Lots
5100 Footprint of Each House
320 Driveway Area per Lot
113,820 Total Impervious Area in All Lots
Surface
Impervious
Pervious
Homes, Driveways, Hardscape Streets
113,820 28,933
0 0
Curb, Gutter, Sidewalk
15,506
0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 158,259 1.0 158,259
104,031 104,031 0.1 10,403
262,290 168,662 Total
6,746 4% ofTotal
BMP 4
288,492 Total Area
38 Number of Lots
3000 Footprint of Each House
320 Driveway Area per Lot
126,160 Total Impervious Area in All Lots
Surface
Impervious
Pervious
BMPS
Homes, Driveways, Hardscape Streets
126,160 38,429
0 0
Curb, Gutter, Sidewalk
21,909
0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 186,498 1.0 185,498
101,994 101,994 0.1 10,199
288,492 196,697 Total
7,868 4% of Total
147,538 Total Area
11 Number of Lots
2400 Footprint of Each House
320 Driveway Area per Lot
29,920 Total Impervious Area in All Lots
Surface
Impervious
Pervious
BMPS
Homes, Driveways, Hardscape Streets
29,920 17,239
0 0
Curb, Gutter, Sidewalk
7,715
0
Landscaping Total Runoff Factor DM A Area x Runoff Factor
0 54,874 1.0 54,874
92,664 92,664 0.1 9,266
147,538 64,140 Total
2,566 4% ofTotal
75,355 Total Area
9 Number of Lots
1960 Footprint of Each House
320 Driveway Area per Lot
20,520 Total Impervious Area in All Lots
Surface
Impervious
Pervious
Homes, Driveways, Hardscape
20,520
Streets Curb, Gutter, Sidewalk
16,630 8,282
0 0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 45,432 1.0 45,432
29,923 29,923 0.1 2,992
75,355 48,424 Total
1,937 4% OfTotal
BMP 7
132,851 Total Area
17 Number of Lots
1960 Footprintof Each House
320 Driveway Area per Lot
38,760 Total Impervious Area in All Lots
Surface
Impervious
Pervious
BMPS
Homes, Driveways, Hardscape Streets
38,760 25,271
0 0
Curb, Gutter, Sidewalk
11,975
0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 76,007 1.0 76,007
56,844 56,844 0.1 5,684
132,851 81,691 Total
3,268 4% of Total
74,870 Total Area
9 Number of Lots
2400 Footprint of Each House
320 Driveway Area per Lot
24,480 Total Impervious Area in All Lots
Surface
Impervious
Pervious
BMP 9
Homes, Driveways, Hardscape Streets
24,480 15,011
0 0
Curb, Gutter, Sidewalk
7,974
0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 47,465 1.0 47,465
27,405 27,405 0.1 2,741
74,870 50,206 Total
2,008 4% of Total
48,944 Total Area
6 Number of Lots
3000 Footprint of Each House
320 Driveway Area per Lot
19,920 Total Impervious Area in All Lots
Surface
Impervious
Pervious
Homes, Driveways, Hardscape Streets
19,920 5,727
0 0
Curb, Gutter, Sidewalk
3,628
0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 29,275 1.0 29,275
19,669 19,669 0.1 1,967
48,944 31,242 Total
1,250 4% of Total
BMP 10
81,379
9
2400
320
24,480
Total Area
Number of Lots
Footprint of Each House
Driveway Area per Lot
Total Impervious Area in All Lots
Surface
Impervious
Pervious
BMP 11
201,968
25
1960
320
56,360
Homes, Driveways, Hardscape
24,480
0
Total Area
Streets Curb, Gutter, Sidewalk Landscaping
17,740 9,265 0
0 0 29,894
Total Runoff Factor DMA Area x Runoff Factor
51,485 1.0 51,485
29,894 0.1 2,989
81,379 54,474 Total
2,179 4% of Total
Number of Lots (Assume each of the two Rec Areas contains impervious area equivalent to single-family lot)
Footprint of Each House
Driveway Area per Lot (based on 23 residential lots only)
Total Impervious Area in All Lots
Surface Homes, Driveways, Hardscape
Impervious 56,360
Pervious 0
BMP 12
41,215 Totai Area
3 Number of Lots
2400 Footprint of Each House
320 Driveway Area per Lot
8,160 Total Impervious Area in All Lots
Streets Curb, Gutter, Sidewalk Landscaping
34,600 16,800 0
0 0 94,208
Total
107,760
94,208
201,968
Runoff Factor DMA Area x Runoff Factor
1.0
0.1
107,760
9,421
117,181
4,687
Total
4% of Total
Surface
Impervious
Pervious
Homes, Driveways, Hardscape Streets
8,160 15,787
0 0
Curb, Gutter, Sidewalk
3,757
0
Landscaping Total Runoff Factor DM A Area x Runoff Factor
0 27,704 1.0 27,704
13,512 13,512 0.1 1,351
41,216 29,055 Total
1,162 4% ofTotal
BMP 13
51,043
3
2400
320
8,160
Total Area
Numberof Lots
Footprint of Each House
Driveway Area per Lot
Total Impervious Area in All Lots
Surface
Impervious
Pervious
BMP 14
40,693
0
0
0
0
Homes, Driveways, Hardscape
8,160
Total Area
Numberof Lots
Footprint of Each House
Driveway Area per Lot
Total Impervious Area in All Lots
Streets Curb, Gutter, Sidewalk
14,299 9,645
0 0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 32,104 1.0 32,104
18,939 18,939 0.1 1,894
51,043 33,998 Total
1,360 4% ofTotal
Surface Homes, Driveways, Hardscape
Impervious 0
Pervious 0
BMP 15
30,574 Total Area
0 Number of Lots
0 Footprint of Each House
0 Driveway Area per Lot
0 Total Impervious Area in All Lots
Streets Curb, Gutter, Sidewalk
14,458 4,942
0 0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 19,400 1.0 19,400
21,293 21,293 0.1 2,129
40,693 21,529 Total
861 4% of Total
Surface
Impervious
Pervious
Homes, Driveways, Hardscape Streets
0 13,518
0 0
Curb, Gutter, Sidewalk
4,697
0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 18,215 1.0 18,215
12,359 12,359 0.1 1,236
30,574 19,451 Total
778 4% of Total
BMP 16
78,168
0
0
0
0
Total Area
Number of Lots
Footprint of Each House
Driveway Area per Lot
Total Impervious Area in All Lots
Surface
Impervious
Pervious
BMP 17
60,010
0
0
0
0
Homes, Driveways, Hardscape
0
0
Total Area
Number of Lots
Footprint of Each House
Driveway Area per Lot
Total Impervious Area in All Lots
Streets
30,931
0
Curb, Gutter, Sidewalk
7,080
0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 38,011 1.0 38,011
40,157 40,157 0.1 4,016
78,168 42,027 Total
1,681 4% of Total
Surface Homes, Driveways, Hardscape
Impervious 0
Pervious 0
BMP 18
83,561 Total Area
10 Number of Lots
3000 Footprint of Each House
320 Driveway Area per Lot
33,200 Total Impervious Area in All Lots
Streets
28,176
0
Curb, Gutter, Sidewalk
5,728
0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 33,904 1.0 33,904
26,106 26,106 0.1 2,611
60,010 36,515 Total
1,461 4% of Total
Surface
Impervious
Pervious
Homes, Driveways, Hardscape Streets
33,200 12,321
0 0
Curb, Gutter, Sidewalk
6,403
0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 51,924 1.0 51,924
31,637 31,637 0.1 3,164
83,561 55,088 Total
2,204 4% of Total
BMP 19
168,913
15
2450
320
41,550
Total Area
Number of Lots
Footprint of Each House
Driveway Area per Lot
Total Impervious Area in All Lots
Surface Homes, Driveways, Hardscape
Impervious 41,550
Pervious 0
BMP 20
79,929 Total Area
10 Number of Lots
3000 Footprint of Each House
320 Driveway Area per Lot
33,200 Total Impervious Area in All Lots
Streets Curb, Gutter, Sidewalk
13,408 9,912
0 0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 64,870 1.0 64,870
104,043 104,043 0.1 10,404
168,913 75,274 Total
3,011 4% OfTotal
Surface
Impervious
Pervious
BMP 21
87,064
Homes, Driveways, Hardscape
33,200
0
Total Area
Streets
9,585
0
Curb, Gutter, Sidewalk
5,908
0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 48,693 1.0 48,693
31,236 31,236 0.1 3,124
79,929 51,817 Total
2,073 4% of Total
11 Number of Lots
3000 Footprint of Each House
320 Driveway Area per Lot
36,520 Total Impervious Area in All Lots
Surface
Impervious
Pervious
Homes, Driveways, Hardscape
36,520
Streets Curb, Gutter, Sidewalk
9,737 5,964
0 0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 52,221 1.0 52,221
34,843 34,843 0.1 3,484
87,064 55,705 Total
2,228 4% of Total
BMP 22
127,142
13
3600
320
50,960
Total Area
Number of Lots
Footprint of Each House
Driveway Area per Lot
Total Impervious Area in All Lots
Surface
Impervious
Pervious
BMP 23
61,497
Homes, Driveways, Hardscape
50,960
0
Total Area
Streets Curb, Gutter, Sidewalk
20,975 7,719
0 0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 79,654 1.0 79,654
47,488 47,488 0.1 4,749
127,142 84,403 Total
3,376 4% OfTotal
5 Number of Lots
3600 Footprint of Each House
320 Driveway Area per Lot
19,600 Total Impervious Area in All Lots
Surface
Impervious
Pervious
BMP 24
218,973
19
2940
320
61,940
Homes, Driveways, Hardscape
19,600
0
Total Area
Number of Lots
Footprint of Each House
Driveway Area per Lot
Total Impervious Area in All Lots
Streets Curb, Gutter, Sidewalk
15,558 7,044
0 0
Landscaping Total Runoff Factor DM A Area x Runoff Factor
0 42,202 1.0 42,202
19,295 19,295 0.1 1,930
61,497 44,132 Total
1,765 4% ofTotal
Surface
Impervious
Pervious
Homes, Driveways, Hardscape
61,940
Streets Curb, Gutter, Sidewalk
38,434 16,004
0 0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 116,378 1.0 116,378
102,595 102,595 0.1 10,260
218,973 126,638 Total
5,066 4% OfTotal
BMP 25
203,952
19
2940
320
61,940
Total Area
Number of Lots
Footprint of Each House
Driveway Area per Lot
Total Impervious Area in All Lots
Surface
Impervious
Pervious
BMP 26
169,190
3600
320
31,360
Homes, Driveways, Hardscape
61,940
0
Total Area
Number of Lots
Footprint of Each House
Driveway Area per Lot
Total Impervious Area in All Lots
Streets Curb, Gutter, Sidewalk Landscaping
34,439 15,378 0
0 0 92,195
Total
111,757
92,195
203,952
Runoff Factor DMA Area x Runoff Factor
1.0
0.1
111,757
9,220
120,977
4,839
Total
4% of Total
Surface
Impervious
Pervious
BMP 27
163,564
11
3600
320
43,120
Homes, Driveways, Hardscape
31,360
0
Total Area
Number of Lots
Footprint of Each House
Driveway Area per Lot
Total Impervious Area in All Lots
Streets
50,414
0
Curb, Gutter, Sidewalk
19,222
0
Landscaping
0
68,194
Total
100,996
68,194
169,190
Runoff Factor DMA Area x Runoff Factor
1.0
0.1
100,996
6,819
107,815
4,313
Total
4% ofTotal
Surface
Impervious
Pervious
Homes, Driveways, Hardscape Streets
43,120 27,150
0 0
Curb, Gutter, Sidewalk
11,419
0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 81,689 1.0 81,689
81,875 81,875 0.1 8,188
163,564 89,877 Total
3,595 4% of Total
BMP 28
49,588
0
0
0
0
Total Area
Number of Lots
Footprint of Each House
Driveway Area per Lot
Total Impervious Area in All Lots
Surface Homes, Driveways, Hardscape
Impervious 0
Pervious 0
BMP 29
137,671 Total Area
12 Number of Lots
3000 Footprint of Each House
320 Driveway Area per Lot
39,840 Total Impervious Area in All Lots
Streets Curb, Gutter, Sidewalk
22,416 8,299
0 0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 30,715 1.0 30,715
18,873 18,873 0.1 1,887
49,588 32,602 Total
1,304 4% of Total
Surface
Impervious
Pervious
Homes, Driveways, Hardscape Streets
39,840 20,857
0 0
Curb, Gutter, Sidewalk
7,648
0
Landscaping Total Runoff Factor DMA Area x Runoff Factor
0 68,345 1.0 68,345
69,326 69,326 0.1 6,933
137,671 75,278 Total
3,011 4% of Total
Project Info
Project Name: Rancho Costera
Project Applicant: Toll Brothers
Jurisdiction: City of Carlsbad
Parcel (APN): 208-010-41
Hydrologic Unit: Carlsbacl
Rain Gauge: Oceanside
Total Project Area: 78.5
Channel Susceptibility: Low
Page 1 of 61
BMP#1
BMPType: Flow-Through Planter
Low Flow Threshold: 0.5Q2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soil Type Slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 63814 D Steep 1.0 0.05 0.0417 0.03 3191 2661 1914
DMA2 65284 D Steep 0.1 0.05 0.0417 0.03 326 272 196
DMA3 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 3517.12 2933 2110
Note: HMP Sizing Factors per Section 7 of HMP
Page 2 cf 61
Orifice #1
(1) Q=Cd X A X (2gH)0.5 Orifice Discharge Equation
(2) A= [%Q2 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Area Equation (%Q2 is low flow threshold)
g=32.2
ft/s2
H= 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
10" Ponding
18" Amended Soil 1
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor DMA Area (ac) Orifice Flow - %Q2 Orifice Area (in2)
Soil Type Cover Slope (cfs/ac) (cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 1.465 0.179 4.36
DMA2 Oceanside D Scrub Steep 0.244 1.499 0.183 4.46
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.362 8.83 3.35
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.3
(Must be less than 96 Hrs)
Page 3 of 61
BMP #2
BMP Type: Flow-Through Planter
Low Fiow Threshoid: 0.5Q2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP size
Area (sf) Soii Type Siope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 69057 D Steep 1.0 0.05 0.0417 0.03 3453 2880 2072
DMA2 54723 D Steep 0.1 0.05 0.0417 0.03 274 228 164
DMA3 0 0 C 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 3726.465 3108 2236
Note: HMP Sizing Factors per Section 7 of HMP
Page 4 of 61
Orifice #2
(1) Q=Cd X A X (2gH)0.5 Orifice Discharge Equation
(2) A=[%Q2xADMAl/Cdx(2gH)0.5
Cd= 0.6
dimensionless
Orifice Area Equation (%Q2 is low flow threshold)
^
10" Ponding
g=32.2
ft/s2
H= 1.5
ft
t 18" Amended Soil 1
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2'(Typical for Vault)
30" Storage
T
18"
A.
Flow Control Orifice
Bioretention / Flow-Through Planter
A = Cross Sectiona Area of Orifice
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 1.585 0.193 4.72
DMA2 Oceanside D Scrub Steep 0.244 1.256 0.153 3.74
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA7 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.347 8.47 3.28
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.5
(Must be less than 96 Hrs)
Page 5 of 61
BMP #3
BMP Type: Flow-Through Planter
Low Flow Threshold: 0.5Q2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP >ize
Area (sf) Soil Type Slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 1582S9 D Steep 1.0 0.05 0.0417 0.03 7913 6599 4748
DMA2 104031 D Steep 0.1 O.OS 0.0417 0.03 520 434 312
DMA3 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA? 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Totai 8433.105 7033 5060
Note: HMP Sizing Factors per Section 7 of HMP
Page 6 of 61
Orifice #3
(1) Q=Cd X A X (2gH)0.5 Orifice Discharge Equation
(2) A= [%Q2 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Area Equation (%Q2 is low flow threshold)
g=32.2
ft/s2
H= 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
^
10" Ponding
18" Amended Soil i ^
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2)
DMAl Oceanside D Scrub Steep 0.244 3.633 0.443 10.82
DMA2 Oceanside D Scrub Steep 0.244 2.3S8 0.291 7.11
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA7 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
Drawdown (Hrs)
0.735 17.94 4.78
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
2.7
(Must be less than 96 Hrs)
Page 7 of 61
BMP #4
BMP Type: Flow-Through Planter
Low Fiow Threshold: 0.5Q2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soil Type stope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 1S6498 D Steep 1.0 0.05 0.0417 0.03 9325 7777 S595
DMA2 101994 D Steep 0.1 0.05 0.0417 0.03 510 425 306
DMA3 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Totai 9S34.S7 8202 5901
Note: HMP Sizing Factors per Section 7 ot HMP
Page a of 61
Orifice #4
(1) Q=Cd X A X (2gH)0.5 Orifice Discharge Equation
(2) A= [%Q2 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Area Equation (%Q2 is low flow threshold)
¥
10" Ponding
g=32.2
ft/s2
H= 1.5
ft
18" Amended Soil
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 4.281 0.522 12.75
DMA2 Oceanside D Scrub Steep 0.244 2.341 0.286 6.98
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA7 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.808 19.73 5.01
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.8
(Must be less than 96 Hrs)
Page 9 of 61
BMP #5
BMF Type: Flow-Through Planter
Low Fiow Threshoid: 0.5Q2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (st) Soli Type siope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 54874 D steep 1.0 0.05 0.0417 0.03 2744 2288 1646
DMA2 92664 D Steep 0.1 0.05 0.0417 0.03 463 386 278
DMA3 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 3207.02 2675 1924
Note: HMP Sizing Factors per Section 7 of HMP
Page 10 of 61
Orifice #5
(1) Q=Cd X A X (2gH)0.5 Orifice Discharge Equation
(2) A=[%Q2xADMA]/Cdx(2gH)0.5
Cd= 0.6
dimensionless
Orifice Area Equation (%Q2 is low flow threshold)
g=32.2
ft/s2
H= 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
^
10" Ponding
18" Amended Soil
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 1.260 0.154 3.75
DMA2 Oceanside D Scrub Steep 0.244 2.127 0.260 6.34
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA7 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
Drawdown (Hrs)
0.413 10.09 3.58
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
l.S
(Must be less than 96 Hrs)
Page 11 of 61
BMP #6
BMP Type: Flow-Through Planter
Low Fiow Threshold: 0.5Q2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soil Type Slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 45432 D Steep 1.0 0.05 0.0417 0.03 2272 1895 1363
DMA2 29923 D Steep 0.1 O.OS 0.0417 0.03 150 125 90
DMA3 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Totai 2421.215 2019 1453
Note: HMP Sizing Factors per Section 7 of HMP
Page 12 of 61
Orifice #6
(1) Q=CdxAx(2gH)0.5
(2) A= [%Q2 x ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 is low flow threshold)
^
10" Ponding t
g=32.2
ft/s2
H = 1.5
ft
18" Amended Soil ."^V-oToi^"*!:.
I |, %-.i^ :'«'='L''i.
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 1.043 0.127 3.11
DMA2 Oceanside D Scrub Steep 0.244 0.68? 0.084 2.05
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.211
Tot. Orifice Flow
(cfs)
5.15
Tot. Orifice Area
(in2)
2.56
Orifice Dia
(in)
Drawdown (Hrs) 2.7
(Must be less than 96 Hrs)
Page 13 of 61
BMP #7
BMP Type: Flow-Through Planter
Low Flow Threshold: 0.SQ2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soil Type Siope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 76007 D Steep 1.0 0.05 0.0417 0.03 3800 3169 2280
DMA2 56844 D steep 0.1 O.OS 0.0417 0.03 284 237 171
DMA3 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 4084.57 3407 2451
Note: HMP Sizing Factors per Section 7 of HMP
Page 14 of 61
Orifice #7
(1) Q=Cd X A X (2gH)0.5
(2) A= [%02 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 is low flow threshold)
g=32.2
ft/s2
H = 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
10" Ponding
18" Amended Soil
18"
30" Storage
L
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor DMA Area (ac) Orifice Flow - %Q2 Orifice Area (In2)
Soil Type Cover Slope (cfs/ac) (cfs)
DMAl Oceanside D Scrub Steep 0.244 1.745 0.213 5.20
DMA2 Oceanside D Scrub Steep 0.244 1.305 0.159 3.89
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.372 9.09 3.40
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.5
(Must be less than 96 Hrs)
Page 15 of 61
BMP #8
BMP Type: Flow-Through Planter
Low Fiow Threshoid: 0.SQ2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soil Type Slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 47465 D Steep 1.0 0.05 0.0417 0.03 2373 1979 1424
DMA2 27405 D Steep 0.1 0.05 0.0417 0.03 137 114 82
DMAS 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 2510.275 2094 1506
Note: HMP Sizing Factors per Section 7 of HMP
Page 16 of 61
Orifice #8
(1) Q=Cd x A X (2gH)0.5
(2) A=[%Q2xADMA]/Cdx(2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 is low flow threshold) 10" Ponding t g=32.2
ft/s2
H= 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
30" Storage
J:
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition 02 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
02 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 1.090 0.133 3.25
DMA2 Oceanside D Scrub Moderate 0.212 0.629 0.06? 1.63
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.200 4.87 2.49
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.9
(Must be less than 96 Hrs)
Page 17 of 61
BMP #9
BMP Type: Flow-Through Planter
Low Flow Threshold: 0.SQ2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soii Type Slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 29275 D Steep 1.0 0.05 0,0417 0.03 1464 1221 878
DMA2 19SS9 D Steep 0.1 O.OS 0.0417 0.03 98 82 59
DMAS 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 1562.095 1303 937
Note: HMP Sizing Factors per Section 7 of HMP
Page 18 of 61
Orifice #9
(1) 0=Cd X A X (2gH)0.5
(2) A= f%Q2 X ADMA]/Cd x (2gl 1)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 is low flow threshold)
10" Ponding
g=32.2
ft/s2
H = 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
18" Amended Soil
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 0.6?2 0.082 2.00
DMA2 Oceanside D Scrub Steep 0.244 0.452 0.055 1.35
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.137 3.35 2.06
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.6
(Must be less than 96 Hrs)
Page 19 of 61
BMP #10
BMP Type: Flow-Through Planter
Low Flow Threshold: 0.SQ2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soil Type Slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 514BS D Steep 1.0 0.05 0.0417 0.03 2574 2147 1545
DMA2 29894 D Steep 0.1 0.05 0.0417 0.03 149 125 SO
DMA3 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 2723.72 2272 1634
Note: HMPSizIng Factors per Section 7 of HMP
Page 20 of 61
Orifice #10
(1) Q=Cd X A X (2gH)0.5
(2) A=[%Q2xADMA]/Cdx(2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 Is low flow threshold)
^
10" Ponding
t
g=32.2
ft/s2
H= 1.5
ft
18" Amended Soil 1
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2)
DMAl Oceanside D Scrub Steep 0.244 1.182 0.144 3.52
DMA2 Oceanside D Scrub Steep 0.244 0.686 0.084 2.04
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.228 5.57 2.66
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.S
(Must be less than 96 Hrs)
Page 21 of 61
BMP #11
BMP Type: Flow-Through Planter
Low Fiow Threshoid: 0.502
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soil Type Slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 107760 D Steep 1.0 0.05 0.0417 0.03 5388 4494 3233
DMA2 94208 D Steep 0.1 0.05 0.0417 0.03 471 393 283
DMAS 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 5859.04 4886 3515
Note: HMP Sizing Factors per Section 7 of HMP
Page 22 of 61
Orifice #11
(1) Q=Cd x A X (2gH)0.5
(2) A= [%Q2 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 is low flow threshold)
T
' Ponding
g=32.2
ft/s2
H = 1.5
ft
18" Amended Soil 1
•a' •" JO -I.
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 2.474 0.302 7.37
DMA2 Oceanside D Scrub Steep 0.244 2.163 0.264 6.44
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.566
Tot. Orifice Flow
(cfs)
13.81
Tot. Orifice Area
(in2)
4.19
Orifice Dia
(in)
Drawdown (Hrs) 2.4
(Must be less than 96 Hrs)
Page 23 of 61
BMP #12
BMP Type: Flow-Through Planter
Low Flow Threshoid: 0.SQ2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soil Type Slope Runoff Factor Surface Area Surface Votume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 27704 D steep 1.0 0.05 0,0417 0.03 1385 1155 831
DMA2 13512 D Steep 0.1 0.05 0.0417 0.03 68 56 41
DMA3 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 1452.76 1212 872
Note: HMP Sizing Factors per Section 7 of HMP
Page 24 of 61
Orifice #12
(1) 0=Cd X A X (2gH)0.5
(2) A= [%02 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 is low flow threshold) 10" Ponding t
g=32.2
ft/s2
H = 1.5
ft
18" Amended Soil
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
18"
30" Storage 4r
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 0.636 0.0?8 1.89
DMA2 Oceanside D Scrub Steep 0.244 0.310 0.038 0.92
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.115 2.82 1.89
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.9
(Must be less than 96 Hrs)
Page 25 of 61
BMP #13
BMP Type: Flow-Through Planter
Low Flow Threshold: 0.5Q2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soii Type siope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 32104 D Steep 1.0 0.05 0.0417 0.03 1605 1339 963
DMA2 1S939 D Steep 0.1 0.05 0.0417 0.03 95 79 57
DMAS 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 16S9.SS5 1418 1020
Note: HMP Sizing Factors per Section 7 of HMP
Page 26 of 61
Orifice #13
(1) 0=Cd X A X (2gH)0.5
(2) A=[%Q2xADMAl/Cdx(2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 is low flow threshold)
10" Ponding
g=32.2
ft/s2
H= 1.5
ft
18" Amended Soil
A
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2)
DMAl Oceanside D Scrub Steep 0.244 0.?3? 0.090 2.20
DMA2 Oceanside D Scrub Steep 0.244 0.435 0.053 1.30
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.143 3.49 2.11
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.8
(Must be less than 96 Hrs)
Page 27 of 61
BMP #14
BMP Type: Flow-Through Planter
Low Fiow Threshold: 0.SQ2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP aize
Area (st) Soii Type siope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 19400 D Steep 1.0 0.05 0.0417 0.03 970 809 582
DMA2 21293 D Steep 0.1 0.05 0.0417 0.03 IOS 89 64
DMAS 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Totai 1076.465 898 646
Note: HMP Sizing Factors per Section 7 of HMP
Page 28 of 61
Orifice #14
(1) 0=Cd X A X (2gH)0.5
(2) A= [%02 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 Is low flow threshold)
g=32.2
ft/s2
H= 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
18" Amended Soil
1
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor DMA Area (ac) Orifice Flow-%Q2 Orifice Area (In2)
Soil Type Cover Slope (cfs/ac) (cfs)
DMAl Oceanside D Scrub Steep 0.244 0.445 0.054 1.33
DMA2 Oceanside D Scrub Steep 0.244 0.489 0.060 1.46
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.114 2.78 1.88
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.2
(Must be less than 96 Hrs)
Page 29 of 61
BMP #15
BMP Type: Flow-Through Planter
Low Flow Threshold: 0.5Q2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soil Type Slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 18215 D Steep 1.0 0.05 0.0417 0.03 911 760 546
DMA2 12359 D Steep 0.1 0.05 0.0417 0.03 62 52 37
DMAS 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 972.545 811 584
Note: HMP Sizing Factors per Section 7 of HMP
Orifice #15
(1) 0=Cd X A x (2gH)0.5
(2) A= [%Q2 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 is low flow threshold)
10" Ponding
t g=32.2
ft/s2
H = 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
18" Amended Soil
18"
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 0.418 0.051 1.25
DMA2 Oceanside D Scrub Steep 0.244 0.284 0.035 0.85
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.086 2.09 1.63
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.6
(Must be less than 96 Hrs)
Page 31 of 61
BMP #16
BMP Type: Flow-Through Planter
Low Flow Threshold: 0.502
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soil Type Slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 3S011 D Steep 1.0 0.05 0.0417 0.03 ISOl 1585 1140
DMA2 40157 D Steep 0.1 O.OS 0.0417 0.03 201 167 120
DMAS 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 2101.335 1753 1261
Note: HMP Sizing Factors per Section 7 of HMP
Page 32 of 61
Orifice #16
(1) Q=Cd X A X (2gH)0.5
(2) A=[%02xADMA]/Cdx(2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation {%Q2 is low flow threshold)
g=32.2
ft/s2
H = 1.5
ft
10" Ponding
18" Amended Soil
1
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
30" Storage
J:
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 0.873 0.106 2.60
DMA2 Oceanside D Scrub Steep 0.244 0.922 0.112 2.75
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.219
Tot. Orifice Flow
(cfs)
5.35
Tot. Orifice Area
(in2)
2.61
Orifice Dia
(in)
Drawdown (Hrs) 2.2
(Must be less than 96 Hrs)
Page 33 of 61
BMP #17
BMP Type: Flow-Through Planter
Low Fiow Threshoid: 0.502
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soil Type slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 33904 D Steep 1.0 0.05 0.0417 0.03 1695 1414 1017
DMA2 26106 D Steep 0.1 0.05 0.0417 0.03 131 109 78
DMA3 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 1825.73 1523 loss
Note: HMP Sizing Factors per Section 7 of HMP
Page 34 of 61
Orifice #17
(1) 0=Cd X A X (2gH)0.5
(2) A= [%Q2 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 is low flow threshold)
^
10" Ponding
g=32.2
ft/s2
H = 1.5
ft
18" Amended Soil
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 0.??8 0.095 2.32
DMA2 Oceanside D Scrub Steep 0.244 0.599 0.0?3 1.79
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.168 4.10 2.29
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.5
(Must be less than 96 Hrs)
Page 35 of 61
BMP #18
BMP Type: Flow-Through Planter
Low Fiow Threshold: 0.5Q2
Rain Gauge: Oceanside
HMP sizing Factors Minimum BMP Size
Area (sf) Soil Type slope Runoff Factor Surface Area Surface Volume Subsurface Votume Surface Area Surface Volume Subsurface Volume
DMAl 51924 D steep 1.0 0,05 0.0417 0,03 2596 2165 1558
DMA2 31637 D Steep 0.1 O.OS 0.0417 0.03 158 132 95
DMAS 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 2754.385 2297 1653
Note: HMP Sizing Factors per Section 7 of HMP
Page 36 of 61
Orifice #18
(1) Q=Cd X A X (2gH)0.5 Orifice Discharge Equation
(2) A= [%Q2 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Area Equation (%Q2 is low flow threshold)
g=32.2
ft/s2
II = 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
^
10" Ponding t 18" Amended Soil V.
A
30" Storage ,
18"
A.
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 1.192 0.145 3.55
DMA2 Oceanside D Scrub Steep 0.244 0.726 0.089 2.16
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.234 5.71 2.70
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.?
(Must be less than 96 Hrs)
Page 37 of 61
BMP #19
BMP Type: Flow-Through Planter
Low Flow Threshold: 0.5Q2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soil Type Slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl S4870 D Steep 1.0 0.05 0,0417 0.03 3244 2705 1946
DMA2 104043 D Steep 0.1 0.05 0.0417 0.03 520 434 312
DMAS 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 37S3.71S 3139 22SS
Note: HMP Sizing Factors per Section 7 of HMP
Page 38 of 61
Orifice #19
(1) Q=Cd X A X (2gl 1)0.5 Orifice Discharge Equation
(2) A= [%02 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Area Equation (%Q2 is low flow threshold)
g=32.2
ft/s2
H= 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
¥
10" Ponding t 18" Amended Soil
T
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2)
DMAl Oceanside D Scrub Steep 0.244 1.489 0.182 4.44
DMA2 Oceanside D Scrub Steep 0.244 2.388 0.291 7.12
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.473 11.55 3.84
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs)
(Must be less than 96 Hrs)
Page 39 of 61
BMP #20
BMP Type: Flow-Through Planter
Low Fiow Threshold: 0.SQ2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soii Type Siope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 48693 D Steep 1.0 0.05 0,0417 0.03 2435 2030 1461
DMA2 31236 D Steep 0.1 0.05 0,0417 0.03 156 130 94
DMA3 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 2590.83 2161 1554
Note: HMP Sizing Factors per Section 7 of HMP
Page 40 of 61
Orifice #20
(1) Q=Cd X A X (2gH)0.5 Orifice Discharge Equation
(2) A= [%Q2 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Area Equation (%Q2 is low flow threshold)
g=32.2
ft/s2
M= 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
18" Amended Soil
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor DMA Area (ac) Orifice Flow - %Q2 Orifice Area (in2)
Soil Type Cover Slope (cfs/ac) (cfs)
DMAl Oceanside D Scrub Steep 0.244 1.118 0.136 3.33
DMA2 Oceanside D Scrub Steep 0.244 0.?1? 0.08? 2.14
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.224 5.47 2.64
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.?
(Must be less than 96 Hrs)
Page 41 of 61
BMP #21
BMP Type: Flow-Through Planter
Low Fiow Threshoid: 0.502
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soil Type Slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 52221 D steep 1.0 0,05 0.0417 0.03 2611 2178 1567
DMA2 34843 D Steep 0.1 0,05 0.0417 0.03 174 145 105
DMAS 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 2785.265 2323 1671
Note: HMP Sizing Factors per Section 7 of HMP
Orifice #21
(1) Q=Cd x A X (2gH)0.5
(2) A= [%Q2 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 Is low flow threshold)
10" Ponding
g=32.2
ft/s2
H= 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
18" Amended Soil E'
A ^
30" Storage
J:
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2)
DMAl Oceanside D Scrub Steep 0.244 1.199 0.146 3.57
DMA2 Oceanside D Scrub Steep 0.244 0.800 0.098 2.38
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.244 5.95 2.75
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.6
(Must be less than 96 Hrs)
Page 43 of 61
BMP #22
BMP Type: Flow-Through Planter
Low Flow Threshoid: 0.5Q2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soil Type siope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 79654 D Steep 1.0 0.05 0.0417 0.03 3983 3322 2390
DMA2 47488 D Steep 0.1 0.05 0,0417 0.03 237 198 142
DMA3 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Totai 4220.14 3520 2532
Note: HMP Sizing Factors per Section 7 of HMP
Orifice #22
(1) 0=Cd X A X (2gH)0.5
(2) A= [%Q2 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 is low flow threshold)
g=32.2
ft/s2
H= 1.5
ft
^
10" Ponding
18" Amended Soil
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
30" Storage
Flow Conh-ol Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor DMA Area (ac) Orifice Flow - %Q2 Orifice Area (in2)
Soil Type Cover Slope (cfs/ac) (cfs)
DMAl Oceanside D Scrub Steep 0.244 1.829 0.223 5.45
DMA2 Oceanside D Scrub Steep 0.244 1.090 0.133 3.25
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.356 8.70 3.33
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.?
(Must be less than 96 Hrs)
Page 45 of 61
BMP #23
BMP Type: Flow-Through Planter
Low Fiow Threshold: 0.502
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP jize
Area (sf) Soil Type Slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 42202 D Steep 1.0 0.05 0.0417 0.03 2110 1760 1266
DMA2 19295 D Steep 0.1 0.05 0.0417 0.03 96 SO 58
DMAS 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 2205.575 1840 1324
Note: HMP Sizing Factors per Section 7 of HMP
Page 46 of 61
Orifice #23
(1) Q=Cd X A X (2gH)0.5
(2) A= [%02 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 is low flow threshold)
10" Ponding
g=32.2
ft/s2
11= 1.5
ft
8" Amended Soil K^-^S^^^c
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
30" Storage
^
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition 02 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
02 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 0.969 0.118 2.89
DMA2 Oceanside D Scrub Steep 0.244 0.443 0.054 1.32
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.172 4.21 2.31
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 3.0
(Must be less than 96 Hrs)
Page 47 of 61
BMP #24
BMPType: Flow-Through Planter
Low Flow Threshold: 0.502
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP 5ize
Area (sf) Soil Type Slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 116378 D steep 1.0 O.OS 0.0417 0.03 581S 4853 3491
DMA2 10259S D Steep 0.1 0,05 0.0417 0.03 513 428 308
DMAS 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 6331.875 5281 3799
Note: HMP Sizing Factors per Section 7 ot HMP
Page 48 of 61
Orifice #24
(1) Q=Cd X A x (2gH)0.5
(2) A= [%Q2 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 is low flow threshold)
g=32.2
ft/s2
H= 1.5
ft
10" Ponding
18" Amended Soil
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
30" Storage
J:^ .
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2)
DMAl Oceanside D Scrub Steep 0.244 2.6?2 0.326 7.96
DMA2 Oceanside D Scrub Steep 0.244 2.355 0.287 7.02
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.613 14.98 4.37
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.4
(Must be less than 96 Hrs)
Page 49 of 61
BMP #25
BMP Type: Flow-Through Planter
Low Flow Threshold: 0.502
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soii Type Slope Runoff Factor Surface Area Surface Volume Subsurface Votume Surface Area Surface Volume Subsurface Volume
DMAl 111757 D Steep 1.0 0.05 0,0417 0,03 5588 4660 3353
DMA2 92195 D Steep 0.1 0.05 0,0417 0.03 461 384 277
DMAS 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 6048.825 5045 3629
Note: HMP Sizing Factors per Section 7 of HMP
Page 50 of 61
Orifice #25
(1) 0=Cd X A X (2gH)0.5
(2) A= [%Q2 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 is low flow threshold)
^
10" Ponding t
g=32.2
ft/s2
H= 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
18" Amended Soil »7
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2)
DMAl Oceanside D Scrub Steep 0.244 2.566 0.313 7.64
DMA2 Oceanside D Scrub Steep 0.244 2.11? 0.25S 6.31
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.571 13.95 4.21
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.5
(Must be less than 96 Hrs)
Page 51 of 61
BMP #26
BMP Type: Flow-Through Planter
Low Fiow Threshold: 0.502
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soil Type Slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 100996 D Steep 1.0 0.05 0.0417 0.03 5050 4212 3030
DMA2 68194 D Steep 0.1 0.05 0.0417 0,03 341 284 205
DMA3 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 5390.77 4496 3234
Note: HMP Sizing Factors per Section 7 of HMP
Page 52 of 61
Orifice #26
(1) 0=Cd X A X (2gH)0.5 Orifice Discharge Equation
(2) A= [%Q2 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Area Equation (%Q2 is low flow threshold)
¥
10" Ponding
t g=32.2
ft/s2
H = 1.5
ft
18" Amended Soil 1
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
30" Storage
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 2.319 0.2S3 6.91
DMA2 Oceanside D Scrub Steep 0.244 1.566 0.191 4.66
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.474 11.57 3.84
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.6
(Must be less than 96 Hrs)
Page 53 of 61
BMP #27
BMPType: Flow-Through Planter
Low Flow Threshold: 0.5Q2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (st) Soii Type Slope Runoff Factor Surface Area Surface Volume Subsurface Votume Surface Area Surface Volume Subsurface Volume
DMAl S16S9 D Steep 1.0 0.05 0.0417 0.03 4084 3406 2451
DMA2 81875 D Steep 0.1 0.05 0.0417 0,03 409 341 246
DMAS 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Total 44S3.S25 3748 2596
Note: HMP Sizing Factors per Section 7 of HMP
Page 64 of 61
Orifice #27
(1) 0=Cd X A X (2gH)0.5 Orifice Discharge Equation
(2) A= [%Q2 x ADMAl/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Area Equation (%Q2 is low flow threshold)
¥
10" Ponding t g=32.2
ft/s2
H= 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
18" Amended Soil
J 18"
30" Storage i-
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 1.875 0.229 5.59
DMA2 Oceanside D Scrub Steep 0.244 1.880 0.229 5.60
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.458 11.19 3.77
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.3
(Must be less than 96 Hrs)
Page 55 of 61
BMP #28
BMPType: Flow-Through Planter
Low Flow Threshoid: 0.5Q2
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP Size
Area (sf) Soii Type siope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 3071S D steep 1.0 0,05 0,0417 0,03 1536 1281 921
DMA2 1S873 D Steep 0.1 0.05 0.0417 0.03 94 79 57
DMAS 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA9 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Totai 1630.115 1360 S78
Note: HMP Sizing Factors per Section 7 of HMP
Page 56 of 61
Orifice #28
(1) Q=Cd X A X (2gH)0.5
(2) A= [%Q2 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 is low flow threshold)
• ¥
10" Ponding t
g=32.2
ft/s2
H = 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
18" Amended Soil
18"
30" Storage
i
Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (In2)
DMAl Oceanside D Scrub Steep 0.244 0.705 0.0S6 2.10
DMA2 Oceanside D Scrub Steep 0.244 0.433 0.053 1.29
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.139 3.39 2.08
Tot. Orifice Flow Tot. Orifice Area Orifice Dia
(cfs) (in2) (in)
Drawdown (Hrs) 2.7
(Must be less than 96 Hrs)
Page 5? of 61
BMP #29
BMP Type: Flow-Through Planter
Low Flow Threshold: 0.502
Rain Gauge: Oceanside
HMP Sizing Factors Minimum BMP size
Area (sf) Soii Type Slope Runoff Factor Surface Area Surface Volume Subsurface Volume Surface Area Surface Volume Subsurface Volume
DMAl 68345 D steep 1.0 0,05 0.0417 0.03 3417 2850 2050
DMA2 S9326 D steep 0.1 0,05 0.0417 0.03 347 289 208
DMA3 0 0 0 0 0 0
DMA4 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMA6 0 0 0 0 0 0
DMA7 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAS 0 0 0 0 0 0
DMAIO 0 0 0 0 0 0
BMP Totai 3763.88 3139 2258
Note: HMPSizIng Factors per Section 7 of HMP
Page 58 of 61
Orifice #29
(1) Q=Cd x A x (2gH)0.5
(2) A= [%Q2 X ADMA]/Cd x (2gH)0.5
Cd= 0.6
dimensionless
Orifice Discharge Equation
Orifice Area Equation (%Q2 is low flow threshold)
10" Ponding
t
g=32.2
ft/s2
H = 1.5
ft
Deviation from this standard outlet structure design will require separate external calculations
to verify hydraulic adequacy.
Q2s provided below (see San Diego BMP Sizing Calculator Methodology, Sec. 1.6, Table 1-6)
Cd = Orifice Discharge Coefficient
g = Gravitational Acceleration
H = Effective Head Above Orifice (ft)
1.5' (Typical for Bioretention and Flow-Through Planter)
3.5' (Typical for Cistern)
3.2' (Typical for Vault)
A = Cross Sectional Area of Orifice
18" Amended Soil
18"
A_ 30" Storage
i Flow Control Orifice
Bioretention / Flow-Through Planter
Rain Gage Existing Condition Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2) Rain Gage
Soil Type Cover Slope
Q2 Sizing Factor
(cfs/ac)
DMA Area (ac) Orifice Flow - %Q2
(cfs)
Orifice Area (in2)
DMAl Oceanside D Scrub Steep 0.244 1.569 0.191 4.67
DMA2 Oceanside D Scrub Steep 0.244 1.592 0.194 4.74
DMA3 0 0.000 0.000 0.00
DMA4 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA6 0 0.000 0.000 0.00
DMA? 0 0.000 0.000 0.00
DMAS 0 0.000 0.000 0.00
DMA9 0 0.000 0.000 0.00
DMAIO 0 0.000 0.000 0.00
0.386
Tot. Orifice Flow
(cfs)
9.42
Tot. Orifice Area
(in2)
3.46
Orifice Dia
(in)
Drawdown (Hrs) 2.3
(Must be less than 96 Hrs)
Page 59 of 61
Rain Gauge Map
RXPT.ANATTON
Precipitation Contours
Lake Wohlford Basin
Lindbergh Basin
4^ Oceanside Basin
Brown AND
Caldwell RAINFALL BASIN MAP
SAN DIEGO HMP
Page 60 of 61
Sizing Factors
Table 7-1. Sizing Factors for Bioretention Facilities
Lower Flow Threshold Soil Group Slope Rain Gauge A V1 V2
0.5Q2 A Flat Lindbergti 0.06 0.05 N/A
0.5Q2 A Moderate Lindbergti 0.055 0.0458 N/A
0.5Q2 A Steep Lindbergti 0.045 0.0375 N/A
0.5Q2 B Flat Lindbergh 0.093 0.0771 N/A
0.5Q2 B Moderate Lindbergh O.OSS 0.070S N/A
0.5Q2 B Steep Lindbergh 0.065 0.0542 N/A
0.5Q2 0 Flat Lindbergh 0.1 0.0833 0.06
0.5Q2 C Moderate Lindbergh 0.1 0.0833 0.06
0.5Q2 C Steep Lindbergh 0.0?5 0.0625 0.045
0.5Q2 D Flat Lindbergh 0.08 0.0667 0.048
0.5Q2 D Moderate Lindbergh O.OS 0.066? 0.048
0.5Q2 D Steep Lindbergh 0.06 0.05 0.036
0.5Q2 A Flat Oceanside 0.0? 0.05S3 N/A
0.5Q2 A Moderate Oceanside 0.065 0.0542 N/A
0.5Q2 A Steep Oceanside 0.06 0.05 N/A
0.5Q2 8 Flat Oceanside 0.098 0.0S13 N/A
0.5Q2 B Moderate Oceanside 0.09 0.075 N/A
0.5Q2 B Steep Oceanside 0.075 0.0625 N/A
0.5Q2 C Flat Oceanside 0.075 0.0625 0.045
0.5Q2 C Moderate Oceanside 0.075 0.0625 0.045
0.5Q2 C Steep Oceanside 0.06 0.05 0.036
0.5Q2 D Flat Oceanside 0.065 0.0542 0.039
0.5Q2 D Moderate Oceanside 0.065 0.0542 0.039
0.5Q2 D Steep Oceanside 0.05 0.0417 0.03
0.5Q2 A Flat Lake Wohlford 0.05 0.041? N/A
0.5Q2 A Moderate Lake Wohlford 0.045 0.0375 N/A
0.5Q2 A Steep Lake Wohlford 0.04 0.0333 N/A
0.5Q2 B Flat Lake Wohlford 0.048 0.0396 N/A
0.5Q2 B Moderate Lake Wohlford 0.045 0.0375 N/A
0.5Q2 B Steep Lake Wohlford 0.04 0.0333 N/A
0.5Q2 C Flat Lake Wohlford 0.065 0.0542 0.039
0.5Q2 C Moderate Lake Wohlford 0.065 0.0542 0.039
0.5Q2 C Steep Lake Wohlford 0.05 0.0417 0.03
0.5Q2 D Flat Lake Wohlford 0.055 0.045S 0.033
0.5Q2 D Moderate Lake Wohlford 0.055 0.045S 0.033
0.5O2 D Steep Lake Wohlford 0.045 0.0375 0.02?
Page 61 of 61
JUL 0
' ENGINEER