HomeMy WebLinkAboutCT 2018-0002; AVIARA APARTMENTS; PRIORITY DEVELOPMENT PROJECT (PDP) STORM WATER QUALITY MANAGEMENT PLAN (SWQMP); 2022-04-29
TABLE OF CONTENTS
Certification Page
Project Vicinity Map
FORM E-34 Storm Water Standard Questionnaire
Site Information
FORM E-36 Standard Project Requirement Checklist
Summary of PDP Structural BMPs
Attachment 1: Backup for PDP Pollutant Control BMPs
Attachment 1a: DMA Exhibit
Attachment 1b: Tabular Summary of DMAs and Design Capture Volume Calculations
Attachment 1c: Harvest and Use Feasibility Screening (when applicable)
Attachment 1d: Infiltration Feasibility Analysis (when applicable)
Attachment 1e: Pollutant Control BMP Design Worksheets / Calculations
Attachment 1f: Trash Capture BMP Requirements
Attachment 2: Backup for PDP Hydromodification Control Measures
Attachment 2a: Hydromodification Management Exhibit
Attachment 2b: Management of Critical Coarse Sediment Yield Areas
Attachment 2c: Geomorphic Assessment of Receiving Channels
Attachment 2d: Flow Control Facility Design
Attachment 3: Structural BMP Maintenance Thresholds and Actions
Attachment 4: Single Sheet BMP (SSBMP) Exhibit
Attachment 5: Geotechnical Report
Appendix A: Old SWQMP Reports
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PROJECT VICINITY MAP
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SITE INFORMATION CHECKLIST
Project Summary Information
Project Name LAUREL TREE LANE STREET WIDENING
Project ID CT2018-0002 / 535-1
Project Address 1305 Aviara Parkway
Assessor's Parcel Number(s) (APN(s)) 212-040-56
Project Watershed (Hydrologic Unit) Carlsbad 904 / Encinas 904.4
Parcel Area:**Disturbed Area in Public ROW
0.465 Acres
(20,254 Square Feet)
Existing Impervious Area
(subset of Parcel Area)
0.297 Acres
(12,927 Square Feet)
Area to be disturbed by the project
(Project Area)
0.465 Acres
(20,254 Square Feet)
Project Proposed Impervious Area
(subset of Project Area)
0.265 Acres
(11,549 Square Feet)
Project Proposed Pervious Area
(subset of Project Area)
0.200 Acres
(8,705 Square Feet)
Note: Proposed Impervious Area + Proposed Pervious Area = Area to be Disturbed by the
Project.
This may be less than the Parcel Area.
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Description of Existing Site Condition and Drainage Patterns
Current Status of the Site (select all that apply):
X Existing development
Previously graded but not built out
Agricultural or other non-impervious use
Vacant, undeveloped/natural
Description / Additional Information:
Laurel Tree Lane & Aviara Parkway are improved public streets. Drainage patterns are urban.
Existing Land Cover Includes (select all that apply):
Vegetative Cover
X Non-Vegetated Pervious Areas
X Impervious Areas
Description / Additional Information:
Paved streets. Pervious area behind the sidewalk.
Underlying Soil belongs to Hydrologic Soil Group (select all that apply):
X NRCS Type A
NRCS Type B
NRCS Type C
NRCS Type D
Approximate Depth to Groundwater (GW):
GW Depth < 5 feet
5 feet < GW Depth < 10 feet
10 feet < GW Depth < 20 feet
X GW Depth > 20 feet
Existing Natural Hydrologic Features (select all that apply):
Watercourses
Seeps
Springs
Wetlands
X None
Description / Additional Information:
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Description of Existing Site Topography and Drainage [How is storm water runoff conveyed from
the site? At a minimum, this description should answer (1) whether existing drainage
conveyance is natural or urban; (2) describe existing constructed storm water conveyance
systems, if applicable; and (3) is runoff from offsite conveyed through the site? if so, describe]:
Laurel Tree Lane is partially improved, with the north (project) frontage limited to an asphalt berm
without sidewalk. Surface discharge is primarily overland from the center of the paved street to
the asphalt berm on the north side, then easterly along the berm to an asphalt spillway, which
discharges northeasterly toward the Canyon de las Encinas watercourse.
Aviara Parkway is fully improved along the length of the project frontages with full width pavement,
curb & gutter, contiguous sidewalk and a raised median. There are curb return improvements at
the Laurel Tree Lane intersection, and at the 2 driveway entries along the Aviara West frontage.
Aviara Parkway slopes south to north toward Palomar Airport Road, with surface runoff directed
from the median out to the curb & gutter to curb inlets located on either side of the street,
approximately 300 feet north of the Avaia Apartment sites (about 100’ south of Palomar Airport
Road intersection)
The Aviara East site drains northerly toward Canyon de las Encinias with the northwesterly portion
of the site intercepted by a headwall and storm drain connected to the culvert under Aviara
Parkway.
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Description of Proposed Site Development and Drainage Patterns
Project Description / Proposed Land Use and/or Activities:
Laurel Tree Lane: Pavement widening and frontage improvements (curb & gutter, sidewalk)
north side (Public Street) including a replacement curb inlet east of the Aviara East site.
Construct tree wells and a driveway entrance to the future development.
Aviara Parkway: replace median, add driveway, replace pedestrian ramp and cross gutters, add
landscaping behind sidewalk. .
List/describe proposed impervious features of the project (e.g., buildings, roadways, parking
lots, courtyards, athletic courts, other impervious features):
New paving, curb & gutter, sidewalks, and driveways.
List/describe proposed pervious features of the project (e.g., landscape areas):
Tree wells (from County Green Streets manual), landscaping in the parkway behind sidewalk,
temporary slope below tree wells.
Does the project include grading and changes to site topography?
X Yes
No
Description / Additional Information:
Grading to construct tree wells prior to adjacent project construction. Minor grading to maintain
drainage patterns.
Does the project include changes to site drainage (e.g., installation of new storm water
conveyance systems)?
X Yes
No
Description / Additional Information:
The project maintains the existing discharge locations and avoids diversion.
Laurel Tree Lane will still drain to the east and Aviara Parkway will still drain towards the north.
All of the proposed flows are tributary to Canyon de las Encinas.
New inlet will replace the asphalt spillway near the east end of Laurel Tree Lane. A subdrain
outlet will discharge to the Aviara East site.
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Identify whether any of the following features, activities, and/or pollutant source areas will be
present (select all that apply):
X On-site storm drain inlets
Interior floor drains and elevator shaft sump pumps
Interior parking garages
Need for future indoor & structural pest control
Landscape/Outdoor Pesticide Use
Pools, spas, ponds, decorative fountains, and other water features
Food service
Refuse areas
Industrial processes
Outdoor storage of equipment or materials
Vehicle and Equipment Cleaning
Vehicle/Equipment Repair and Maintenance
Fuel Dispensing Areas
Loading Docks
Fire Sprinkler Test Water
Miscellaneous Drain or Wash Water
X Plazas, sidewalks, and parking lots
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Identification of Receiving Water Pollutants of Concern
Describe path of storm water from the project site to the Pacific Ocean (or bay, lagoon, lake or
reservoir, as applicable):
Storm water travels 2 miles to the Pacific Ocean through the Canyon de las Encinas
List any 303(d) impaired water bodies within the path of storm water from the project site to the
Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable), identify the
pollutant(s)/stressor(s) causing impairment, and identify any TMDLs for the impaired water
bodies:
303(d) Impaired Water Body Pollutant(s)/Stressor(s) TMDLs
Pacific Ocean Shoreline Indicator Bacteria, total coliform Indicator Bacteria,
enterococcus, fecal coliform,
total coliform
Identification of Project Site Pollutants
Identify pollutants anticipated from the project site based on all proposed use(s) of the site (see
Table B.6-1 below):
Pollutant
Not Applicable to
the Project Site
Anticipated from the
Project Site
Also a Receiving
Water Pollutant of
Concern
Sediment
X
Nutrients
X
Heavy Metals
X
Organic Compounds
X
Trash & Debris
X
Oxygen Demanding
Substances
P
Oil & Grease
P
Bacteria & Viruses
P
Pesticides
X
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TABLE B.6-1. Anticipated and Potential Pollutants Generated by Land Use Type
Priority
Project
Categories
General Pollutant Categories
Sediment
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(1)
P(2)
P
X
Commercial
Development
>one acre
P(1)
P(1)
X
P(2)
X
P(5)
X
P(3)
P(5)
Heavy
Industry
X
X
X
X
X
X
Automotive
Repair Shops
X
X(4)(5)
X
X
Restaurants X X X X P(1)
Hillside
Development
>5,000 ft2
X
X
X
X
X
X
Parking Lots
P(1)
P(1)
X
X
P(1)
X
P(1)
Retail
Gasoline
Outlets
X
X
X
X
X
Streets,
Highways &
Freeways
X
P(1)
X
X(4)
X
P(5)
X
X
P(1)
X = anticipated
P = potential
(1) A potential pollutant if landscaping exists onsite.
(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.
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Trash Capture BMP Requirements
The project must meet the following Trash Capture BMP Requirements (see Section 4.4 of the
BMP Design Manual): 1) The trash capture BMP is sized for a one-year, one-hour storm event
or equivalent storm drain system, and 2) the trash capture BMP captures trash equal or greater
to 5mm.
Description / Discussion of Trash Capture BMPs:
Trash capture screen will be installed at the inlet replacement.
Hydromodification Management Requirements
Do hydromodification management requirements apply (see Section 1.6 of the BMP Design
Manual)?
X Yes, hydromodification management flow control structural BMPs required.
No, the project will discharge runoff directly to existing underground storm drains discharging
directly to water storage reservoirs, lakes, enclosed embayments, or the Pacific Ocean.
No, the project will discharge runoff directly to conveyance channels whose bed and bank are
concrete-lined all the way from the point of discharge to water storage reservoirs, lakes,
enclosed embayments, or the Pacific Ocean.
No, the project will discharge runoff directly to an area identified as appropriate for an
exemption by the WMAA for the watershed in which the project resides.
Description / Additional Information (to be provided if a 'No' answer has been selected above):
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Critical Coarse Sediment Yield Areas*
*This Section only required if hydromodification management requirements apply
Based on the maps provided within the WMAA, do potential critical coarse sediment yield areas
exist within the project drainage boundaries?
Yes
X No, no critical coarse sediment yield areas to be protected based on WMAA maps
If yes, have any of the optional analyses presented in Appendix H of the manual been
performed?
H.6.1 Site-Specific GLU Analysis
H.7 Downstream Systems Sensitivity to Coarse Sediment
H.7.3 Coarse Sediment Source Area Verification
No optional analyses performed, the project will avoid critical coarse sediment yield areas
identified based on WMAA maps
If optional analyses were performed, what is the final result?
No critical coarse sediment yield areas to be protected based on verification of GLUs onsite.
Critical coarse sediment yield areas exist but additional analysis has determined that
protection is not required. Documentation attached in Attachment 8 of the SWQMP.
Critical coarse sediment yield areas exist and require protection. The project will implement
management measures described in Sections H.2, H.3, and H.4 as applicable, and the areas
are identified on the SWQMP Exhibit.
Discussion / Additional Information:
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Flow Control for Post-Project Runoff*
*This Section only required if hydromodification management requirements apply
List and describe point(s) of compliance (POCs) for flow control for hydromodification
management (see Section 6.3.1). For each POC, provide a POC identification name or number
correlating to the project's HMP Exhibit and a receiving channel identification name or number
correlating to the project's HMP Exhibit.
POC-1 will be the proposed inlet near the east end of Laurel Tree Lane based upon the
combined HMP mitigation of the street tree wells.
POC-2 and POC-3 area the curb inlets on Aviara Parkway at Canyon de las Encinas, which
receive runoff from proposed Aviara Parkway improvements (driveways, curb returns, and
median work)
Has a geomorphic assessment been performed for the receiving channel(s)?
X No, the low flow threshold is 0.1Q2 (default low flow threshold)
Yes, the result is the low flow threshold is 0.1Q2
Yes, the result is the low flow threshold is 0.3Q2
Yes, the result is the low flow threshold is 0.5Q2
If a geomorphic assessment has been performed, provide title, date, and preparer:
Discussion / Additional Information: (optional)
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Other Site Requirements and Constraints
When applicable, list other site requirements or constraints that will influence storm water
management design, such as zoning requirements including setbacks and open space, or City
codes governing minimum street width, sidewalk construction, allowable pavement types, and
drainage requirements.
· Widening Laurel Tree Lane while maintaining the existing drainage patterns.
· Narrow right of way. There is only 7-feet between the face of curb and the property line.
· No underground storm drain systems to tie into
· Coordination on the proposed project north of Laurel Tree (Aviara Apartments East). We are
providing access to this proposed development off of Lauren Tree Lane and Aviara Parkway.
Optional Additional Information or Continuation of Previous Sections As Needed
This space provided for additional information or continuation of information from previous
sections as needed.
The Aviara Apartments West project will include Laurel Tree Lane widening, and the
Aviara Parkway frontage improvements. The Aviara East site will be Phase 2, developed
as an affordable housing developer, with a different Engineer of Work.
There are coordination efforts that need to occur between us and the developer of Aviara
East so they can build the future retaining wall that will provide support for our proposed
private tree wells along the frontage, outside the right of way.
The private tree wells will have 15’ trees: WILLOW PITTOSPORUM, ARROYO WILLOW.
This will be designed by the landscape architect hired by the east project developer.
They will be privately maintained by the Aviara East development.
STANDARD PROJECT
REQUIREMENT
CHECKLIST
E-36
Development Services
Land Development Engineering
1635 Faraday Avenue
(760) 602-2750
www.carlsbadca.gov
Project Information
Project Name: LAUREL TREE LANE
Plan ID: Permit No.
DWG No.
Baseline BMPs for Existing and Proposed Site Features
Complete the Table 1 - Site Design Requirement to document existing and proposed site features and the BMPs to be
implemented for them. All BMPs must be implemented where applicable and feasible. Applicability is generally assumed
if a feature exists or is proposed.
BMPs must be implemented for site design features where feasible. Leaving the box for a BMP unchecked means it will
not be implemented (either partially or fully) either because it is inapplicable or infeasible. Explanations must be provided
in the area below. The table provides specific instructions on when explanations are required.
Table 1 - Site Design Requirement
A. Existing Natural Site Features (see Fact Sheet BL-1)
1. Check the boxes below for each existing feature on
the site.
1. Select the BMPs to be implemented for each identified feature. Explain
why any BMP not selected is infeasible in the area below.
SD-G
Conserve natural
features
SD-H
Provide buffers around waterbodies
Natural waterbodies
Natural storage reservoirs & drainage corridors --
Natural areas, soils, & vegetation (incl. trees) --
B. BMPs for Common Impervious Outdoor Site Features (see Fact Sheet BL-2)
1. Check the boxes below for each
proposed feature.
2. Select the BMPs to be implemented for each proposed feature. If neither BMP SD-B nor
SD-I is selected for a feature, explain why both BMPs are infeasible in the area below.
SD-B
Direct runoff to pervious
areas
SD-I
Construct surfaces from
permeable materials
Minimize size of
impervious areas
X Streets and roads Check this box to confirm
that all impervious areas on
the site will be minimized
where feasible.
If this box is not checked,
identify the surfaces that
cannot be minimized in area
below, and explain why it is
infeasible to do so.
Sidewalks & walkways
Parking areas & lots
Driveways
Patios, decks, & courtyards
Hardcourt recreation areas
Other: _
C. BMPs for Rooftop Areas: Check this box if rooftop areas are proposed and select at least one BMP
below.
If no BMPs are selected, explain why they are infeasible in the area below.
(see Fact
Sheet BL-3)
SD-B
Direct runoff to pervious areas
SD-C
Install green roofs
SD-E
Install rain barrels
E-36 Page 1 of 3 Revised 10/21
E-36 Page 2 of 3 Revised 10/21
D. BMPs for Landscaped Areas: Check this box if landscaping is proposed and select the BMP below
X SD-K Sustainable Landscaping
If SD-K is not selected, explain why it is infeasible in the area below.
(see Fact
Sheet BL-4)
Provide discussion/justification for site design BMPs that will not be implemented (either partially or fully):
Baseline BMPs for Pollutant-generating Sources
All development projects must complete Table 2 - Source Control Requirement to identify applicable requirements for
documenting pollutant-generating sources/ features and source control BMPs.
BMPs must be implemented for source control features where feasible. Leaving the box for a BMP unchecked means it
will not be implemented (either partially or fully) either because it is inapplicable or infeasible. Explanations must be provided
in the area below. The table provides specific instructions on when explanations are required.
Table 2 - Source Control Requirement
A. Management of Storm Water Discharges
1. Identify all proposed outdoor
work areas below
X Check here if none are proposed
2. Which BMPs will be used to prevent
materials from contacting rainfall or
runoff?
(See Fact Sheet BL-5)
Select all feasible BMPs for each work area
3. Where will runoff from the
work area be routed?
(See Fact Sheet BL-6)
Select one or more option for each
work area
SC-A
Overhead
covering
SC-B
Separation
flows from
adjacent
areas
SC-C
Wind
protection
SC-D
Sanitary
sewer
SC-E
Containment
system
Other
Trash & Refuse Storage
Materials & Equipment Storage
Loading & Unloading
Fueling
Maintenance & Repair
Vehicle & Equipment Cleaning
Other: _ _
B. Management of Storm Water Discharges (see Fact Sheet BL-7)
Select one option for each feature below:
· Storm drain inlets and catch basins … are not proposed X will be labeled with stenciling or signage to
discourage dumping (SC-F)
· Interior work surfaces, floor drains &
sumps …
X are not proposed will not discharge directly or indirectly to the MS4
or receiving waters
· Drain lines (e.g. air conditioning, boiler,
etc.) …
X are not proposed will not discharge directly or indirectly to the MS4
or receiving waters
· Fire sprinkler test water … X are not proposed will not discharge directly or indirectly to the MS4
or receiving waters
Provide discussion/justification for source control BMPs that will not be implemented (either partially or fully):
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SUMMARY OF PDP STRUCTURAL BMPS
PDP Structural BMPs
All PDPs must implement structural BMPs for storm water pollutant control (see Chapter 5 of
the BMP Design Manual). Selection of PDP structural BMPs for storm water pollutant control
must be based on the selection process described in Chapter 5. PDPs subject to
hydromodification management requirements must also implement structural BMPs for flow
control for hydromodification management (see Chapter 6 of the BMP Design Manual). Both
storm water pollutant control and flow control for hydromodification management can be
achieved within the same structural BMP(s).
PDP structural BMPs must be verified by the City at the completion of construction. This may
include requiring the project owner or project owner's representative to certify construction of
the structural BMPs (see Section 1.12 of the BMP Design Manual). PDP structural BMPs must
be maintained into perpetuity, and the City must confirm the maintenance (see Section 7 of the
BMP Design Manual).
Use this form to provide narrative description of the general strategy for structural BMP
implementation at the project site in the box below. Then complete the PDP structural BMP
summary information sheet for each structural BMP within the project (copy the BMP summary
information page as many times as needed to provide summary information for each individual
structural BMP).
Describe the general strategy for structural BMP implementation at the site. This information
must describe how the steps for selecting and designing storm water pollutant control BMPs
presented in Section 5.1 of the BMP Design Manual were followed, and the results (type of
BMPs selected). For projects requiring hydromodification flow control BMPs, indicate whether
pollutant control and flow control BMPs are integrated together or separate.
Due to limited space, Tree Wells were selected, per Appendix E of the BMP Design
Manual to ensure that the contributing drainage area will meet flow control, stormwater
quality, and hydromodification requirements.
The improvements on Aviara Parkway are difficult to separate from the existing street
runoff. Therefore, the project will treat an equivalent area of existing pavement. The
proposed tree wells will accept runoff from the existing Laurel Tree Lane pavement (DMA
E1 = 10,090 sf impervious) , which is greater than the Aviara Parkway area (DMA P2 thru
P6 = 2,837 sf impervious). The proposed tree wells will meet the require treatment and
HMP mitigation for DMA P2 through P-6, which will not provide treatment and mitigation
for all of DMA E-1).
[Continue on next page as necessary.]
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[Continued from previous page – This page is reserved for continuation of description of general
strategy for structural BMP implementation at the site.]
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Structural BMP Summary Information
[Copy this page as needed to provide information for each individual proposed
structural BMP]
Structural BMP ID No. Tree Wells (15)
DWG 535-1 Sheet No. 5 & 6
Type of structural BMP:
Retention by harvest and use (HU-1)
Retention by infiltration basin (INF-1)
Retention by bioretention (INF-2)
Retention by permeable pavement (INF-3)
Dry Wells (INF-4)
Partial retention by biofiltration with partial retention (PR-1)
Biofiltration (BF-1)
Proprietary Biofiltration (BF-3)
Flow-thru treatment control included as pre-treatment/forebay for an onsite retention or
biofiltration BMP (provide BMP type/description and indicate which onsite retention or
biofiltration BMP it serves in discussion section below)
Detention pond or vault for hydromodification management
X Other (describe in discussion section below)
Purpose:
Pollutant control only
Hydromodification control only
X Combined pollutant control and hydromodification control
Pre-treatment/forebay for another structural BMP
Other (describe in discussion section below)
Discussion (as needed):
We are using tree wells (15 total) as described in the County of San Diego BMP manual to
provide treatment and HMP mitigation. Tree Well design methodology does not separate the
individual trees when providing treatment for large tributary areas.
1. The existing pavement area for DMA E-1 exceeds the area of DMA P2 Through P-6.
2. The Tree Wells provide treatment and HMP Mitigation for a maximum DCV of 749 CF.
3. The Required DCV for DMA P1 is 392, which leaves 357 cf, which exceeds the 138 cf required for
P2 through P-6.
ATTACHMENT 1
BACKUP FOR PDP POLLUTANT CONTROL BMPS
This is the cover sheet for Attachment 1.
Check which Items are Included behind this cover sheet:
Attachment
Sequence
Contents Checklist
Attachment 1a DMA Exhibit (Required)
See DMA Exhibit Checklist on the back of this
Attachment cover sheet. (24”x36” Exhibit
typically required)
X Included
Attachment 1b Tabular Summary of DMAs Showing DMA ID
matching DMA Exhibit, DMA Area, and DMA
Type (Required)*
*Provide table in this Attachment OR on DMA
Exhibit in Attachment 1a
Included on DMA
Exhibit in Attachment
1a
X Included as
Attachment 1b,
separate from DMA
Exhibit
Attachment 1c Form K-7, Harvest and Use Feasibility Screening
Checklist (Required unless the entire project will
use infiltration BMPs)
Refer to Appendix B of the BMP Design Manual
to complete Form K-7.
X Included
Not included because
the entire project will
use infiltration BMPs
Attachment 1d Infiltration Feasibility Analysis (Required unless
the project will use harvest and use BMPs)
Refer to Appendix D of the BMP Design Manual.
X Included
Not included because
the entire project will
use harvest and use
BMPs
Attachment 1e Pollutant Control BMP Design Worksheets /
Calculations (Required)
Refer to Appendices B, E, and I of the BMP
Design Manual for structural pollutant control and
significant site design BMP design guidelines
X Included
Attachment 1f Trash Capture BMP Design Calculations
(Required unless the entire project will use
permanent storm water quality basins)
Refer to Appendices J of the BMP Design Manual
for Trash capture BMP design guidelines
X Included
Not included because
the entire project will
use permanent storm
water quality basins
(i.e. infiltration,
biofiltration BMPs)
Use this checklist to ensure the required information has been included
on the DMA Exhibit:
The DMA Exhibit must identify:
X Underlying hydrologic soil group
X Approximate depth to groundwater
X Existing natural hydrologic features (watercourses, seeps, springs, wetlands)
X Critical coarse sediment yield areas to be protected (if present)
X Existing topography and impervious areas
X Existing and proposed site drainage network and connections to drainage offsite
X Proposed grading
X Proposed impervious features
X Proposed design features and surface treatments used to minimize imperviousness
X Drainage management area (DMA) boundaries, DMA ID numbers, and DMA areas (square
footage or acreage), and DMA type (i.e., drains to BMP, self-retaining, or self-mitigating)
X Structural BMPs (identify location and type of BMP)
X Tabular DMA Summary
INSERT MAP POCKET FOR DMA EXHIBIT (1a)
PLANNING ENGINEERING SURVEYING
3990 Ruffin Road, Suite 120
San Diego, Ca. 92123
858-560-1141
858-560-8157 Fax
DMA TOTAL
AREA IMPERVIOUS IMPERVIOUS PERVIOUS ADJUSTED
RUNOFF
EFFECTIVE
IMPERV AREA DCV REQ'D
FLOW
ACTUAL
FLOW
BMP TYPE /
STANDARD
NO (SF)(SF)(%)(SF)FACTOR (SF)(CF)RATE (CFS)RATE (CFS)
P2 1,431 450 31.4% 981 0.352 503 25 EQUIVALENT AREA
P3 1,326 622 46.9% 704 0.475 630 32 EQUIVALENT AREA
P4 722 722 100.0% - 0.900 650 33 EQUIVALENT AREA
P5 817 817 100.0% - 0.900 736 37 EQUIVALENT AREA
P6 547 225 41.1% 322 0.429 235 12 EQUIVALENT AREA
SUBTOTAL 4,844 2,837 58.6% 2,007 2,754 138
T1 6,698 -0.0% 6,698 0.100 670 33 TEMPORARY SLOPE
P1 8,712 8,712 100.0% - 0.900 7,841 392 TREE WELLS
E1 10,090 10,090 100.0% - 0.900 9,081 454 EQUIVALENT AREA
Project Name:Laurel Tree Lane Street WideningAttachment 1bTabular Summary of DMAsWorksheet B-1DMA Unique IdentifierArea (acres)Impervious Area (acres)% Imp HSGArea Weighted Runoff CoefficientDCV(cubic feet)Treated By (BMP ID)Pollutant Control TypeDrains to (POC ID)P20.0330.01031%A0.35225 EQUIVALENT AREAPOC-2P30.0300.01447%A0.47532 EQUIVALENT AREAPOC-2P40.0170.017100%A0.90033 -EQUIVALENT AREAPOC-2P50.0190.019100%A0.90037 EQUIVALENT AREAPOC-2P60.0130.00541%A0.42912 -EQUIVALENT AREAPOC-2SUBTOTAL0.1110.06559%A0.569138 -T10.1540.0000%A0.10033 TEMPORARY SLOPEPOC-3P10.2000.200100%A0.900392 TWPOC-1E10.2320.232100%A0.900454 TWEQUIVALENT AREAPOC-1TOTAL0.4320.432100%A0.900846 POC-1No. of DMAsTotal DMA Area (acres)Total Impervious Area (acres)% ImpArea Weighted Runoff CoefficientTotal DCV (cubic feet)Total Area Treated (acres)No. of POCs7 0.465 0.265 57% 0.556 563 0.311 3NOTES: 1. The DCV for DMA E-1 Exceeds the DCV for DMA P2 Through P-6. 2. The 15 Tree Wells provide treatment and HMP Mitigation for a maximum DCV of 749 CF.3. Required DCV for DMA P1 is 392, which leaves 357 cf, which exceeds the 138 cf required for P2 through P-6. Summary of DMA Information (Must match project description and SWQMP Narrative)Where: DMA = Drainage Management Area; Imp = Imperviousness; HSG = Hydrologic Soil Group; DCV= Design Capture Volume; BMP = Best Management Practice; POC = Point of Compliance; ID = identifier; No. = Number
HARVEST AND REUSE FORM (1c)
Laurel Tree Lane Attachment 1c
Harvest and Use Feasibility Checklist
Form I-7
1. Is there a demand for harvested water (check all that apply) at the project site that is reliably present during
the wet season?
X Toilet and urinal flushing: Employees/Visitors @ 9.3 gallons per person
X Landscape irrigation: Plant Factor @ Upper Moderate= 0.7/Hydrazone Mod = 1,470 gals in 36 hrs
Other:______ Irrigation Demand = 2.7 x [(0.7 x 1,470)/0.9] x 0.015 =46.3 cf/36-hrs/acre
Irrigation Demand per Modified ETWU Equation B.3-1 using General Landscape Type Hydazone
Moderate from Table B.3.3 and Moderate Plant Water Use – Table B.3.2
2. If there is a demand; estimate the anticipated average wet season demand over a period of 36 hours.
Guidance for planning level demand calculations for toilet/urinal flushing and landscape irrigation is provided
in Section B.3.2.
Site = people x 9.3 gals = 0 gals/day =0 gals per 36 hrs
Toilet Flushing Demand: 0 cubic-feet / 36 hours
Total Pervious Area = 0.024 ac x 46.3
Landscape Irrigation: 1 cubic feet / 36 hours
3. Calculate the DCV using worksheet B-2.1.
DCV = 518(cf) 25% = 130 cf
3a. Is the 36 hour demand greater
than or equal to the DCV?
Yes / No
3b. Is the 36 hour demand greater than
0.25DCV but less than the full DCV?
Yes / No
3c. Is the 36 hour demand
less than 0.25DCV?
Yes
Harvest and use appears to be
feasible. Conduct more detailed
evaluation and sizing calculations
to confirm that DCV can be used
at an adequate rate to meet
drawdown criteria.
Harvest and use may be feasible.
Conduct more detailed evaluation and
sizing calculations to determine
feasibility. Harvest and use may only be
able to be used for a portion of the site,
or (optionally) the storage may need to be
upsized to meet long term capture targets
while draining in longer than 36 hours.
Harvest and use is
considered to be infeasible.
Is harvest and use feasible based on further evaluation?
Yes, refer to Appendix E to select and size harvest and use BMPs.
No, select alternate BMPs.
Infiltration from (1d)
BMP design worksheets (1e)
trash capture calculations (1f)
ATTACHMENT 2
BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES
[This is the cover sheet for Attachment 2.]
Indicate which Items are Included behind this cover sheet:
Attachment
Sequence
Contents Checklist
Attachment 2a Hydromodification Management
Exhibit (Required)
See DMA Exhibit
X Included
See Hydromodification Management
Exhibit Checklist on the back of this
Attachment cover sheet.
Attachment 2b Management of Critical Coarse
Sediment Yield Areas (WMAA
Exhibit is required, additional
analyses are optional)
See Section 6.2 of the BMP Design
Manual.
X Exhibit showing project drainage
boundaries marked on WMAA
Critical Coarse Sediment Yield
Area Map (Required)
Optional analyses for Critical
Coarse Sediment Yield Area
Determination
Appendix H.6.1 Verification of
Geomorphic Landscape Units
Onsite
Appendix H.7 Downstream
Systems Sensitivity to Coarse
Sediment
Attachment 2c Geomorphic Assessment of
Receiving Channels (Optional)
See Section 6.3.4 of the BMP Design
Manual.
X Not performed
Included
Attachment 2d Flow Control Facility Design and
Structural BMP Drawdown
Calculations (Required)
See Chapter 6 and Appendix G of
the BMP Design Manual
X Not Applicable for Tree Wells
Use this checklist to ensure the required information has
been included on the
Hydromodification Management
Exhibit:
The Hydromodification Management Exhibit must identify:
X Underlying hydrologic soil group
X Approximate depth to groundwater
X Existing natural hydrologic features (watercourses, seeps, springs, wetlands)
X Critical coarse sediment yield areas to be protected (if present)
X Existing topography
X Existing and proposed site drainage network and connections to drainage offsite
X Proposed grading
X Proposed impervious features
X Proposed design features and surface treatments used to minimize imperviousness
X Point(s) of Compliance (POC) for Hydromodification Management
X Existing and proposed drainage boundary and drainage area to each POC (when
necessary, create separate exhibits for pre-development and post-project
conditions)
X Structural BMPs for hydromodification management (identify location, type
of BMP, and size/detail)
Hydromod exhibit
(see DMA exhibit)
Critical Course sediment (2b)
Laurel Tree Lane
Potential CCSYA
200 ft
N➤➤N
Geomorphic Assessment (2c) Excluded
flow control facility design and
Drawdown calculations
Not Applicable for Tree Wells
ATTACHMENT 3
Structural BMP Maintenance Information
Use this checklist to ensure the required information has been included in the Structural
BMP Maintenance Information Attachment:
Preliminary Design/Planning/CEQA level submittal:
Attachment 3 must identify:
X Typical maintenance indicators and actions for proposed structural BMP(s) based on Section
7.7 of the BMP Design Manual
Final Design level submittal:
Attachment 3 must identify:
X Specific maintenance indicators and actions for proposed structural BMP(s). This shall be
based on Section 7.7 of the BMP Design Manual and enhanced to reflect actual proposed
components of the structural BMP(s)
How to access the structural BMP(s) to inspect and perform maintenance
Features that are provided to facilitate inspection (e.g., observation ports, cleanouts, silt
posts, or other features that allow the inspector to view necessary components of the
structural BMP and compare to maintenance thresholds)
Manufacturer and part number for proprietary parts of structural BMP(s) when applicable
X Maintenance thresholds for BMPs subject to siltation or heavy trash(e.g., silt level posts or
other markings shall be included in all BMP components that will trap and store sediment, trash,
and/or debris, so that the inspector may determine how full the BMP is, and the maintenance
personnel may determine where the bottom of the BMP is . If required, posts or other markings
shall be indicated and described on structural BMP plans.)
X Recommended equipment to perform maintenance
X When applicable, necessary special training or certification requirements for inspection and
maintenance personnel such as confined space entry or hazardous waste management
SD-1
Tree Wells
BMP MAINTENANCE FACT SHEET
FOR
SITE DESIGN BMP SD-1 TREE WELLS
Tree wells as site design BMPs are trees planted in configurations that allow storm water runoff to be directed into
the soil immediately surrounding the tree. The tree may be contained within a planter box or structural cells. The
surrounding area will be graded to direct runoff to the tree well. There may be features such as tree grates,
suspended pavement design, or shallow surface depressions designed to allow runoff into the tree well. Typical
tree well components include:
• Trees of the appropriate species for site conditions and constraints
• Available growing space based on tree species, soil type, water availability, surrounding land uses, and
project goals
• Entrance/opening that allows storm water runoff to flow into the tree well (e.g., a curb opening, tree
grate, or surface depression)
• Optional suspended pavement design to provide structural support for adjacent pavement without
requiring compaction of underlying layers
• Optional root barrier devices as needed; a root barrier is a device installed in the ground, between a tree
and the sidewalk, intended to guide roots down and away from the sidewalk in order to prevent sidewalk
lifting from tree roots
• Optional tree grates; to be considered to maximize available space for pedestrian circulation and to
protect tree roots from compaction related to pedestrian circulation; tree grates are typically made up of
porous material that will allow the runoff to soak through
• Optional shallow surface depression for ponding of excess runoff
• Optional planter box drain
Normal Expected Maintenance
Tree health shall be maintained as part of normal landscape maintenance. Additionally, ensure that storm water
runoff can be conveyed into the tree well as designed. That is, the opening that allows storm water runoff to flow
into the tree well (e.g., a curb opening, tree grate, or surface depression) shall not be blocked, filled, re-graded, or
otherwise changed in a manner that prevents storm water from draining into the tree well. A summary table of
standard inspection and maintenance indicators is provided within this Fact Sheet.
Non-Standard Maintenance or BMP Failure
Tree wells are site design BMPs that normally do not require maintenance actions beyond routine landscape
maintenance. The normal expected maintenance described above ensures the BMP functionality. If changes have
been made to the tree well entrance / opening such that runoff is prevented from draining into the tree well (e.g.,
a curb inlet opening is blocked by debris or a grate is clogged causing runoff to flow around instead of into the tree
well, or a surface depression has been filled so runoff flows away from the tree well), the BMP is not performing as
intended to protect downstream waterways from pollution and/or erosion. Corrective maintenance will be
required to restore drainage into the tree well as designed.
Surface ponding of runoff directed into tree wells is expected to infiltrate/evapotranspirate within 24-96 hours
following a storm event. Surface ponding longer than approximately 24 hours following a storm event may be
detrimental to vegetation health, and surface ponding longer than approximately 96 hours following a storm event
poses a risk of vector (mosquito) breeding. Poor drainage can result from clogging or compaction of the soils
surrounding the tree. Loosen or replace the soils to restore drainage.
SD-1 Page 1 of 6
January 12, 2017
SD-1
Tree Wells
Other Special Considerations
Site design BMPs, such as tree wells, installed within a new development or redevelopment project are
components of an overall storm water management strategy for the project. The presence of site design BMPs
within a project is usually a factor in the determination of the amount of runoff to be managed with structural
BMPs (i.e., the amount of runoff expected to reach downstream retention or biofiltration basins that process
storm water runoff from the project as a whole). When site design BMPs are not maintained or are removed, this
can lead to clogging or failure of downstream structural BMPs due to greater delivery of runoff and pollutants than
intended for the structural BMP. Therefore, the [City Engineer] may require confirmation of maintenance of site
design BMPs as part of their structural BMP maintenance documentation requirements. Site design BMPs that
have been installed as part of the project should not be removed, nor should they be bypassed by re-routing roof
drains or re-grading surfaces within the project. If changes are necessary, consult the [City Engineer] to determine
requirements.
SD-1 Page 2 of 6
January 12, 2017
SD-1
Tree Wells
SUMMARY OF STANDARD INSPECTION AND MAINTENANCE FOR SD-1 TREE WELLS
The property owner is responsible to ensure inspection, operation and maintenance of permanent BMPs on their property unless responsibility has been formally transferred to
an agency, community facilities district, homeowners association, property owners association, or other special district.
Maintenance frequencies listed in this table are average/typical frequencies. Actual maintenance needs are site-specific, and maintenance may be required more frequently.
Maintenance must be performed whenever needed, based on maintenance indicators presented in this table. The BMP owner is responsible for conducting regular inspections
to see when maintenance is needed based on the maintenance indicators. During the first year of operation of a structural BMP, inspection is recommended at least once prior
to August 31 and then monthly from September through May. Inspection during a storm event is also recommended. After the initial period of frequent inspections, the
minimum inspection and maintenance frequency can be determined based on the results of the first year inspections.
Threshold/Indicator Maintenance Action Typical Maintenance Frequency
Tree health Routine actions as necessary to maintain tree health. • Inspect monthly.
• Maintenance when needed.
Dead or diseased tree Remove dead or diseased tree. Replace per original
plans.
• Inspect monthly.
• Maintenance when needed.
Standing water in tree well for longer than 24 hours
following a storm event
Surface ponding longer than approximately 24 hours
following a storm event may be detrimental to tree
health
Loosen or replace soils surrounding the tree to restore
drainage.
• Inspect monthly and after every 0.5-inch or larger
storm event. If standing water is observed, increase
inspection frequency to after every 0.1-inch or larger
storm event.
• Maintenance when needed.
Presence of mosquitos/larvae
For images of egg rafts, larva, pupa, and adult
mosquitos, see
http://www.mosquito.org/biology
Disperse any standing water from the tree well to
nearby landscaping. Loosen or replace soils surrounding
the tree to restore drainage (and prevent standing
water).
• Inspect monthly and after every 0.5-inch or larger
storm event. If mosquitos are observed, increase
inspection frequency to after every 0.1-inch or larger
storm event.
• Maintenance when needed
Entrance / opening to the tree well is blocked such that
storm water will not drain into the tree well (e.g., a curb
inlet opening is blocked by debris or a grate is clogged
causing runoff to flow around instead of into the tree
well; or a surface depression is filled such that runoff
drains away from the tree well)
Make repairs as appropriate to restore drainage into the
tree well.
• Inspect monthly.
• Maintenance when needed.
SD-1 Page 3 of 6
January 12, 2017
SD-1
Tree Wells
References
American Mosquito Control Association.
http://www.mosquito.org/
County of San Diego. 2014. Low Impact Development Handbook.
http://www.sandiegocounty.gov/content/sdc/dpw/watersheds/susmp/lid.html
San Diego County Copermittees. 2016. Model BMP Design Manual, Appendix E, Fact Sheet SD-1.
http://www.projectcleanwater.org/index.php?option=com_content&view=article&id=250&Itemid=220
SD-1 Page 4 of 6
January 12, 2017
SD-1
Tree Wells
Date: Inspector: BMP ID No.:
Permit No.: APN(s):
Property / Development Name:
Responsible Party Name and Phone Number:
Property Address of BMP:
Responsible Party Address:
INSPECTION AND MAINTENANCE CHECKLIST FOR SD-1 TREE WELLS PAGE 1 of 2
Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted
Dead or diseased tree
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Remove dead or diseased tree
☐ Replace per original plans
☐ Other / Comments:
Standing water in tree well for longer than 24
hours following a storm event
Surface ponding longer than approximately 24
hours following a storm event may be
detrimental to tree health
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Loosen or replace soils surrounding the
tree to restore drainage
☐ Other / Comments:
SD-1 Page 5 of 6
January 12, 2017
SD-1
Tree Wells
Date: Inspector: BMP ID No.:
Permit No.: APN(s):
INSPECTION AND MAINTENANCE CHECKLIST FOR SD-1 TREE WELLS PAGE 2 of 2
Threshold/Indicator Maintenance Recommendation Date Description of Maintenance Conducted
Presence of mosquitos/larvae
For images of egg rafts, larva, pupa, and adult
mosquitos, see
http://www.mosquito.org/biology
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Disperse any standing water from the tree
well to nearby landscaping
☐ Loosen or replace soils surrounding the
tree to restore drainage (and prevent
standing water)
☐ Other / Comments:
Entrance / opening to the tree well is blocked
such that storm water will not drain into the
tree well (e.g., a curb inlet opening is blocked by
debris or a grate is clogged causing runoff to
flow around instead of into the tree well; or a
surface depression is filled such that runoff
drains away from the tree well)
Maintenance Needed?
☐ YES
☐ NO
☐ N/A
☐ Make repairs as appropriate to restore
drainage into the tree well
☐ Other / Comments:
SD-1 Page 6 of 6
January 12, 2017
ATTACHMENT 4
City standard Single Sheet BMP (SSBMP) Exhibit
[Use the City’s standard Single Sheet BMP Plan.]
Plotted: 3/25/2022 11:26 AM D:\76582 AVIARA APTS\03 DWG\SI\76582SI12-SI13.DWG - tony.pQUARTERLY QUARTERLY
BMP CONSTRUCTION AND INSPECTION NOTES:
THE EOW WILL VERIFY THAT PERMANENT BMPS ARE CONSTRUCTED
AND OPERATING IN COMPLIANCE WITH THE APPLICABLE
REQUIREMENTS. PRIOR TO OCCUPANCY, THE EOW MUST PROVIDE:
1.PHOTOGRAPHS OF THE INSTALLATION OF PERMANENT BMPS
PRIOR TO CONSTRUCTION, DURING CONSTRUCTION, AND AT
FINAL INSTALLATION.
2.A WET STAMPED LETTER VERIFYING THAT PERMANENT BMPS
ARE CONSTRUCTED AND OPERATING PER THE REQUIREMENTS
OF THE APPROVED PLANS.
3.PHOTOGRAPHS TO VERIFY THAT PERMANENT WATER QUALITY
TREATMENT SIGNAGE HAS BEEN INSTALLED.
PRIOR TO RELEASE OF SECURITIES, THE DEVELOPER IS RESPONSIBLE
FOR ENSURING THE PERMANENT BMPS HAVE NOT BEEN REMOVED OR
MODIFIED BY THE NEW HOMEOWNER OR HOA WITHOUT THE
APPROVAL OF THE CITY ENGINEER.
FILTER
INLET
1. THESE BMPS ARE MANDATORY TO BE INSTALLED PER MANUFACTURER'S
RECOMMENDATIONS OR THESE PLANS.
2. NO CHANGES TO THE PROPOSED BMPS ON THIS SHEET WITHOUT PRIOR
APPROVAL FROM THE CITY ENGINEER.
3. NO SUBSTITUTIONS TO THE MATERIAL OR TYPES OR PLANTING TYPES
WITHOUT PRIOR APPROVAL FROM THE CITY ENGINEER.
4. NO OCCUPANCY WILL BE GRANTED UNTIL THE CITY INSPECTION STAFF
HAS INSPECTED THIS PROJECT FOR APPROPRIATE BMP CONSTRUCTION
AND INSTALLATION.
BMP NOTES:
PARTY RESPONSIBLE FOR MAINTENANCE:
NAME
ADDRESS
PHONE NO.
CONTACT
PLAN PREPARED BY:
NAME
ADDRESS
PHONE NO.
CERTIFICATION
COMPANY
TC-50
LOW IMPACT DESIGN (L.I.D.)
SOURCE CONTROL
HYDROMODIFICATION & TREATMENT CONTROL
5. REFER TO MAINTENANCE AGREEMENT DOCUMENT.
4 EA.444-4A 3, 4, 5
STENCILS SD-13
6. SEE PROJECT SWMP FOR ADDITIONAL INFORMATION.
SIGNATURE
PLANNING ENGINEERING SURVEYING3990 Ruffin Road, Suite 120
San Diego, Ca. 92123
858-560-1141
858-560-8157 Fax
AVIARA, LP
RENEE B. POWELL
SB&O INC.
3990 RUFFIN ROAD
SUITE 120
SAN DIEGO, CA. 92123
(858) 560-1141
3444 CAMINO DEL RIO NORTH
#202
SAN DIEGO, CA. 92108
DENNIS SZUBERLA
(858) 535-1475
BMP TABLE
1 TREE WELL QUARTERLYSD-1 15 EA.535-1 5-6 AS NEEDED
2
3 NO DUMPING
DRAINS TOOCEAN
2 3