HomeMy WebLinkAboutCT 13-05; State Street Townhomes; Tentative Map (CT) (6)STATE STREET TOWNHOMES
PRELIMINARY STORM WATER MANAGEMENT PLAN
(PRIORITY PROJECT)
CARLSBAD, SAN DIEGO COUNTY, CALIFORNIA
Prepared For:
Intracorp Companies
4041 MacArthur Blvd., Suite 250
Newport Beach, CA 92660
Prepared By:
CD NSU LYING
A ^g^^BI Company
14725 Alton Pkwy
Irvine, CA 92618
Contact Person:
Scott P, Gilbert, P.E.
February 2014
JN 137092
RECEIVED
FEB 0 7 20^
CITY OF CARLSBAD
PLANNING DIViSION
h:\pdata\137092\admin\reports\swmp\preliminaryswmp_2014-01-31.cloc
TABLE OF CONTENTS
Section 1: Purpose and Scope 3
Section 2: Project Information 4
2.1 Project Description 5
2.2 Project Activities 6
Section 3: Water Quality Pollutants of Concern 7
3.1 Potential Pollutants 7
3.2 Primary Pollutants of Concern 8
Section 4: Water Quality Conditions of Concern 9
Section 5: Standard Stormwater Requirements 1
5.1 Minimize Impervious Surfaces 1
5.2 Disconnect Impervious Discharges 1
5.3 Conserve Natural Areas 1
5.4 Stenciling Inlets and Signage 1
5.5 Landscape Design 1
5.6 Water Efficient Landscaping 1
5.7 Protect Slopes and Channels 1
5.8 Trash Receptacles 12
5.9 Material Storage Areas 12
Section 6: BMP Design Calculations 13
6.1 BMP Design Sizing 13
6.2 Relative Effectiveness of Project Treatment Facilities 18
Section 7: BMP Maintenance Provisions 19
7.1 Maintenance Responsibility 19
7.2 BMP Maintenance Matrix 19
List of Exhibits
Exhibit 1 - Proposed SWMP Exhibit
Exhibit 2 - Existing Drainage Exhibit
List of Appendices
Appendix A: Stormwater Standards Questionaire (E-34)
Appendix B: BMP Fact Sheets
Appendix C: Proprietary BMP Manufacturer Information
Sfafe Sfreef Townhomes - Carlsbad, CA
Preliminary SWMP
SECTION 1: PURPOSE AND SCOPE
The City of Carlsbad's Storm Water Management and Discharge Control Ordinance
(Carlsbad Municipal Code Chapter 15,12) requires all development permit applications to
complete the storm water standards questionnaire (E-34). The purpose ofthe questionnaire
is to determine what type of storm water requirements the project must meet. The proposed
Project is considered a significant redevelopment since it represents a redevelopment
Project replacing 5,000 SF or more of impervious surface over a site of more than 10,000
SF of impervious surface. Therefore, this project is a Priority Development Project. The
associated Stormwater Standards Questionnaire (E-34) is included in Appendix "A",
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SECTION 2: PROJECT INFORMATION
Project Name State Street Townhomes
Application Number(s) TBD
Project Address 2539, 2541,2551, 2577, & 2589 State Street, Carlsbad, CA
Assessor Parcel Number(s) 155-200-07, 203-054-19,20,21,22
Total Project Area 1.89 AC (gross) /1.86 AC (net) 81,021 Square Feet
Proposed Project Description and
Land Use High Density Residential (Attached)
Redevelopment Project that
Creates or Replaces 5,000 square
feet of Impervious Surface
• Not
Applicable
^ Increases or
Replaces >50%
of Pre-Project
Impervious
Surface
U Increases or
Replaces <50%
of Pre-Project
Impervious
Surface
Project Disturbed Area 1.86 Acres 81,021 Square Feet
Predevelopment Impervious Area 1.7 Acres 74,052 Feet
Proposed Impervious Area 1.13 Acres 49,306 Square Feet
Proposed Pervious Area 0.73 Acres 31,715 Square Feet
Project Hydrologic Unit Watershed ^ Cadsbad 904.00 - Buena Vista Lagoon 904.21
City of Carlsbad Drainage Basin ^A • B • c • D
Project Hydrologic Soil Group lElA • B • c • D
Number of Discharge Locations 2 Location(s)
Required to Implement HMP • Yes 1^ No*
Number of HMP Compliance Points 0 Location(s)
* Project is tributary to existing City storm drain that outlets into tidally influenced Buena
Vista Lagoon
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2,1 Project Description
The proposed Project site is located along State Street, approximately 650 feet south ofthe
intersection of State Street and Carlsbad Blvd/Coast Highway, in the City of Carlsbad,
California, and is adjacent to the San Diego Northern Railroad right of way which makes up
its western boundary. Today, the site encompasses approximately 1.8 acres of existing
commercial/industrial development spread across 6 existing lots; this is proposed to be
converted into a residential development with 47 townhomes, and associated drive aisles,
parking, and common areas.
According to the Carlsbad Drainage Master Plan prepared in July of 2008 this Project is
located within "Basin A" which "encompasses all areas in the City that drain into the Pacific
Ocean via the Buena Vista Creek and the Buena Vista Lagoon."
The existing Project site consists of multiple existing buildings, parking areas, and drive
aisles and generally drains from north east to south west at a slope of roughly 2-4%
across the site. There is a large 66" City of Carlsbad storm drain that bisects the site;
however, there does not appear to be any storm drain connections to the Project site
itself, and there are no existing stormwater BMPs on the Property The existing runoff
sheet flows off the site into the San Diego Northern Railroad property.
Figure 1 - Vicinity Map
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2.2 Project Activities
This redevelopment Project will result in the demolition of all existing buildings, paving,
and utilities currently on the Property, the site will then be re-graded for creation of the
proposed 47 townhomes, associated drive aisles, and common areas.
In its current condition, the Project site discharges surface runoff in roughly 4 locations.
The northern most 2 locations sheet flow across the Property line into the San Diego
Northern Railroad Property, whereas the 2 locations to the south discharge into the
existing City alley where it ultimately enters a catch basin in the center of the alley cul-
de-sac that is connected to a 66" City of Cadsbad storm drain that bisects the property.
The existing drainage patterns are shown on Exhibit 1 - Existing Site Drainage.
The proposed Project will concentrate these existing discharge points, resulting in only 2
discharge points, both of which will connect to the existing 66" storm drain that bisects
the Project site, and ultimately outlets directly into Buena Vista Lagoon, approximately
350 feet downstream of the Project.
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SECTION 3: WATER QUALITY POLLUTANTS OF CONCERN
3.1 Potential Pollutants
The State Street Townhomes project falls in the "Attached Residential" category as
highlighted in Table 3-1. Although many constituents are generally anticipated for projects
in this category the proposed project is not expected to generate significant amounts of
pollutants,
Anticipated Pollutants
P Potential Pollutants General Pollutant Categories
Project Categories Sediments Nutrients Heavy Metals Organic Compounds Trash and Debris Oxygen-Demanding Substances Oils and Grease Bacteria and Viruses Pesticides Detached Residential • •
Atta'ched^Be^eifkl^l k'^K • •
p(5) • p(3) p(5) Commercial (>100,000 sf) pd) pd) p(2) p(5) • p(3) p(5)
Heavy industry / industrial • • • •
Auto Repair Shops y^(4)(5) • •
Restaurants • • •
Hillside Development
(>5,000 sf)
Parking Lots pd) pd) pd) pd)
Retail Gasoline Outlets • •
Streets, Highways, and
Freeways pd) • p(5) •
(1) A potential pollutant if landscaping exists on-site;
(2) A potential pollutant ifthe project includes uncovered parking areas;
(3) A potential pollutant if land use involved food or animal waste products;
(4) Including petroleum hydrocarbons;
(5) Including solvents.
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Preliminary SWMP
Potential pollutants of concern associated with this project category include:
Sediments (since there will be landscaped areas on site);
Nutrients (since there will be landscaped areas on site);
Organic Compounds (since dog walking is possible, and there are small parking areas);
Litter and trash collecting in the drainage systems;
Oxygen-demanding substances including biodegradable organic material and chemicals
(since there will be landscaped areas on site);
Oils, grease, and other hydrocarbons emanating from paved areas on the site;
Bacteria and Viruses (since dog walking is possible);
Pesticides used to control nuisance landscape growth.
3.2 Primary Pollutants of Concern
The project site is located in the 14,437-acre (22.6 square mile) Buena Vista Creek
Hydrologic Area (HA 904.2), which is part ofthe Carlsbad Hydrologic Unit (HU 904.00).
The most immediate receiving waters for the project site are the Buena Vista Lagoon and
the Pacific Ocean. According to the California 2006 303(d) list published by the San Diego
Regional Water Quality Control Board (RWQCB Region 9), Buena Vista Lagoon is impaired
by bacteria indicators, nutrients and sedimentation. The Pacific Shoreline, located
approximately half a mile downstream, is listed as impaired by bacteria indicator. Refer to
Table 3-2 for the impairments of the downstream waterbodies. It is highly unlikely that the
potential pollutants from the project site would have a significant detrimental effect on the
listed impairments downstream, but the impairments should be kept in mind when
determining the appropriate program of BMPs. Table 3-2 summarizes the receiving waters
and their classification by the RWQCB Region 9.
Table 3-2 Summary of Receiving Surface Waters
Receiving Water Hydrologic
Unit Code
Approximate
Distance From
Site
303(d)
Impairment(s)
Buena Vista Lagoon 904.21 0 mi
Sedimentation,
Bactena Indicators,
Nutrients
Pacific Ocean Shoreline (Buena Vista Creek) 904.21 0.5 mi Bacteria Indicators
Receiving waters downstream of the project site are impaired by bacteria indicators,
nutrients, and sedimentation as shown in Table 3-2. The proposed project activities are
anticipated to produce sediment, nutrients, organic compounds, trash debris, pesticides and
oil and grease, as shown in Table 3-1. Therefore, the primary pollutants of concern
associated with the project are nutrients, and sediment. The remaining anticipated pollutants
are considered secondary pollutants of concern.
Sfafe Sfreef Townhomes - Cadsbad, CA
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SECTION 4: WATER QUALITY CONDITIONS OF CONCERN
11.0 Hydromodification Management Plan (HMP) Applicability Determination
Figure 6-1. HMP Applicability Determination
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Node Component Response Response
1 Priority Development Project 13 Yes - Go to Node 2 • No - Exempt
2 Proper Energy Dissipation ^ Yes - Go to Node 3 Intentionally left blank
Go to Node 3
3 Increase Impervious Area • Yes - Go to Node 4 IEI No - Go to Node 5
4 Increase Unmitigated Peak
Flows to Any Outlet Location • Yes - Go to Node 5 K No - Exempt
5 Direct Discharge to an Exempt
System • Yes - Exempt • No - Go to Node 6
6 Direct Discharge to a Tidally
Influenced Lagoon Area ^ Yes - Exempt • No - Go to Node 7
7 Direct Discharge to Stabilized
Conveyance to Exempt System • Yes - Go to Node 8 • No - Go to Node 9
8
Does Stabilized Conveyance
Have Capacity to Convey
Ultimate QIO
• Yes - Exempt • No - Go to Node 9
g Discharge to Highly Urbanized
Area • Yes - Exempt • No-Go to Node 10
10 Urban Infill Project Discharging
to Stabilized Conveyance • Yes-Goto Node 11 • No - HMP Controls Required
Goto Node 14
11 Determine Domain of Analysis • Yes-Go to Node 12 Intentionally Left Blank
Does Not Apply to Node 11
12
Stabilized Conveyance Extends
Beyond Domain of Analysis and
Eventually Discharges to LOW
Susceptibility Stream
• Yes-Goto Node 13 • No - HMP Controls Required
Go to Node 14
13
Cumulative Future Impacts
Represent <3% Impervious Area
Increase
• Yes - Exempt • No - HMP Controls Required
Go to Node 14
14 Go to HMP Figure 6-2 Mitigation Criteria and Implementation
Comments:
Project Is tributary to an existing City storm drain that discharges directly to Buena Vista Lagoon
approximately 350 feet downstream of the Project Site.
10
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Preliminary SWMP
SECTION 5: STANDARD STORMWATER REQUIREMENTS
standard Stormwater Requirements involve incorporating the following applicable
techniques into the project design:
5.1 Minimize Impervious Surfaces
Using excessive impervious surfaces tend to increase the potential of pollutant contact
with urban runoff and increase runoff. The overall project decreases the area of
pollutant-generating impervious surfaces versus what exists today. The existing site has
no landscaping and is roughly 92% impervious, whereas the proposed site will be
approximately 61% impervious. This reduction in imperviousness has been
accomplished by creating new landscaped common areas, as well as utilizing permeable
pavers in all project drive aisles.
5.2 Disconnect Impervious Discharges
The proposed Project Site will utilize a combination of flow-through planters (for
buildings) and bio-retention (drive aisles and common areas) to provide water quality
treatment,
5.3 Conserve Natural Areas
The existing site is fully developed with roughly 92% being impervious. There are no
natural areas within the Project site to conserve. However, the proposed Project will
significantly increase the amount of pervious surface.
5.4 Stenciling Inlets and Signage
All new storm drain grate inlets constructed as part of this project will be signed with the
message indicating they drain to the ocean, as directed by the City. The project also
proposes signs with descriptive language prohibiting dumping into the Buena Vista Lagoon.
5.5 Landscape Design
Efficient landscape design can be an effective source-control to prevent pollution in storm
water and dry-weather flows. The proposed site landscaping will comply with this
requirement.
5.6 Water Efficient Landscaping
Landscape designs that group plants with similar water requirements can reduce excess
irrigation runoff and promote surface infiltration. The proposed site landscaping irrigation will
comply with this requirement.
5.7 Protect Slopes and Channels
The project runoff is self-contained within the Project site, and outlets to storm drain.
This configuration will prevent adjacent properties from any effect of storm water runoff
11
Sfafe Sfreef Townhomes - Cadsbad, CA
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from this Project Site.
5.8 Trash Receptacles
Each unit will have private trash bins to be stored in the garage. These bins will have lids,
and only be outside of the garage on trash pickup days. Common areas will have trash
receptacles, and will be equipped with lids that prevent contact with rainfall.
5.9 Material Storage Areas
No material storage will take place at the proposed project site.
12
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Preliminary SWMP
SECTION 6: BMP DESIGN CALCULATIONS
6,1 BMP Design Sizing
The following tables detail the proposed BMP sizing calculations:
Tabulation of Areas Draining to Flow Through Planter DMA-1
Surface Type Area (ft^) Runoff
Factor
Area x Runoff
Factor
Roofs 5204 1.0 5204
Concrete/Asphalt 1.0 0
Grouted unit Pavers 1.0 0
Solid Unit Pavers 0.2 0
Pervious concrete 0.1 0
Porous Asphalt 0.1 0
Crushed Aggregate 0,1 0
Turfblock 0,1 0
Amended, Mulched soil 0.1 0
Landscape Areas 52 0.1 5
Subtotal 5209
IMP Sizing Faaor (SUSMP Table 4-6) 0.04
Minimum IMP Area 20S
t Praposed IMP Area (Water Quality Tr^Gne
Bioretention Configuration PLANTER
Total Area of DMA 5256
13
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Preliminary SWMP
Tabulation of Areas Draining to Flow Through Planter DMA-2
Surface Type Area (ft^) Runoff
Factor
Area x Runoff
Factor
Roofs 5907 1.0 5907
Concrete/Asphalt 1.0 0
Grouted unit Pavers 1.0 0
Solid Unit Pavers 0.2 0
Pervious concrete 0.1 0
Porous Asphalt 0.1 0
Crushed Aggregate 0.1 0
Turfblock 0.1 0
Amended, Mulched soil 0.1 0
Landscape Areas 316 0.1 32
Subtotal 5939
IMP Sizing Factor (SUSMP Table 4-6) 0.04
Minimum IMP Area 238
•Vf i^'Propt^s"^ IMP Area (Water QualitifWto^^^^^
Bioretention Configuration PLANTER
Total Area of DMA 6223
Tabulation of Areas Draining to a Katchall DMA-3
Surface Type Area (ft^) Runoff
Factor
Area x Runoff
Factor
Roofs 6275 1.0 6275
Concrete/Asphalt 1.0
Grouted unit Pavers 1.0 0
Solid Unit Pavers 0.2 0
Pervious concrete 0.1 0
Porous Asphalt 0.1
Crushed Aggregate 0.1 0
Turfblock 0.1 0
Amended, Mulched soil 0.1 0
Landscape Areas 156 0.1 16
Subtotal 6291
IMP Sizing Factor (SUSMP Table 4-6) 0.04
Minimum IMP Area 252
f ' Proposed IMP Area (Water Quality Treatment Only)
Bioretention Configuration PLANTER
Total Area of DMA 6432
14
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Tabulation of Areas Draiiiilgto a Bioretention IMP
Surface Type Area (ft') Runoff
Factor
Area x Runoff
Factor
Roofs 5385 1.0 5385
Concrete/Asphalt 1.0 0
Grouted unit Pavers 1.0 0
Solid Unit Pavers 0.2 0
Pervious concrete 0.1 0
Porous Asphalt 0.1 0
Crushed Aggregate 0.1 0
Turfblock 0.1 0
Amended, Mulched soil 0.1 0
Landscape Areas 156 0.1 16
Subtotal 5401
IMP Sizing Factor (SUSMP Table 4-6) 0.04
Minimum IMP Area 216
Propbsed IMP Area (Water Quality Trieatmieht Only)
Bioretention Configuration PLANTER
Total Area of DMA 5541
Tabulation of Areas Draining to a Bioretention IMP DMA-5
Surface Type Area (ft') Runoff Area x Runoff Surface Type Area (ft') Factor Factor
Roofs 4517 1.0 4517
Concrete/Asphalt 1.0 0
Grouted unit Pavers 1.0 0
Solid Unit Pavers 0.2 0
Pervious concrete 0.1 0
Porous Asphalt 0.1 0
Crushed Aggregate 0,1 0
Turfblock 0.1 0
Amended, Mulched soil 0.1 0
Landscape Areas 21 0.1 2
Subtotal 4519
IMP Sizing Factor (SUSMP Table 4-6) 0.04
Minimum IMP Area 181
Proposed IMP Area (Water Quality Treatment Only) 230
Bioretention Configuration PLANTER
Total Area of DMA 4538
15
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Preliminary SWMP
Tabulation of Areas Draining to Flow Through Planter DMA-6
Surface Type Area (ft') Runoff
Factor
Area x Runoff
Factor
Roofs 3918 1.0 3918
Concrete/Asphalt 1102 1.0 1102
Grouted unit Pavers 1.0 0
Solid Unit Pavers 3629 0.2 726
Pervious concrete 0,1 0
Porous Asphalt 0.1 0
Crushed Aggregate 0.1 0
Turfblock 0.1 0
Amended, Mulched soil 0.1 0
Landscape Areas 1248 0,1 125
Subtotal 5870
IMP Sizing Factor (SUSMP Table 4-6) 0.04
Minimum IMP Area 235
f i'--^'^^ Proposed IMP Area'(WaterQuality treV Only)''
Bioretention Configuration KATCHALL
Total Area of DMA 9897
Tabulation of Areas Draining to Flow Through Planter DMA-7
Surface Type Area (ft') Runoff
Factor
Area x Runoff
Factor
Roofs 11595 1.0 11595
Concrete/Asphalt 1.0 0
Grouted unit Pavers 1.0 0
Solid Unit Pavers 7715 0.2 1543
Pervious concrete 1735 0.1 174
Porous Asphalt 0.1 0
Crushed Aggregate 0.1 0
Turfblock 0.1 0
Amended, Mulched soil 0.1 0
Landscape Areas 2007 0.1 201
Subtotal 13512
IMP Sizing Factor (SUSMP Table 4-6) 0.04
Minimum IMP Area 540
iiK- V^j PropbsedlMP Area (Water Qiiafity treatment Only) • r .540
Bioretention Configuration BMPSPEC*
Total Area of DMA 23052
* See Permeable Paver Details in Appendix C
16
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Preliminary SWMP
Tabulation of Areas Draining to Flow Through Planter DMA-8
Surface Type Area (ft') Runoff
Factor
Area x Runoff
Factor
Roofs 2832 1.0 2832
Concrete/Asphalt 1843 1.0 1843
Grouted unit Pavers 1.0 0
Solid Unit Pavers 5651 0.2 1130
Pervious concrete 0.1 0
Porous Asphalt 0.1 0
Crushed Aggregate 0.1 0
Turfblock 0.1 0
Amended, Mulched soil 0.1 0
Landscape Areas 5069 0.1 507
Subtotal 6312
IMP Sizing Factor (SUSMP Table 4-6) 0.04
Minimum IMP Area 252
Prd^TMPAr^(WaterQ;ialiWfiS
Bioretention Configuration BMP
Total Area of DMA 15395
Tabulation of Areas Draining to a Bioretention IMP DMA-9
Surface Type Runoff Area x Runoff Surface Type Area (ft') Factor Factor
Roofs 0 1.0 0
Concrete/Asphalt 728 1,0 728
Grouted unit Pavers 1.0 0
Solid Unit Pavers 0,2 0
Pervious concrete 0.1 0
Porous Asphalt 0.1 0
Crushed Aggregate 0.1 0
Turfblock 0.1 0
Amended, Mulched soil 0.1 0
Landscape Areas 1694 0.1 169
Subtotal 897
IMP Sizing Factor (SUSMP Table 4-6) 0.04
Minimum IMP Area 36
r Projposed IMP Area (Water Quality Treatment Only) 50
Bioretention Configuration BASIN
Total Area of DMA 2422
17
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6.2 Relative Effectiveness of Project Treatment Facilities
Hies and IMFSflilHi
Pollutants Grouped by Method of Transport
Treatment Facility/IMP Coarse
Sediment
and Trash
Pollutants
Associated with
Fine Particles
During
Transport
Pollutants
that tend to
be Dissolved
Following
Treatment
IE Bioretention IMP High High Medium
^ Flow Through Planter IMP High High Medium
• Infiltration IMP High High High
n Conventional Vegetated Swale High Medium Low
• Extended (Dry) Detention Basins High High Low
• Media (Sand) Filter High High Low
• Wet Pond High High Medium
O Constructed Wetland High High Medium
M Proprietary Vault/Tree Well High Medium Low
O Proprietary Inlet Filter High Low Low
18
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Preliminary SWMP
SECTION 7: BMP MAINTENANCE PROVISIONS
7.1 Maintenance Responsibility
On-site BMPs, and storm drain related facilities are assumed to be private, and therefore
would be maintained by the Homeowners Association or Property Manager. This
includes:
• Landscape Maintenance
• BMP Maintenance
• Common Area Litter Pickup
• Storm Drain/Catch Basin Maintenance
7.2 BMP Maintenance Matrix
Routine Maintenance Activities for Bioretention Areas
No. Maintenance Task Frequency of Task
1 Remove obstructions, debris and trash from bioretention area and
dispose of properly.
Monthly, or as needed
after storm events
2 Inspect bioretention area to ensure that it drains between storms and
within five days after rainfall.
Monthly, or as needed
after storm events
3 Inspect inlets for channels, soil exposure or other evidence of erosion.
Clear obstructions and remove sediment.
Monthly, or as needed
after storm events
4 Remove and replace all dead and diseased vegetation. Twice a year
5 Maintain vegetation and the irrigation system. Prune and weed to keep
bioretention area neat and orderly in appearance.
Before wet season
begins, or as needed
Routine Maintenance Activities for Flow-Through Planters
No. Maintenance Task Frequency of Task
1 Evaluate health of trees and groundcover. Remove and replace all
dead and diseased vegetation. Treat vegetation using preventative
and low-toxic methods.
Twice a year
2 Maintain vegetation and the irrigation system. Prune and weed to keep
flow-through planter neat and orderly in appearance.
As needed
3 Check that mulch is at appropriate depth (3 inches per soil
specifications) and replenish as necessary.
Monthly
4 Check that soil is at appropriate depth. Till or replace soil as
necessary to maintain a minimum of 6 inches between top of mulch
and overflow weir.
Before wet season and
as necessary
5 Remove accumulated sediment, litter and debris from flow-through
planter and dispose of properly. Confirm that no clogging will occur
and that the box will drain within three to four hours.
Before wet season and
as necessary
6 Inspect flow-through planter to ensure that there are no clogs. Test
with garden hose to confirm that the planter will drain within three to
four hours.
Monthly during the wet
season, and as needed
after storm events
19
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Preliminary SWMP
Routine Maintenance Activities for Bioretention Areas
7 Inspect downspouts from rooftops and sheet flow from paved areas to
ensure flow to planter box is unimpeded. Remove debris and repair
damaged pipes. Check splash blocks or rocks and repair, replace and
replenish as necessary.
Monthly during the wet
season, and as needed
after storm events
8 Inspect overflow pipe to ensure that it will safely convey excess flows
to storm drain. Repair or replace any damaged or disconnected
piping.
Before the wet season,
and as necessary
9 Inspect flow-through planter to ensure that box is structurally sound
(no cracks or leaks). Repair as necessary.
Annually
10 Inspect flow-through planter using the attached inspection checklist Monthly, or after large
storm events, and after
removal of accumulated
debris or material
Routine Maintenance Activities for Tree Well Filters (Katchall)
No. Maintenance Task Frequency of Task
1 Evaluate health oftrees and groundcover. Remove and replace all
dead and diseased vegetation. Treat vegetation using preventative
and low-toxic methods.
Twice a year
2 Maintain vegetation and the irrigation system. Prune and weed to keep
tree well filter neat and orderly in appearance.
As needed
3 Check that planting mix is at appropriate depth and replenish as
necessary.
Before wet season and
as necessary
4 Check that mulch is at appropriate depth (3 inches per soil
specifications) and replenish as necessary.
Monthly
5 Remove sediment, litter and debris from tree well filter. Confirm that
no clogging will occur and that the filter will drain per the design
specifications. Dispose of sediment, litter and debris properly.
Before wet season and
as necessary
6 Inspect Tree Well Filter to ensure that it drains between storms and
within five days after rainfall.
Periodically or as needed
after storm events
7 Inspect overfiow pipe to ensure that it will safely convey excess flows
to storm drain. Repair or replace any damaged or disconnected
piping.
As necessary
8 Inspect tree well filter using the attached inspection checklist. Monthly, or after large
storm events, and after
removal of accumulated
debris or material
20
V
STATE STREET
(PUBL IC "STRErr")"
•BMP #9 LEGEND
LANDSCAPE AREA
BIORETENTION AREA
FLOW THROUGH PLANTERS
m KATCHALL
I I PERMEABLE PAVERS
_SD—SD- PROPOSED STORM DRAIN
DMA BOUNDARIES
DIRECTION OF FLOW
EXHIBIT 1
STATE STREET TOWNHOMES
BMP EXHIBIT
SCALE: 1"=40' CQNSULTINB
A ^^^^Hcompany January 31, 2014
STATE STREET
EXHIBIT 2
STATE STREET TOWNHOMES
EXISTING DRAINAGE
E
OO
< a: Q
o z F
SCALE: r=40' • ONSULTI NB
November 13, 2013
APPENDIX "A"
Stornn Water Standards Questionnaire (E-34)
STORM WATER Development Services
Land Development Engineering STANDARDS Development Services
Land Development Engineering
CITY OF QUESTIONNAIRE
E-34
1635 Faraday Avenue
760-602-2750
CARLSBAD
QUESTIONNAIRE
E-34 www,carlsbadca.gov
To address post-development pollutants that may be generated from development projects, the City requires that new development and
significant redevelopment priority projects incorporate Permanent Storm Water Best Management Practices (BMP's) into the project
design per the City's Standard Urban Stormwater Management Plan (SUSMP). To view the SUSMP, refer to the Engineering Standards
(Volume 4, Chapter 2) at www.carlsbadca.qov/standards.
Initially this questionnaire must be completed by the applicant in advance of submitting for a development application (subdivision,
discrefionary permits and/or construction permits). The results of the questionnaire determine the level of storm water standards that
must be applied to a proposed development or redevelopment project. Depending on the outcome, your project will either be subject to
'Standard Stormwater Requirements' or be subject to additional criteria called 'Priority Development Project Requirements'. Many
aspects of project site design are dependent upon the storm water standards applied to a project.
Your responses to the questionnaire represent an initial assessment of the proposed project condifions and impacts. City staff has
responsibility for making the final assessment after submission of the development applicafion. If staff detennines that the quesfionnaire
was incorrectly filled out and is subject to more stringent stonn water standards than inifially 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 quesfion or need help in detennining how to respond to one or more of the quesfions, 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 quesfionnaire is required when multiple development applicafions forthe same project are submitted concurrenfiy.
In addifion to this quesfionnaire, you must also complete, sign and submit a Project Threat Assessment Form with construcfion permits
for the project.
Please 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.
^ -TO BE COMPLETED FOR Al
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 permeable pavements or surfaces in
accordance with USEPA Green Streets guidance?
X
2. Is your project LIMITED TO retrofitting or redeveloping exisfing 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 of the 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.
If you answered "no" to both quesfions, then go to Step 2.
E-34 Page 1 of 3 Effective 6/27/13
STORM WATER Development Services
Land Development Engineering STANDARDS Development Services
Land Development Engineering
^ CITY OF QUESTIONNAIRE
E-34
1635 Faraday Avenue
760-602-2750
CARLSBAD
QUESTIONNAIRE
E-34 www.carlsbadca.gov
Wm ^1 To determine if your project is a priority development project, please answer the following quesfions: YES NO
1. Is your project a new development that creates 10,000 square feet or more of impervious surfaces collecfively
over the entire project site? This includes commercial, industrial, residential, mixed-use, and public
development projects on public orpnvate land.
2. Is your project creafing or replacing 5,000 square feet or more of impervious surface collectively over the enfire
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
collecfively 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.
4. is your project a new or redevelopment project that creates 5,000 square feet or more of impervious surface
collectively over the enfire 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
5. Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious surface
collecfively over the entire project site and supports a parking lot. A parking lot is a land area or facility for the
temporary pari<ing or storage of motor vehicles used personally for business or for commerce.
6. Is your project a new or redevelopment project that creates 5,000 square feet or more of impervious surface
collecfively over the enfire 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.
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 enfire site, and discharges directly to an Environmentally Sensifive
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).*
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 C/ass/ffcaf/on (SIC) codes: 5013,
5014, 5541, 7532-7534, or 7536-7539.
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.
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?
Ills 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%?
If you answered "yes" to one or more of the above questions, you ARE a priority development project and are therefore subject to
implemenfing structural Best Management Practices (BMP's) in addifion to implemenfing 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
applicafion(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 quesfions, you ARE NOT a priority development project and are therefore subject to
implemenfing only Standard Storm Water Requirements such as source control and low impact development BMP's required for all
development projects. A Stonn Water Management Plan (SWMP) is not required with your application(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
^ CITY
CARLSBAD
O F
STORM WATER
STANDARDS
QUESTIONNAIRE
E-34
Development Services
Land Development Engineering
1635 FaradayAvenue
760-602-2750
www.carlsbadca.gov
•V-.f: TO BE COM' OPMENT PROJECTS IHAT ARE PRIORTTY DE
Complete the quesfions 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 ofthe previously exisfing development? X
Ifyou answered "yes," the structural BMP's required for Priority Development Projects apply only to the creafion or replacement of
impervious surface and not the enfire development Go to step 4, check the "my project meets PDP requirements" box and
complete applicant Information.
If you answered "no," the structural BMP's required for Priority Development Projects apply to the enfire development. Go to step 4,
check the "my project meets PDP requirements" box and complete applicant information.
APPROPRIATE S>i
E) My project meets PRIORITY DEVELOPMENT PROJECT (PDP) requirements and must comply with addifional stonnwater
criteria per the SUSMP and I understand I must prepare a Storm Water Management Plan for submittal at fime of applicafion.
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 ofthese requirements, I will incorporate low impact development strategies throughout my project.
Applicant Informafion and Signature Box
Intracorp Companies
Address: 4041 MacArthur Blvd., Suite 250 Accessor's Parcel Number(s): 203-054-19,20,21,22,155-200-07
Applicant Name:
Ken Benson
Applicant Title:
VP of Project Management
Applicant Signature: Date:
This Box for City Use Only
City Concurrence: YES NO
By:
Date:
Project ID:
* Environmentally Sensifive Areas include but are not limited to all Clean Water Act Secfion 303(d) impaired water bodies; areas
designated as Areas of Special Biological Significance by the State Water Resources Control Board (Water Quality Control Plan for the
San Diego Basin (1994) and amendments); water bodies designated with the RARE beneficial use by the State Water Resources
Control Board (Water Quality Control Plan for the San Diego Basin (1994) and amendments); areas designated as preserves or their
quivalent under the Multi Species Conservafion Program within the Cifies and County of San Diego; and any other equivalent
environmentally sensifive areas which have been idenfified by the Copennittees.
E-34 Page 3 of 3 Effective 6/27/13
APPENDIX "B"
BMP Fact Sheets
SECTION 4: LID DESIGN GUIDE
Bioretention Facilities
I pOTfarahid I
. UwsEnglbcflDrtodelennne minimuin craa
Bioretention facility configuied for treatment-only requirements. Bioretention facilities
can rectangular, linear, or nearly any shape.
Bioretention detains runoff in a surface reservoir, filters it through
plant roots and a biologically active soil mix, and then infiltrates it
into the ground. Where native soils are less permeable, an
underdrain conveys treated runoff to storm drain or surface
drainage.
Bioretention facilities can be configured in nearly any shape. When
configured as linear swales, they can convey high flows while
percolating and treating lower flows.
Bioretention facilities can be configured as in-ground or above-
ground planter boxes, with the bottom open to allow infiltration
to native soils underneath. If infiltration cannot be allowed, use
the sizing factors and criteria for the Flow-Through Planter.
• CRITERIA
For development projects subject only to runoff treatment
requirements, the following criteria apply:
Best Uses
• Commercial areas
• Residential
subdivisions
• Industrial
developments
• Roadways
• Parking lots
• Fit in setbacks,
medians, and other
landscaped areas
Advantages
• Can be any shape
• Low maintenance
• Can be landscaped
Limitations
• Require 4% of
tributary impervious
square footage
• T3^ically requires 3-4
feet of head
• Irrigation typically
required
Parameter
Soil mix depth
Soil mix minimum percolation rate
Soil mix surface area
Criterion
18 inches minimum
5 inches per hour minimum sustained
(10 inches per hour initial rate
recommended)
0.04 times tributary impervious area (or
equivalent)
85 City of Carlsbad SUSMP— January 14, 2011
SECTION 4: LID DESIGN GUIDE
Parameter
Surface reservoir depth
Underdrain
Criterion
6 inches minimum; may be sloped to 4
inches where adjoining walkways.
Required in Group "C" and "D" soils.
Perforated pipe embedded in gravel
("Class 2 permeable" recommended),
connected to storm drain or other
accepted discharge point.
• DETAILS
Plan. On the surface, a bioretention facility should be one level, shallow basin—or a series of
basins. As runoff enters each basin, it should flood and fiU throughout before runoff overflows
to the outiet or to the next downstream basin. This will help prevent movement of surface
mulch and soil mix.
Use check dams for linear bioretention facilities
(swales) on a slope.
In a linear swale, check dams should be placed so that the lip of each dam is at least as high as
the toe of the next upstream dam, A similar principle applies to bioretention facilities built as
terraced roadway shoulders.
Inlets. Paved areas draining to the facility should be graded, and inlets should be placed, so that
runoff remains as sheet flow or as dispersed as possible. Curb cuts should be wide (12" is
recommended) to avoid clogging with leaves or debris. AUow for a minimum reveal of 4"-6"
between the inlet and soU mix elevations to ensure turf or mulch buildup does not block the
inlet. In addition, place an apron of stone or concrete, a foot square or larger, inside each inlet to
prevent vegetation from growing up and blocking the inlet.
86 City of Carlsbad SUSMP— January 14, 2011
SECTION 4: LID DESIGN GUIDE
Recommended design details for bioretention facility inlets (see text).
Where runoff is coUected in pipes or gutters and conveyed to the faciUty, protect the landscaping
from high-velocity flows with energy-dissipating rocks. In larger instaUations, provide cobble-
Uned channels to better distribute flows throughout the faciUty.
Upturned pipe outiets can be used to dissipate energy when runoff is piped from roofs and
upgradient paved areas.
Soil mix. The required soil mix is similar to a loamy sand. It must maintain a minimum
percolation rate of 5" per hour throughout the Hfe of the faciUty, and it must be suitable for
maintaining plant Ufe. TypicaUy, on-site soUs wUl not be suitable due to clay content.
Storage and drainage layer. "Class 2 permeable," Caltrans specification 68-1.025, is
recommended. Open-graded crushed rock, washed, may be used, but requires 4"-6" washed pea
gravel be substituted at the top of the crushed rock gravel layers. Do not use filter fabric to
separate the soU mix from the gravel drainage layer or the gravel drainage layer from the native
soU.
87 City of Carlsbad SUSMP— January 14, 2011
SECTION 4: LID DESIGN GUIDE
Underdrains. No underdrain is required where native soUs beneath the facility are Hydrologic
SoU Group A or B. For treatment-only faciUties where native soUs are Group C or D, a
perforated pipe must be bedded in the gravel layer and must terminate at a storm drain or other
approved discharge point.
Outlets. In treatment-only faciUties, oudets must be set high enough to ensure the surface
reservoir fiUs and the entire surface area of soU mix is flooded before the outiet elevation is
reached. In swales, this can be achieved with appropriately placed check dams.
The oudet should be designed to exclude floating mulch and debris.
Vaults, utility boxes and light standards. It is best to locate utiUties outside the bioretention
facUity—^in adjacent walkways or in a separate area set aside for this purpose. If utility structures
are to be placed within the faciUty, the locations should be anticipated and adjustments made to
ensure the minimum bioretention surface area and volumes are achieved. Leaving the final
locations to each individual utiUty can produce a haphazard, unaesthetic appearance and make
the bioretention facility more difficult to maintain.
Emergency overflow. The site grading (construction) plan shaU include detaUs that demonstrate
the bioretention basin can handle larger (up to 1 OO-year) storm events and address potential
clogging of the overflow and route emergency overflows safely.
Trees. Bioretention areas can accommodate smaU or large trees. There is no need to subtract the
area taken up by roots from the effective area of the facility. Extensive tree roots maintain soU
permeabiUty and help retain runoff. Normal maintenance of a bioretention facUity should not
affect tree Ufespan.
The bioretention faciUty can be integrated with a tree pit of the required depth and fUled with
structural soU. If a root barrier is used, it can be located to aUow tree roots to spread throughout
the bioretention facility whUe protecting adjacent pavement. Locations and planting elevations
should be selected to avoid blocking the faciUty's inlets and outiets.
ROOT BARRIER
3^- STRUCTURAL
y SOIL
Bioretention faciJity configured as a tree weL
The root barrier is optional
88 City of Carlsbad SUSMP— January 14, 2011
SECTION 4: LID DESIGN GUIDE
• APPLICATIONS
Multi-purpose landscaped areas. Bioretention faciUties are easUy adapted to serve multiple
purposes. The loamy sand soU mix wiU support turf or a plant palette suitable to the location and
a weU-drained soU.
Example landscape treatments:
• Lawn with sloped transition to adjacent landscaping.
• Swale in setback area
• Swale in parking median
• Lawn with hardscaped edge treatment
• Decorative garden with formal or informal plantings
• Traffic island with low-maintenance landscaping
• Raised planter with seating
• Bioretention on a terraced slope
Bioretention fadlit)' configured as a recessed decorati^'e
lawn with hardscaped edge. Bioretention facility configured and planted as a lawn/ play area.
89 City of Carlsbad SUSMP— January 14, 2011
SECTION 4: LID DESIGN GUIDE
Residential subdivisions. Some subdivisions are designed to drain roofs and driveways to the
streets (in the conventional manner) and then drain the streets to bioretention areas, with one
bioretention area for each 1 to 6 lots, depending on subdivision layout and topography.
Bioretention areas may be placed on separate, jointiy-owned parcel(s).
Bioretention facility receix-ing drainage
from indi\idual lots and the street in
a residential subdivision.
Sloped sites. Bioretention facilities must be constructed as a basin, or series of basins, with the
circumference of each basin set level. It may be necessary to add curbs or low retaining waUs.
RUNOFF TO PiANTtD «»•
nwHi
CnrCDFUM OUTLET-
Bioretention facilit}' configured as a parking mediaa
Note use of tx)lJards in place of curbs, eliminating the need for curb cuts.
90 City of Carlsbad SUSMP— January 14, 2011
SECTION 4: LID DESIGN GUIDE
Design Checklist for Bioretention
• Volume or depth of surface reservoir meets or exceeds rtUnimum.
• 18" depth "loamy sand" soil mix with minimum long-term percolation rate of 5"/hour.
• Area of soU mix meets or exceeds minimum.
• Perforated pipe underdrain bedded in "Class 2 perm" with connection and sufficient head to
storm drain or discharge point (except in "A" or "B" soUs).
n No fUter fabric.
• Underdrain has a clean-out port consisting of a vertical, rigid, non-perforated PVC pipe,
with a minimum diameter of 6 inches and a watertight cap.
• Location and footprint of facility are shown on site plan and landscaping plan.
• Bioretention area is designed as a basin (level edges) or a series of basins, and grading plan is
consistent with these elevations. If facility is designed as a swale, check dams are set so the
Up of each dam is at least as high as the toe of the next upstream dam.
• Inlets are 12" wide, have 4"-6" reveal and an apron or other provision to prevent blockage
when vegetation grows in, and energy dissipation as needed.
• Overflow connected to a downstream storm drain or approved discharge point.
• Emergency spiUage wiU be safely conveyed overland.
• Plantings are suitable to the climate and a weU-drained soU.
• Irrigation system with connection to water supply.
• Vaults, UtiUty boxes, and Ught standards are located outside the minimum soU mix surface
area.
• When excavating, avoid smearing of the soUs on bottom and side slopes. Minimize
compaction of native soUs and "rip" soUs if clayey and/or compacted. Protect the area from
construction site runoff
91 City of Carlsbad SUSMP— January 14, 2011
SECTION 4: LID DESIGN GUIDE
FOREBAY/CLEWOUr
HEAMfAU.
EMERGENCY SPiaWAY
TOP OF BASIN
PLAN VIEW
NOT TO SCALE
TOP OF BASIN
EHERGENCY
SPILLWAY-
FOREBAY/CLEANOUT
^OUTFLOW "'ifel
CLASS 2 PERM.
PERFORAIED PIPE
(UNDERDRAIN]
V2 STORAGE ^18" SPECIFIED
(NOTE 2) PLANTING MIX
e A>, SECTION
NOT TO SOU
NOTE
SURFACE AREA LIMfT DETERMINED BY EXTENT OF SPECIFIED PLANTING MIX, WHICH
IS GOVERNED BY THE OUTLH SPILL ELEVATION. FOR REOUIRED SURFACE AREA REFER TO THE FACTORS AMD EQUATIONS IN THE STORMWATER
Ci GUIDEBOOK.
Vi STORAGE ACCOMPLISHED WITH INFILTRATION ARCHES, PERFORATED PIPES, CLASS 2 PERM OR OTHER AT THE DESIGNERS DISCREnON.
Bioretention Facility
92 City of Carlsbad SUSMP— January 14, 2011
SECTION 4: LID DESIGN GUIDE
FLANGE ll ORinCE
PLATE CONNECTION
(SEE NOTE 1) CLOSED MESH ORATE
(GEN. NOTES 4 THRU 7)
PLAN
CATCH BASIN
SPECIRED SOIL MIX \ 2,
-CLOSED MESH GRATE
(GEN. NOTES 4 THRU 7)
ORIRCE PLATE: MIN SOUARE
DIMENSIONS 1.0 FT GREATER THAN PIPE DIA HOT-DIP
GALVANIZED PLATE AFTER
HOLES HAVE BEEN DRILLED r-UIN 6- (TYP)
• (TYP)
NOTE
ORinCE PUTE & FLANGE
CONNECTION TO CONCRETE SHALL BE FITTED WITH
30 DUROMETER NEOPRENE RING.
iRinCE DIAMETER (DW)
SIZED PER DESIGN CRIIERUk
|T)IA HOLE (TYP)
FLOW CXJNTROL ORIFICE PLATE
Bioretention Facility Outlet Detail - A
93 City of Carlsbad SUSMP— January 14, 2011
SECTION 4: LID DESIGN GUIDE
'low-through Plariter
Portland 2(J(V4 Stonnwater Manual
Best Uses
• Management of roof
runoff
• Next to buUcUngs
• Dense urban areas
• Where infiltration is
not desired
Advantages
• Can be used next to
structures
• Versatile
• Can be any shape
• Low maintenance
Flow-through planters treat and detain runoff without aUowing seepage
into the underlying soU. They can be used next to buUdings and on slopes
where stabiUty might be affected by adding soU moisture.
Flow-through planters typicaUy receive runoff via downspouts leading
from the roofs of adjacent buUdings. However, they can also be set in-
ground and receive sheet flow from adjacent paved areas.
PoUutants are removed as runoff passes through the soU layer and is
coUected in an underlying layer of gravel or drain rock. A perforated-pipe
underdrain is t)fpicaUy connected to a storm drain or other discharge
point. An overflow inlet conveys flows which exceed the capacity of the
planter.
CRITERIA
Treatment only. For development projects subject only to runoff treatment requirements, the
foUowing criteria apply:
Limitations
• Can be used for
flow-control only on
sites with "C" and
"D" soUs
• Requires underdrain
• Requires 3-4 feet of
head
Parameter
Soil mix depth
Soil mix minimum percolation
rate
Criterion
18 inches minimum
5 inches per hour minimum sustained
(10 inches per hour initial rate
recommended)
94 City of Carlsbad SUSMP— January 14, 2011
SECTION 4: LID DESIGN GUIDE
Parameter Criterion
Soil mix surface area 0.04 times tributary impervious area (or
equivalent)
Surface reservoir depth 6" minimum; may be sloped to 4"
where adjoining walkways.
Underdrain TypicaUy used. Perforated pipe
embedded in gravel ("Class 2
permeable" recommended), connected
to storm drain or other accepted
discharge point.
• DETAILS
Configuration. The planter must be level. To avoid standing water in the subsurface layer, set
the perforated pipe underdrain and orifice as nearly flush with the planter bottom as possible.
inlets. Protect plantings from high-velocity flows by adding rocks or other energy-dissipating
structures at downspouts and other inlets.
Soil mix. The required soU mix is simUar to a loamy sand. It must maintain a mirumum
percolation rate of 5" per hour throughout the Ufe of the faciUty, and it must be suitable for
maintaining plant Ufe. TypicaUy, on-site soUs wUl not be suitable due to clay content.
Gravel storage and drainage layer. "Class 2 permeable," Caltrans specification 68-1.025, is
recommended. Open-graded crushed rock, washed, may be used, but requires 4"-6" of washed
pea gravel be substituted at the top of the crushed rock layer. Do not use filter fabric to
separate the soU mix from the gravel drainage layer.
Emergency overflow. The planter design and instaUation should anticipate extreme events and
potential clogging of the overflow and route emergency overflows safely.
• APPLICATIONS
Adjacent to buildings. Flow-through planters may be located adjacent to buUdings, where the
planter vegetation can soften the visual effect of the buUding waU. A setback with a raised
planter box may be appropriate even in some neo-traditional pedestrian-oriented urban
streetscapes.
At plaza level. Flow-through planters have been successfuUy incorporated into podium-style
developments, with the planters placed on the plaza level and receiving runoff from the tower
roofs above. Runoff from the plaza level is typicaUy managed separately by additional flow-
through planters or bioretention faciUties located at street level.
Steep slopes. Flow-through planters provide a means to detain and treat mnoff on slopes that
cannot accept infiltration from a bioretention faciUty. The planter can be buUt into the slope
simUar to a retaining waU. The design should consider the need to access the planter for periodic
95 City of Carlsbad SUSMP— January 14, 2011
SECTION 4: LID DESIGN GUIDE
maintenance. Flows from the planter underdrain and overflow must be directed in accordance
with local requirements. It is sometimes possible to disperse these flows to the downgradient
hillside.
Flow-through planter on the plaza level of a podium-style development
Flow-through planter built into a hillside. Flows from the underdrain and
overflow must be directed in accoidance with liKal requirements.
96 City of Carlsbad SUSMP— January 14, 2011
SECTION 4: LID DESIGN GUIDE
Design Checklist for Flow-through Planter
• Reservoir depth is 4-6" minimum.
• 18" depth "loamy sand" soU mix with minimum long-term infiltration rate of 5"/hour.
• Area of soU mix meets or exceeds minimum.
• "Class 2 perm" drainage layer,
n No fdter fabric.
• Perforated pipe underdrain with outiet located flush or nearly flush with planter bottom.
Connection with sufficient head to storm drain or discharge point.
• Underdrain has a clean-out port consisting of a vertical, rigid, non-perforated PVC pipe,
with a minimum cUameter of 6 inches and a watertight cap.
• Overflow connected to a downstream storm drain or approved discharge point.
• Location and footprint of facility are shown on site plan and landscaping plan.
• Planter is set level,
• Emergency spillage wUl be safely conveyed overland.
• Plantings are suitable to the climate and a weU-drained soU.
• Irrigation system with connection to water supply.
97 City of Carlsbad SUSMP— January 14, 2011
SECTION 4: LID DESIGN GUIDE
EMERGENCY 0VERFU3W
GRATE
(SEE FLOW-THROUGH
PLANTER OUTLET DEIAl)
ENERGY DISSIPATION
DOWNSPOUT/INLET
DISCHARGE TO AN
APPROVED LOCATION
CONCRETE OR OTHER
STRUCTURAL PLANTER WALL WITH Y«ATERPROOFING
PLAN
LOCKED, REMOVABLE
CLOSE-MESH GRATE, SLOPED INSTALLATION
PLANTER OUTLET
(SEE FLOW-THROUGH PLANTEP
OUTLET DETAIL)
DISCHARGE
TO AN
APPROVED LOCATION
ONE-WAY
CONNECTIONS
NOTES:
PERFORATED PIPE-
(UNDERCRAIN)
MIN SL0PE»a5X
SECTION
ORinCE DRILLED INTO VAULT WALL
FORM A 1.5' GROOVE IN
CONCRETE AND PROVIDE A CONTINUOUS WATERTIGKT
CONNECTION, USING AN
APPROVEO SEALANT
FLOW-THROUGH PLANTER SHAU. BE SIZED TO MEET
CCCWP CRITERIA FOR TREATMENT AND/OR aOW CONIROL.
MINIMUM SURFACE AREA OF PLANTER IS 4X OF TWBUTARY IMPERVIOUS AREA
FOR TREATMENT ONLY DESIGN. FDR aOW CONIROL AND TREATMENT,
REFER TO CCCWP SIZING TOOL CRITERIA
SHAPE OF PLANTER CAN VARY TO MEET PROJECT
DESIGN REQUIREMENTS AND LOCATION.
CLASS 2 PERMEABLE MATERIAL
DOWNSPOUTS/INLET PIPES REQUIRE ENERGY DISSIfvmON.
USE COUNIY APPROVED ADDITIVE MIXTURE FOR WATERPROOnNG CONCRETE.
PLANTINGS: SEE CCCWP RECOMMENDED PLANT UST AND GUIDELINES.
PLANTER DESIGN MAY REOUIRE STRUCTURAL ENGINEERING DESIGN.
AREA = W « L (ABOVE). EXCLUDES AREA OF VAULT
Flow-Through Planter Detail
98 City of Carisbad SUSMP— January 14, 2011
SECTION 4: LID DESIGN GUIDE
STEEL VAULT FRAME
(NOTE 1
ORCULAR ORIFICE DRILLED
INTO GALVANIZED SIEEL VAULT
'LANIER
BOX WALL
CLOSED MESH GRATE
(GEN. NOTES 2 THRU 5)
VAULT-PLANTER BOX
CONNECTION PLAN
HOT-DIP GALVANIZE ENTIRE FRAME
ASSEMBLY AFTER FABRICATION AND
AFTER HOLES HAVE BEEN DRILLED.
2. FOR WATERHGHT'CONNECTION, INSTALL
J" TD 1' THICK X 2" WIDE CONTINUOUS
30 DUROMETER NEOPRENE CASKET, AU
AROUND VAULT FTWNE.
LOCKED, REMOVABLE
CLOSE-MESH GRATE.
SLOPED INSTALUTION
DISCHARGE
. TO AN
I=C> APPROVED
' LOCATION
ORIRCE DRILLED
INTO VAULT WALL
SECTION
N.T.S.
GENERAL OUTLET DETAIL NOTES:
1. OUTFALL PIPE SHALL BE SIZED TO CONVEY DESIGN STORM
PER CCCWP DESIGN CRITERIA
2. CRATE SHAa BE MOUNTED USING STAINLESS STEEL HARDWARE AND PROVIOED WITH HINGED AND LOCKABLE
OR BOLTABU ACCESS PANELS.
3. GRATE SHALL BE STAINLESS STEEL. ALUMINUM OR STEEL STEEL GRATES SHALL BE HOT OIP GALVANIZED
AND MAY BE HOT POWDER PAINTED AFTER GALVANIZING.
4. GRATE SHALL BE DESIGNED SUCH THAT THE DIAGONAL DIMENSION OF EACH OPENING IS SMALLER THAN THE
DIAMETER OF THE OUTLET PIPE.
5. STRUCTURAL DESIGN OF GRATE SHALL BE BASED ON FULL HYOROSTATK; HEAD WTIH ZERO HEAD DOWNSTREAM
OF ORATE.
Flow-Through Planter Outlet Detail
99 City of Carisbad SUSMP— January 14, 2011
APPENDIX "C"
Proprietary BMP Manufacturer Infornnation
SECTION 4
PURESTREAM ™
Without a doubt, the most popular and most often specified Biofiltration device we manufacture.
Drawing on the dismal failures of some of the stand-alone BioRetention "tree box systems", Katchall
designed a single-vault system that includes ALL of the following features:
1. A properly designed BloFiltration System,
2. Pre-Entry trash / debris screen (coptures all materials > 3/8-Inch),
3. Filtered high-flow bypass chamber, {eliminates the need for secondary inlet structures),
4. Volume capture and treatrnent has been dramatically increased over competing products,
5. Draw-down times have been substanuallv decreased over competing products, (<2-hours).
Katchall's PURESTREAM is the ONLY device that incorporates a hieh-flow bypass within the same
structure as the filtration media, eliminating the need fora secondary curb inlet next to each device.
(All other competing products [tree boxes] require a 2ndry Inlet to handle high-flow storm events)
PURESTREAM BioFiltration Chambers are available in a variety of sizes, from our smallest 400 Series
to our largest 2000 Series; units are configured so as to drain in virtually any direction. I.e. rear, sides,
front.
Every one of our systems is designed to capture and filter sheet flows up to a minimum of a 2S-year
storm event, no other company - no other product is designed to treat discharges larger than "first-
flush". Independent 3"* party testing has shown that a Model 6-4-4 captures and treats
discharges @ 281.8-lnches per hour! NO OTHER PRODUCT ON THE MARKET COMES CLOSE TO THAT.
Why specific, or ask your client to pay for a product that captures and filters LESS than 10% of the
runoff from a small storm event?
90 % of the runoff generated is going straight into the secondary bypass inlet structure and is
discharging direct Into our creeks, streams, rivers, lakes and oceans, WITHOUT ANY TREATMENT
WHATSOEVER. IVasn't this just what the Clean Water Act was supposed to have prevented?
In addition to our standard "off-the-shelf models, the Katchall PURESTREAM BioFiltration Chambers
are available as custom design-build units and can include some of our most popular options such as:
"Raw Steel" Grates in a variety of design - patterns,
Powder-Coated Grates (multiple colors are available).
Custom-designed Tree / Shrub Grates {your logo, project name, street name, etc.)
Multiple Tree / Shrub Grate configurations (See Series 1200 ~ Series 2000),
Colored stamped concrete finishes.
Recessed Top Decks Including vegetation, brick pavers, etc.
A variety of Park Benches, multiple colors and finishes are available.
Benches can Include street names, logos, etc. embossed on top rails.
Katchall Filtration Systems, LLC | www.katchall.net
sum. IREE 08 SHRUB
(PLtASE mxm
KATCHAU. VOR K UST
Of COUPAHaE SPECIES)
6" ACXCSS FOR niTER REPLACEMENT
36'x36" TREE (XAIE
SIDEWALK W OTHER
ADJACENT SURFACE
INaUOES PRE-PLUMBED
DBP IRRIGATIOM SYSTEM
PIPES UAY OOTLtT SIDES OR BACK OF VAULT
TYPICAL LOCAL DEPRESSION
CURB INLET
6' CASI-BI-PUCE
REiMfO«C£0
CO{;CREre VAULT
simm mair
N.T.S.
KATCHALL
nilRATiONSYSIEMS.aC 1-886-KATGHALL
WWW.KATCHALL.NET
PURESTREAM^* BIO-FiLTRATlON
FOR LA FORESTA PROJECT
REVISia<:
A
DW6 NUM;
U FORESTA
SHEET:
1 OF 3
Katchall Filtration Systems, LLC ] www.katchall.net
Models / Sizes / Filtration Flow-Rates
(Most specified - several other sizes are available / each series)
Independent 3'^^ party testing has demonstrated (unobstructed) capture /filtration @ 181.8-inches/ hour
Series
Model
Dimensions
LxWxD
Rear Discharge
GPM
Rear Discharge
Cfs
Side Discharge
GPM
Side Discharge
Cfs
400 Series
4-4-4 4x4x4 41.9 5.6 43.9 5.8
600 Series
6-4-4 6x4x4 63.6 8.5 45.6 6.1
6-6-4 6x6x4 68.8 9.2 50.9 6.8
800 Series
8-4-4 8x4x4 83.8 11.2 49.4 6.6
8-6-4 8x6x4 91.3 12.2 92.0 12.3
1000 Series
10-4-4 10 X 4 x 4 103.9 13.9 53.1 7.1
10-6-4 10 x 6 X 4 123.4 16.5 106.2 14.2
1200 Series
12-4-4 12x4x4 124.9 16.7 56.9 7.6
12-6-4 12x6x4 148.1 19.8 114.4 15.3
1400 Series
14-4-4 14 X 4 X 4 145.9 19.5 61.3 8.2
14-6-4 14 x 6 X 4 173,5 23.2 122.7 16.4
1600 Series
16-4-4 16 X 4 X 4 166.8 22.3 65.1 8.7
16-6-4 16x6x4 197.5 26.4 130.2 17.4
1800 Series
18-4-4 18 X 4 X 4 187.8 25.1 68.8 9.2
18-6-4 18x6x4 222.9 29.8 137.6 18.4
2000 Series
20-4-4 20 X 4 X 4 208.7 27.9 72.6 9.7
20-6-4 20x6x4 247.6 33.1 145.9 19.5
Katchall Filtration Systems, LLC ] www.katchall.net
Single Grate Configuration
mfO. TREE OR SHRUB
(HXASC CWTACr
KATCHMX FOR A UST
OF COHPAlBUt 5PEGES)
ACCESS FDR WAWTENyiCE -v
OF WinWCROaAL aTFR \
StOEV/AUC OR OTHER
At)JACEK T SURFACE
naiOEB FRE-PLUUBED
OPSP RRCATlCfl S>S!EII
PIPES MAY OlflLET SDE3
OR ayiK CF VAun
IKEE CRATE
iiiiffi
TV7ICA1. LOCM. OEPIXSSIOli
CURB IHIET
8* CA31-IH-Pt«e
REmFDRCED COHCRETE VAUn
M.T.S
ADCES rai; ttAnTB<A)l[£
OF ANIIUKRtHAl FLIER
-or coixBOE'ieR
WML (StE OCTAL V)
REAR DISCHfflflt; n.TS. riTS.
4' eetiCAETt >iER
WAU. (SEC DETAL
ACCESS FOR UAnTEHANCE
or AMTWWWIfL FILIIR
KATCHALL
FILTHATtON 8YSTCMS> LLC 1-8684<ATCHALL
WWW.KATCHALLNET
PURESTREAM BIO-FILTRATION
SYSTEM 40tK«ERIES
REMSIDH:
0
rm, HUM:
PURE40D
SHEET:
1 OF 2
Katchall Filtration Systems, LLC | www.katchall.net
Dual Grate Configuration
INCLUDES Pm-PUMBB) ORP IRRICA1IQH s^ml
PPES MAY WME! SIDES
OR BACK CF VAULT
SM'U THEE OR SHftPB
(PUASE COMTACT
KAtCHALl rCR A US1
OF CdiPATiaf SPtQES)
ACCESS m mnmuKf. or AUHMCMGIH. RLTCR
SIDEWALK OR OTHER ADJftCEJJT SURFACC
3t r3t TREE GRATE
T>?ICAL LOCAL CEPRtSSWi
INLET
r C4STHH-PU1CE
COflOm VWLT
fl.T.S.
MXISS FQR MMNTDIANCC
OF AMTOCRDBIAL flLIW
4" COICBLTE WJR
WALLS (SEt DETWL "A")
mm
H.T.&
• 4' GOnCEETE ROB
WAU (SEE OeVIL
/-ACCESS njR
/ UANTtrWlCE OF AlfllMCROQM. FILRR
3DE DISCHARGC N.T.S.
KATCHALL
FimwriQN SYSTEMS. U-C 1-863-KATCHALL
WWW.KATCHALLNET
PURESTREAM™ BlO-FILTRATION
SYSTEM 1200^ER1ES
ftCVlSIOH;
0
owe HUM:
PUREI200
SHEET:
I OF 2
Katchall Filtration Systems, LLC | www.katchall.net
Triple Grate or Park Bench Configuration
SWAIL IREE OR 91RUB
(FlEWt mnfict KAimiL FOR A usr
CF CONPAIBU S'ECIES}
ACCESS rem vmjtHfitcc
DF mmavsBn HLTER
SIDDVALK OR OTHER ADJACENT SURrACC
?4*»2«' TRtC BRATE
TVaCAl LCCrt. DEPffiSaUM
WODKS PKE-PUIkflED
DBP iKRioAncrj sf/am
RPEB MAV ouriEr goes
Cfi BACK OF V-OJULr
ADcesa ruK UAmainna.
QF AHITidCROHAl FVIER
INLET
yratr xm mn.
t' CUST-ltJ-PLACe
raKFORceo
O0f(CRETE VAUn
M.T.S.
STAHD^HD LASTlUr
H.T.Si
4" DOflCRnE mn H'AILS
(SEE CETAIL 'A*)
4
- 4* COHCRETE'itR
WAU. pGE OCTAL "A")
-ACCESS FOR mHTQIMISE OF
AiiriMEROnAL RLIER
aPE HSCHflRg. N.T.5.
KATCHALL
FILTRATION SYSTEMS, tlC l-«68-KATCHALL
WWW.KATCHALLNET
PUFIESTFIEAM™ BIO-FILTTWION
SYSTEM 200(VSERIES
REViSOH:
0
om HUM:
PURE2000
SHECT:
1 OF 2
Katchall Filtration Systems, LLC 1 www.katchall.net
Cf *N«(iiCRa)/.L n.Tj; /
(«t C^i. V.')
-4-VARIES H--
»MrM6»C0'N. «l« WA.L
own 'll'E-^
ti il
ffi:cTi
m.
/ tftBi
'I
UTS.
mo mf. Pa«nv; jtt
-aicwi!. iiruMCN
*• :o\c;tn w >.u.
wiUv.ttiiwL wnmiz-t-i-iic* ntr/iFn *n:.\
N.tS.
L «!iHcnu'.m ninR «(t;s w\Efs - ms'mzoi os .'ow-s COATED. 2 PRC HIMKJ ORP ISflOfilCH itSTSi 5 PCtlUfi WBl *1. -rtJ.lf,.
1 sniirmccs tc»i(5?c:c V,WLTS Aff c».si-iii-!=uc£ 4.5iA*»ir> uat tKA-ts Avy.'.iBii IV «.\viir sinrs "a wi"tv YOLR PMJ-CTS MSTVEBC.. 5 HC«HAR W.» IS aO-iEa^ASABJt OXOMJI MvSl
MOXI
mm cm A
(FT)
0W8 OMC DWD
(IN)
TRAS« (CUfT) C<$CHARC-E
PPES (W) («ri) {CTS) aTtstD nw (iTS)
81l?A.SS I TOWJ.
i,-i-t 10 •5'-1Ii J.J 3.5
KATCHALL
FILTRATION SYSTEMS, LLC
1-866-KATCHALL
WWW.KATCHALL.NET
PURESTREAM™ BIO-FILTRATION
FOR WHOLE FOODS RICHMOND
A FURE-WR SHEET:
? 0- 6
MODIFIED PURESTREAM - NO CURB INLET
(Pipe In & Pipe Out)
Katchall Filtration Systems, LLC | www.katchall.net