SP22-0003_Staff Report_Attach B4_Appx J_ SWQMP West — San Marcos City Council, October 24, 2023

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023

CITY OF SAN MARCOS

PRIORITY DEVELOPMENT PROJECT (PDP)

STORM WATER QUALITY MANAGEMENT PLAN (SWQMP)
FOR

MARCOS SPECIFIC PLAN WESTEND
TSM #22-0002

GRAND AVENUE AND LINDA VISTA DRIVE

SAN MARCOS, CA

ASSESSOR'S PARCEL NUMBER(S):
219-152-70, -74, -76, -77, -79
ENGINEER OF WORK:

___________________________________________________________________________________ KENNETH T. KOZLIK, PE C71883

PREPARED FOR:

CALIFORNIA PACIFIC HOMES, INC.
5251 CALIFORNIA AVENUE, SUITE 250
IRVINE, CA 92617
949-833-6104

PDP SWQMP PREPARED BY:

FUSCOE ENGINEERING, INC.
6390 GREENWICH DRIVE, SUITE 170
SAN DIEGO, CA 92122
858-554-1500

DATE OF SWQMP:

May 12, 2023

PLANS PREPARED BY:

FUSCOE ENGINEERING, INC.
6390 GREENWICH DRIVE, SUITE 170
SAN DIEGO, CA 92122
858-554-1500

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
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City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023

TABLE OF CONTENTS

Acronym Sheet
PDP SWQMP Preparer's Certification Page
PDP SWQMP Project Owner's Certification Page
Submittal Record
Project Vicinity Map
FORM I-1 Applicability of Storm Water BMP Requirements
FORM I-2 Project Type Determination Checklist (Standard Project or PDP) FORM I-3B Site Information Checklist for PDPs
FORM I-4 Source Control BMP Checklist for All Development Projects FORM I-5 Site Design BMP Checklist for All Development Projects FORM I-6 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: Categorization of Infiltration Feasibility Condition (when applicable) Attachment 1e: Pollutant Control BMP Design Worksheets / Calculations 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 Plan
Attachment 3a: B Structural BMP Maintenance Thresholds and Actions Attachment 3b: Draft Maintenance Agreement (when applicable) Attachment 4: Copy of Plan Sheets Showing Permanent Storm Water BMPs

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023

ACRONYMS

APN Assessor's Parcel Number
BMP Best Management Practice
HMP Hydromodification Management Plan
HSG Hydrologic Soil Group
MS4 Municipal Separate Storm Sewer System
N/A Not Applicable
NRCS Natural Resources Conservation Service
PDP Priority Development Project
PE Professional Engineer
SC Source Control
SD Site Design
SDRWQCB San Diego Regional Water Quality Control Board
SIC Standard Industrial Classification
SWQMP Storm Water Quality Management Plan

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
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City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
PDP SWQMP PROJECT OWNER'S CERTIFICATION PAGE – CALIFORNIA PACIFIC HOMES, INC.

Project Name: MARCOS SPECIFIC PLAN
Permit Application Number: [Insert Permit Application Number]

PROJECT OWNER'S CERTIFICATION

This PDP SWQMP has been prepared for CALIFORNIA PACIFIC HOMES, INC. by Fuscoe Engineering, Inc.

The PDP SWQMP is intended to comply with the PDP requirements of the City of San Marcos BMP Design Manual, which is a design manual for compliance with local City of San Marcos and regional MS4 Permit (California Regional Water Quality Control Board San Diego Region Order No. R9-2015-0100) requirements for storm water management.

The undersigned, while it owns the subject property, is responsible for the implementation of the provisions of this plan. Once the undersigned transfers its interests in the property, its successor-in- interest shall bear the aforementioned responsibility to implement the best management practices (BMPs) described within this plan, including ensuring on-going operation and maintenance of structural BMPs. A signed copy of this document shall be available on the subject property into perpetuity.

________________________________________________________ Project Owner's Signature

________________________________________________________ Print Name

________________________________________________________ Company

____________________________
Date

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SUBMITTAL RECORD

Use this Table to keep a record of submittals of this PDP SWQMP. Each time the PDP SWQMP is re- submitted, provide the date and status of the project. In column 4 summarize the changes that have been made or indicate if response to plancheck comments is included. When applicable, insert response to plancheck comments behind this page.

Submittal
Number
Date Project Status Summary of Changes
1 March 11, 2022  Preliminary Design /
Planning/ CEQA
 Final Design
Initial Submittal
2 October 11, 2022  Preliminary Design /
Planning/ CEQA
 Final Design
Second Submittal
3 December 19,
2022
 Preliminary Design /
Planning/ CEQA
 Final Design
Third Submittal
4 March 14, 2023  Preliminary Design /
Planning/ CEQA
 Final Design
Fourth Submittal
5 May 12, 2023  Preliminary Design /
Planning/ CEQA
 Final Design
Fifth Submittal

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023

PROJECT VICINITY MAP

Project Name: MARCOS SPECIFIC PLAN
Permit Application Number: [Insert Permit Application Number]

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Applicability of Storm Water Best Management Practices (BMP) Requirements (Storm Water Intake Form for all Development Permit Applications) For detailed information please visit:
http://www.san-marcos.net/departments/development-services/stormwater/development-planning Form I-1
[March 15, 2016]
Project Identification
Project Name: Marcos Specific Plan
Description:

Proposed mixed-use development incorporating commercial and multi-family residential uses.

Permit Application Number (if applicable): Date: 5/12/2023 Project Address: Grand Avenue and Linda Vista Drive
Determination of Requirements
This form is required as part of the City’s application process. The purpose of this form is to identify potential land development planning storm water requirements that apply to development projects.

Development projects are defined as construction, rehabilitation, redevelopment, or reconstruction of any public or private projects. In addition, the identification of a development project, as it relates to storm water regulations, would truly apply to development and redevelopment activities that have the potential to contact storm water and contribute a source of pollutants, or reduce the natural absorption and infiltration abilities of the land.

To access the BMP Design Manual, Storm Water Quality Management Plan (SWQMP) templates, and other pertinent information related to this program please refer to:
http://www.san-marcos.net/departments/development-services/stormwater/development-planning

Please answer each of the following steps below, starting with Step 1 and progressing through each step until reaching "Stop".

Step Answer Progression
Step 1: Based on the above, Is the project a
"development project" (See definition above)?
See Section 1.3 of the BMP Design Manual for
further guidance if necessary.
 Yes Go to Step 2.
 No Permanent BMP requirements do not apply. No
SWQMP will be required. Provide brief discussion
below. STOP.

Discussion / justification if the project is not a "development project" (e.g., the project includes only interior remodels within an existing building):

Step 2: Is the project a Standard Project, Priority
Development Project (PDP), or exception to PDP
definitions?

To answer this item, complete Form I-2, Project
Type Determination. See Section 1.4 of the BMP
Design Manual in its entirety for guidance.

In addition to Section 1.4, please refer to the
City’s SWQMP Submittal Requirements form.

 Standard Project Only Standard Project requirements apply, including Standard Project SWQMP. STOP.
 PDP Standard and PDP requirements apply, including
PDP SWQMP. Go to Step 3 on the following page.
 Exception to PDP
definitions
Standard Project requirements apply, and any
additional requirements specific to the type of
project. Provide discussion and list any additional
requirements below. Prepare Standard Project
SWQMP. STOP.

Discussion / justification, and additional requirements for exceptions to PDP definitions, if applicable:

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Form I-1 Page 2, Form Date: March 15, 2016
Step 3 (PDPs only). Please answer the list of questions in this section to determine if hydromodification requirements reply to the proposed PDP. Does the project:

Step 3a. Discharge storm water
runoff directly to the Pacific Ocean?
 Yes STOP. Hydromodification requirements do not apply.  No Continue to Step 3b.

Step 3b. Discharge storm water
runoff directly to an enclosed
embayment, not within protected
areas?
 Yes STOP. Hydromodification requirements do not apply.  No Continue to Step 3c.

Step 3c. Discharge storm water
runoff directly to a water storage
reservoir or lake, below spillway or
normal operating level?
 Yes STOP. Hydromodification requirements do not apply.  No Continue to Step 3d.

Step 3d. Discharge storm water
runoff directly to an area identified in
WMAA?
 Yes STOP. Hydromodification requirements do not apply.  No Hydromodification requirements apply to the project. Go to Step

4. Discussion / justification if hydromodification control requirements do not apply:

Step 4 (PDPs subject to
hydromodification control
requirements only). Does protection
of critical coarse sediment yield areas
apply based on review of WMAA
Potential Critical Coarse Sediment
Yield Area Map?
See Section 6.2 of the BMP Design
Manual for guidance.

 Yes Management measures required for protection of critical coarse sediment yield areas (Chapter 6.2).

Stop.
 No Management measures not required for protection of critical coarse sediment yield areas.

Provide brief discussion below.

Stop.

Project site is not identified as a Potential Critical Course Sediment Yield Area

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Project Type Determination Checklist Form I-2
[March 15, 2016]
Project Information
Project Name/Description: Marcos Specific Plan
Permit Application Number (if applicable): Date: 10/11/2022 Project Address: Grand Avenue and Linda Vista Drive
Project Type Determination: Standard Project or Priority Development Project (PDP) The project is (select one):  New Development  Redevelopment The total proposed newly created or replaced impervious area is: 155,750 ft2 (3.58 acres) Is the project in any of the following categories, (a) through (f)? Yes

No

(a) New development projects that create 10,000 square feet or more of impervious surfaces (collectively over the entire project site). This includes commercial, industrial, residential, mixed-use, and public development projects on public or private land.

Yes

No

(b) Redevelopment projects that create and/or replace 5,000 square feet or more of impervious surface (collectively over the entire project site on an existing site of 10,000 square feet or more of impervious surfaces). This includes commercial, industrial, residential, mixed-use, and public development projects on public or private land.

Yes

No

(c) New and redevelopment projects that create and/or replace 5,000 square feet or more of impervious surface (collectively over the entire project site), and support one or more of the following uses:

Restaurants. This category is defined as 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 (Standard Industrial Classification (SIC) code 5812).

Hillside development projects. This category includes development on any natural slope that is twenty-five percent or greater.

Parking lots. This category is defined as a land area or facility for the temporary parking or storage of motor vehicles used personally, for business, or for commerce.

Streets, roads, highways, freeways, and driveways. This category is defined as any paved impervious surface used for the transportation of automobiles, trucks, motorcycles, and other vehicles.

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Form I-2 Page 2, Form Date: March 15, 2016
Yes

No

(d) New or redevelopment projects that create and/or replace 2,500 square feet or more of impervious surface (collectively over the entire project site), and discharging directly to an Environmentally Sensitive Area (ESA). “Discharging directly to” includes flow that is conveyed overland a distance of 200 feet or less from the project to the ESA, or conveyed in a pipe or open channel any distance as an isolated flow from the project to the ESA (i.e. not commingled with flows from adjacent lands).

Note: ESAs are areas that include but are not limited to all Clean Water Act Section 303(d) impaired water bodies; areas designated as Areas of Special Biological Significance by the State Water Board and San Diego Water Board; State Water Quality Protected Areas; water bodies designated with the RARE beneficial use by the State Water Board and San Diego Water Board; and any other equivalent environmentally sensitive areas which have been identified by the Copermittees. See BMP Design Manual Section 1.4.2 for additional guidance.

Yes

No

(e) New development projects, or redevelopment projects that create and/or replace 5,000 square feet or more of impervious surface, that support one or more of the following uses:
(i) Automotive repair shops. This category is defined as a facility that is categorized in any one of the following SIC codes: 5013, 5014, 5541, 7532- 7534, or 7536-7539.
(ii) Retail gasoline outlets (RGOs). This category includes RGOs that meet the following criteria: (a) 5,000 square feet or more or (b) a projected Average Daily Traffic (ADT) of 100 or more vehicles per day.

Yes

No

(f) New or redevelopment projects that result in the disturbance of one or more acres of land and are expected to generate pollutants post construction.

Note: See BMP Design Manual Section 1.4.2 for additional guidance.

Does the project meet the definition of one or more of the Priority Development Project categories (a) through (f) listed above?
 No – the project is not a Priority Development Project (Standard Project).  Yes – the project is a Priority Development Project (PDP).

The following is for redevelopment PDPs only:

The area of existing (pre-project) impervious area at the project site is: 12,216 ft2 (A) The total proposed newly created or replaced impervious area is 155,750ft2 (B) Percent impervious surface created or replaced (B/A)*100: 1275% The percent impervious surface created or replaced is (select one based on the above calculation):
 less than or equal to fifty percent (50%) – only new impervious areas are considered PDP OR
 greater than fifty percent (50%) – the entire project site is a PDP

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
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Site Information Checklist
For PDPs
Form I-3B (PDPs)
[March 15, 2016]
Project Summary Information
Project Name Marcos Specific Plan
Project Address Grand Avenue and Linda Vista Drive

Assessor's Parcel Number(s) (APN(s)) 219-152-70, -74, -76, -77, -79 Permit Application Number
Project Hydrologic Unit Select One:
 Santa Margarita 902
 San Luis Rey 903
 Carlsbad 904
 San Dieguito 905
 Penasquitos 906
 San Diego 907
 Pueblo San Diego 908
 Sweetwater 909
 Otay 910
 Tijuana 911
Project Watershed
(Complete Hydrologic Unit, Area, and Subarea
Name with Numeric Identifier)
Carlsbad Hydrologic Unit, San Marcos Hydrologic
Area, Richland Hydrologic Sub-Area, 904.52
Parcel Area
(total area of Assessor's Parcel(s) associated
with the project)

4.73 Acres (206,040 Square Feet)
Area to be Disturbed by the Project
(Project Area)

5.03 Acres (219,274 Square Feet)
Project Proposed Impervious Area
(subset of Project Area)

3.86 Acres (167,966 Square Feet)
Project Proposed Pervious Area
(subset of Project Area)

0.98 Acres (42,745 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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Form I-3B Page 2 of 10, Form Date: March 15, 2016
Description of Existing Site Condition
Current Status of the Site (select all that apply):
 Existing development
 Previously graded but not built out
 Demolition completed without new construction
 Agricultural or other non-impervious use
 Vacant, undeveloped/natural

Description / Additional Information:

The project site was previously developed with commercial/industrial uses. The buildings have since been demolished, but portions of building slabs and paved parking areas remain.

Existing Land Cover Includes (select all that apply):
 Vegetative Cover
 Non-Vegetated Pervious Areas
 Impervious Areas

Description / Additional Information:

The project site was previously developed with commercial/industrial uses. The buildings have since been demolished, but portions of building slabs and paved parking areas remain.

Underlying Soil belongs to Hydrologic Soil Group (select all that apply):
 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
 GW Depth > 20 feet

Existing Natural Hydrologic Features (select all that apply):
 Watercourses
 Seeps
 Springs
 Wetlands
 None

Description / Additional Information:

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
Form I-3B Page 3 of 10, Form Date: March 15, 2016
Description of Existing Site Drainage Patterns
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) Is runoff from offsite conveyed through the site? if yes, quantify all offsite drainage areas, design flows, and locations where offsite flows enter the project site, and summarize how such flows are conveyed through the site;
(3)Provide details regarding existing project site drainage conveyance network, including any existing storm drains, concrete channels, swales, detention facilities, storm water treatment facilities, natural or constructed channels; and
(4) Identify all discharge locations from the existing project site along with a summary of conveyance system size and capacity for each of the discharge locations. Provide summary of the pre-project drainage areas and design flows to each of the existing runoff discharge locations.

Describe existing site drainage patterns:

The existing site consists of development areas that were previously commercial pads but have had the buildings demolished. From an aerial view, the site visually appear flat. The channel was recently improved by the City of San Marcos (CIP Project Code 88214, “Grand Avenue Drainage / Road Improvements”, IP-4826 and VWD no. 201930). The development area had new storm drain added to collect runoff from the pads and discharge into the improved channel. A bridge was constructed to link to the neighboring development site, east of this site.

Upon closer inspection of the topography, one can see that there are some subtle flow paths where the site drains to the storm drain outlets that were constructed as part of the channel improvements at nodes 200 and 400. The westerly third of the residential site leads to a local depression near node 10 before spilling out onto the adjacent property to the west.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
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Form I-3B Page 4 of 10, Form Date: March 15, 2016
Description of Proposed Site Development
Project Description / Proposed Land Use and/or Activities:

This project consists of approximately 5.03 acres near the southwest corner of the Linda Vista Drive and Grand Avenue intersection in the city of San Marcos, California. Located at the north of the channel, the site will be used to develop 102 residential condominiums.

List/describe proposed impervious features of the project (e.g., buildings, roadways, parking lots, courtyards, athletic courts, other impervious features):

Impervious areas will include buildings; vehicular paving in drive aisles and parking areas; and pedestrian pavement for sidewalk, bike paths, and walkways.

List/describe proposed pervious features of the project (e.g., landscape areas):

The project will include extensive landscape areas. Decomposed granite (DG) is also proposed for some parking spaces and walkways. As a conservative approach for BMP sizing, the DG areas were assumed to be impervious.

Does the project include grading and changes to site topography?  Yes
 No

Description / Additional Information:

The project will be graded support drainage of the proposed project area to the storm water BMPs and the creek.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
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Form I-3B Page 5 of 10, Form Date: March 15, 2016
Description of Proposed Site Drainage Patterns
Does the project include changes to site drainage (e.g., installation of new storm water conveyance systems)?
 Yes
 No

If yes, provide details regarding the proposed project site drainage conveyance network, including storm drains, concrete channels, swales, detention facilities, storm water treatment facilities, natural or constructed channels, and the method for conveying offsite flows through or around the proposed project site. Identify all discharge locations from the proposed project site along with a summary of the conveyance system size and capacity for each of the discharge locations. Provide a summary of pre- and post-project drainage areas and design flows to each of the runoff discharge locations. Reference the drainage study for detailed calculations.

Describe proposed site drainage patterns::

The proposed development areas will be re-graded to ensure that the runoff is routed to the channel. The site has a system of concrete swales and storm drains to collect runoff and convey it to water quality basins and/or underground detention structures for hydromodification storage before being discharged to the channel at nodes 200, 400 and 1000.

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Form I-3B Page 6 of 10, Form Date: March 15, 2016
Identify whether any of the following features, activities, and/or pollutant source areas will be present (select all that apply):
 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
 Plazas, sidewalks, and parking lots

Description / Additional Information:

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
Form I-3B Page 7 of 10, Form Date: March 15, 2016
Identification and Narrative of Receiving Water and Pollutants of Concern Describe flow path of storm water from the project site discharge location(s), through urban storm conveyance systems as applicable, to receiving creeks, rivers, and lagoons as applicable, and ultimate discharge to the Pacific Ocean (or bay, lagoon, lake or reservoir, as applicable):

Discharge from the site enters the unnamed creek with runs southwest through the site. The creek continues to flow southwest to a confluence with San Marcos Creek just upstream of Lake San Marcos.

San Marcos Creek discharges to Batiquitos Lagoon, which is tidally connected to the Pacific Ocean.

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 and/or Highest Priority Pollutants from the WQIP for the impaired water bodies:
303(d) Impaired Water Body Pollutant(s)/Stressor(s)
TMDLs / WQIP Highest Priority
Pollutant
San Marcos Creek DDE, Phosphorous, Sediment
Toxicity, Selenium
DDE, Phosphorous, Sediment
Toxicity, Selenium
San Marcos Lake Ammonia Nitrogen, Nutrients Ammonia Nitrogen, Nutrients

Identification of Project Site Pollutants*
*Identification of project site pollutants is only required if flow-thru treatment BMPs are implemented onsite in lieu of retention or biofiltration BMPs (note the project must also participate in an alternative compliance program unless prior lawful approval to meet earlier PDP requirements is demonstrated)
Identify pollutants expected from the project site based on all proposed use(s) of the site (see BMP Design Manual Appendix B.6):

Pollutant
Not Applicable to the
Project Site
Expected from the
Project Site
Also a Receiving Water
Pollutant of Concern
Sediment X X
Nutrients X X
Heavy Metals X X
Organic Compounds

X
Trash & Debris X
Oxygen Demanding
Substances X
Oil & Grease X
Bacteria & Viruses X
Pesticides X

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Form I-3B Page 8 of 10, Form Date: March 15, 2016
Hydromodification Management Requirements
Do hydromodification management requirements apply (see Section 1.6 of the BMP Design Manual)?  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):

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
 No, No critical coarse sediment yield areas to be protected based on WMAA maps

If yes, have any of the optional analyses presented in Section 6.2 of the BMP Design Manual been performed?
 6.2.1 Verification of Geomorphic Landscape Units (GLUs) Onsite  6.2.2 Downstream Systems Sensitivity to Coarse Sediment  6.2.3 Optional Additional Analysis of Potential Critical Coarse Sediment Yield Areas Onsite  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 2.b of the SWQMP.  Critical coarse sediment yield areas exist and require protection. The project will implement management measures described in Sections 6.2.4 and 6.2.5 as applicable, and the areas are identified on the SWQMP Exhibit.

Discussion / Additional Information:

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
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Form I-3B Page 9 of 10, Form Date: March 15, 2016
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.

Has a geomorphic assessment been performed for the receiving channel(s)?  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:

The receiving channel has been restored and is an actively managed conservation area, which will ensure erosion impacts will be minimal.

Discussion / Additional Information: (optional)

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
Form I-3B Page 10 of 10, Form Date: March 15, 2016
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 local codes governing minimum street width, sidewalk construction, allowable pavement types, and drainage requirements.

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.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
X
X
X
X
Source Control BMP Checklist
for All Development Projects
(Standard Projects and Priority Development Projects)
Form I-4
[March 15, 2016]
Project Identification
Project Name: Marcos Specific Plan
Permit Application Number
Source Control BMPs
All development projects must implement source control BMPs SC-1 through SC-6 where applicable and feasible. See Chapter 4 and Appendix E of the Model BMP Design Manual for information to implement source control BMPs shown in this checklist.

Answer each category below pursuant to the following.
 "Yes" means the project will implement the source control BMP as described in Chapter 4 and/or Appendix E of the Model BMP Design Manual. Discussion / justification is not required.  "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion / justification must be provided.
 "N/A" means the BMP is not applicable at the project site because the project does not include the feature that is addressed by the BMP (e.g., the project has no outdoor materials storage areas).

Discussion / justification may be provided.

Source Control Requirement Applied?
SC-1 Prevention of Illicit Discharges into the MS4  Yes  No  N/A Discussion / justification if SC-1 not implemented:

SC-2 Storm Drain Stenciling or Signage  Yes  No  N/A Discussion / justification if SC-2 not implemented:

SC-3 Protect Outdoor Materials Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal
 Yes  No  N/A
Discussion / justification if SC-3 not implemented:

SC-4 Protect Materials Stored in Outdoor Work Areas from Rainfall, Run-On, Runoff, and Wind Dispersal
 Yes  No  N/A
Discussion / justification if SC-4 not implemented:

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X X
X
X
X
Form I-4 Page 2 of 2, Form Date: March 15, 2016
Source Control Requirement Applied?
SC-5 Protect Trash Storage Areas from Rainfall, Run-On, Runoff, and Wind Dispersal
 Yes  No  N/A
Discussion / justification if SC-5 not implemented:

SC-6 Additional BMPs Based on Potential Sources of Runoff Pollutants (must answer for each source listed below)
 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
 Plazas, sidewalks, and parking lots

 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes
 Yes

 No
 No
 No
 No
 No
 No
 No
 No
 No
 No
 No
 No
 No
 No
 No
 No
 No

 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
 N/A
Discussion / justification if SC-6 not implemented. Clearly identify which sources of runoff pollutants are discussed. Justification must be provided for all "No" answers shown above.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
X
X
X
X
X
Site Design BMP Checklist
for All Development Projects
(Standard Projects and Priority Development Projects)
Form I-5
[March 15, 2016]
Project Identification
Project Name – Marcos Specific Plan
Permit Application Number
Site Design BMPs
All development projects must implement site design BMPs SD-1 through SD-8 where applicable and feasible. See Chapter 4 and Appendix E of the Model BMP Design Manual for information to implement site design BMPs shown in this checklist.

Answer each category below pursuant to the following.
 "Yes" means the project will implement the site design BMP as described in Chapter 4 and/or Appendix E of the Model BMP Design Manual. Discussion / justification is not required.  "No" means the BMP is applicable to the project but it is not feasible to implement. Discussion / justification must be provided.
 "N/A" means the BMP is not applicable at the project site because the project does not include the feature that is addressed by the BMP (e.g., the project site has no existing natural areas to conserve).

Discussion / justification may be provided.

Site Design Requirement Applied?
SD-1 Maintain Natural Drainage Pathways and Hydrologic Features  Yes  No  N/A Discussion / justification if SD-1 not implemented:

SD-2 Conserve Natural Areas, Soils, and Vegetation  Yes  No  N/A Discussion / justification if SD-2 not implemented:

Site was previously disturbed.

SD-3 Minimize Impervious Area  Yes  No  N/A
Discussion / justification if SD-3 not implemented:

SD-4 Minimize Soil Compaction  Yes  No  N/A
Discussion / justification if SD-4 not implemented:

SD-5 Impervious Area Dispersion  Yes  No  N/A
Discussion / justification if SD-5 not implemented:

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
X
X
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Form I-5 Page 2 of 2, Form Date: March 15, 2016
Site Design Requirement Applied?
SD-6 Runoff Collection  Yes  No  N/A
Discussion / justification if SD-6 not implemented:

SD-7 Landscaping with Native or Drought Tolerant Species  Yes  No  N/A Discussion / justification if SD-7 not implemented:

SD-8 Harvesting and Using Precipitation  Yes  No  N/A Discussion / justification if SD-8 not implemented:

Harvest and reuse of stormwater is not feasible since irrigation demand will be low following rain events and native/low water use plants will be used.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
Summary of PDP Structural BMPs Form I-6 (PDPs)
[March 15, 2016]
Project Identification
Project Name – Marcos Specific Plan
Permit Application Number
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 local jurisdiction at the completion of construction. This may include requiring the project owner or project owner's representative and engineer of record 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 local jurisdiction 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 (page 3 of this form) 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 or separate.

Based on the geotechnical investigation, percolation rates at the site are very low. Therefore, infiltration BMPs are considered infeasible. Biofiltration BMPs were selected for the majority of the site as the highest performing BMPs that are feasible. Runoff will be collected in gutters, cross gutters, and shallow storm drain, which will direct the runoff to the biofiltration BMPs. The biofiltration BMPs have been sized for both pollutant control and hydromodification mitigation.

In DMA 3, sufficient space for a biofiltration basin is not available due to an existing public sewer line and easement. Here, a proprietary biofiltration unit and underground detention vault will be utilized to satisfy pollutant control and hydromodification requirements.

EPA SWMM was used to model the BMPs for hydromodification mitigation requirements.

The project street frontage on Grand Avenue will be treated utilizing Green Street features. The frontage improvements include addition of a sidewalk and bike path separated from Grand Avenue by a landscaped parkway. The sidewalk and bike path will be sloped to the landscaped parkway which will include street trees where allowed by sight distance constraints. This landscaped parkway and street trees will provide retention and pollutant removal of runoff from the sidewalk and bike path in accordance with Green Street guidance.

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023

Form I-6 Page 2 of X, Form Date: March 15, 2016
(Page reserved for continuation of description of general strategy for structural BMP implementation at the site)
(Continued from page 1)

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
X
X

Form I-6 Page 3 of X (Copy as many as needed) Form Date: March 15, 2016 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No. BMP 1
Construction Plan Sheet No.

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)
 Partial retention by biofiltration with partial retention (PR-1)  Biofiltration (BF-1)
 Biofiltration with Nutrient Sensitive Media Design (BF-2)  Proprietary Biofiltration (BF-3) meeting all requirements of Appendix F  Flow-thru treatment control with prior lawful approval to meet earlier PDP requirements (provide BMP type/description in discussion section below)
 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)
 Flow-thru treatment control with alternative compliance (provide BMP type/description in discussion section below)
 Detention pond or vault for hydromodification management  Other (describe in discussion section below)

Purpose:
 Pollutant control only
 Hydromodification control only
 Combined pollutant control and hydromodification control  Pre-treatment/forebay for another structural BMP
 Other (describe in discussion section below)

Who will certify construction of this BMP?
Provide name and contact information for the
party responsible to sign BMP verification forms if
required by the [City Engineer] (See Section 1.12 of
the BMP Design Manual)
Kenneth T. Kozlik, PE
Fuscoe Engineering, Inc.
6390 Greenwich Drive, Suite 170
San Diego, CA 92122
[email protected]
Who will be the final owner of this BMP?

To-Be-Formed Homeowner’s Association
Who will maintain this BMP into perpetuity?

To-Be-Formed Homeowner’s Association
What is the funding mechanism for maintenance?

Private

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
Form I-6 Page 4 of X (Copy as many as needed) , Form Date: March 15, 2016 Structural BMP ID No. BMP 1
Construction Plan Sheet No.

Discussion (as needed):

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
X
X
Form I-6 Page 5 of X (Copy as many as needed) Form Date: March 15, 2016 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No. BMP 2
Construction Plan Sheet No.

To-Be-Formed Homeowner’s Association
Who will maintain this BMP into perpetuity?

To-Be-Formed Homeowner’s Association
What is the funding mechanism for maintenance?

Private

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
Form I-6 Page 6 of X (Copy as many as needed) , Form Date: March 15, 2016 Structural BMP ID No. BMP 2
Construction Plan Sheet No.

Discussion (as needed):

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
X
X
Form I-6 Page 7 of X (Copy as many as needed) Form Date: March 15, 2016 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No. BMP 3-MWS
Construction Plan Sheet No.

To-Be-Formed Homeowner’s Association
Who will maintain this BMP into perpetuity?

To-Be-Formed Homeowner’s Association
What is the funding mechanism for maintenance?

Private

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
Form I-6 Page 8 of X (Copy as many as needed) , Form Date: March 15, 2016 Structural BMP ID No. BMP 3-MWS
Construction Plan Sheet No.

Discussion (as needed):

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
X
X
Form I-6 Page 9 of X (Copy as many as needed) Form Date: March 15, 2016 Structural BMP Summary Information
(Copy this page as needed to provide information for each individual proposed structural BMP) Structural BMP ID No. BMP 3-DET
Construction Plan Sheet No.

To-Be-Formed Homeowner’s Association
Who will maintain this BMP into perpetuity?

To-Be-Formed Homeowner’s Association
What is the funding mechanism for maintenance?

Private

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
Form I-6 Page 10 of X (Copy as many as needed) , Form Date: March 15, 2016 Structural BMP ID No. BMP 3-DET
Construction Plan Sheet No.

Discussion (as needed):

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
ATTACHMENT 1

BACKUP FOR PDP POLLUTANT CONTROL BMPS

This is the cover sheet for Attachment 1.

Indicate 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.

 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
 Included as Attachment 1b, separate
from DMA Exhibit

Attachment 1c Form I-7, Harvest and Use Feasibility
Screening Checklist (Required unless the
entire project will use infiltration BMPs)

Refer to Appendix B.3-1 of the BMP
Design Manual to complete Form I-7.

 Included
 Not included because the entire
project will use infiltration BMPs

Attachment 1d Form I-8, Categorization of Infiltration
Feasibility Condition (Required unless
the project will use harvest and use
BMPs)

Refer to Appendices C and D of the BMP
Design Manual to complete Form I-8.

 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 and E of the BMP
Design Manual for structural pollutant
control BMP design guidelines

 Included

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
Use this checklist to ensure the required information has been included on the DMA Exhibit:

The DMA Exhibit must identify:

 Underlying hydrologic soil group
 Approximate depth to groundwater
 Existing natural hydrologic features ( watercourses, seeps, springs, wetlands)  Critical coarse sediment yield areas to be protected
 Existing topography and impervious areas
 Existing and proposed site drainage network and connections to drainage offsite  Proposed demolition
 Proposed grading
 Proposed impervious features
 Proposed design features and surface treatments used to minimize imperviousness  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)  Potential pollutant source areas and corresponding required source controls (see Chapter 4, Appendix E.1, and Form I-3B)
 Structural BMPs (identify location, type of BMP, and size/detail)

MWS 8-20
MARCOSDMA EXHIBITJOB NO.DRAWN BY:SHEET1 of 2GNIREEN EIGN6390 Greenwich Dr., Suite 170San Diego, California 92122tel 858.554.1500 fax 858.597.0335www.fuscoe.com LEGEND

DATUM NOTE

MARCOSDMA AND HYDROMODIFICATIONDETAILSJOB NO.DRAWN BY:SHEET2 of 2GNIREEN EIGN6390 Greenwich Dr., Suite 170San Diego, California 92122tel 858.554.1500 fax 858.597.0335www.fuscoe.com BIOFILTRATION/PLANTER DETAIL(BMPS 1 & 2)
PROPRIETARY BIOFILTRATION DETAILMODULAR WETLANDS MWS-L-8-20-VNOT TO SCALE

URBANPOND PRECAST CONCRETESTORMWATER DETENTION MODULEBY BIOCLEANNOT TO SCALE

Toliet User Unit Toliet Water Efficient Total Use per
of Normalization Flushing Urinals Visitor Factor Factor Resident or Employee Residential Resident 18.5 NA NA 0.5 9.3
Dwelling Units 102 units Resident per Unit 3.0 Resident Toliet and Urinal Demand 380 cubic - feet / day 36 hr. Demand 571 cubic - feet DCV 9,814 cubic - feet 36 hr. Demand ≥ DCV No
DCV > 36 hr. Demand > 0.25DCV No
36 hr. Demand < 0.25DCV Yes
Harvest Use: Not Feasible
Harvest and use is considered to be infeasible

General Landscape Type 36-Hour Planning Level Irrigation Demand Units Hydrozone - Moderate Plant Water Use 1,470 gal /acre / 36 hrs Proposed Planted Area 1.47 acres
36 hr. Demand 289 cubic - feet DCV 9,814 cubic - feet 36 hr. Demand ≥ DCV No
DCV > 36 hr. Demand > 0.25DCV No
36 hr. Demand < 0.25DCV Yes
Harvest Use: Not Feasible
Harvest and use is considered to be infeasible

Toliet and Urinal Water Usage per Resident or Employee
Land Use Type Per Capita Use per Day
Planning Level Irrigation Demand by Plant Factor and Landscape Type

Categorization of Infiltration Feasibility Condition Form I-8

Part 1 – Full Infiltration Feasibility Screening Criteria Would infiltration of the full design volume be feasible from a physical perspective without any undesirable consequences that cannot be reasonably mitigated?

Criteria Screening Question Yes No
1 Is the estimated reliable infiltration rate below proposed facility locations greater than 0.5 inches per hour? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D.
☐ ☒
Provide basis:

Infiltration to be verified by testing per city’s BMP Manual Appendix D. Maximum infiltration rate observed was 0.04 in/hr. Testing performed by GeoTek, Inc, in their report Draft Geotechnical Evaluation, Proposed Commercial Development, SWC Grading Avenue and Linda Vista Drive, dated 5/28/2020.

Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. 2 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2. ☐ ☒
Provide basis:

Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability.

3 Can infiltration greater than 0.5 inches per hour be allowed without increasing risk of groundwater contamination (shallow water table, storm water pollutants or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. ☐ ☒
Provide basis:

Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. 4 Can infiltration greater than 0.5 inches per hour be allowed without causing potential water balance issues such as change of seasonality of ephemeral streams or increased discharge of contaminated groundwater to surface waters? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3.
☐ ☒
Provide basis:

Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability.

Part 1
Result*
If all answers to rows 1-4 are “Yes” a full infiltration design is potentially feasible. The feasibility screening category is Full Infiltration.

If any answer from row 1-4 is “No”, infiltration may be possible to some extent but would not generally be feasible or desirable to achieve a “full infiltration” design.

Proceed to Part 2
Full
Infiltration
Feasible
☐
Full
Infiltration
Infeasible
☒
*To be completed using gathered site information and best professional judgement considering the definition of MEP in the MS4 permit. Additional testing and/or studies may be required by Agency/Jurisdictions to substantiate findings.

Categorization of Infiltration Feasibility Condition Form I-8

Part 2 – Partial Infiltration vs. No Infiltration Feasibility Screening Criteria Would infiltration of water in any appreciable amount be physically feasible without any negative consequences that cannot be reasonably mitigated?

Criteria Screening Question Yes No
5 Do soil and geologic conditions allow for infiltration in any appreciable rate or volume? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2 and Appendix D.
☐ ☒
Provide basis:

Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. 6 Can infiltration in any appreciable quantity be allowed without increasing risk of geotechnical hazards (slope stability, groundwater mounding, utilities, or other factors) that cannot be mitigated to an acceptable level? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.2. ☒ ☐
Provide basis:

Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability.

7 Can infiltration in any appreciable quantity be allowed without posing significant risk for groundwater related concerns (shallow water table, storm water pollutants or other factors)? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3.
☒ ☐
Provide basis:

Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability. 8 Can infiltration be allowed without violating downstream water rights? The response to this Screening Question shall be based on a comprehensive evaluation of the factors presented in Appendix C.3. ☒ ☐
Provide basis:

Summarize findings of studies; provide reference to studies, calculations, maps, data sources, etc. Provide narrative discussion of study/data source applicability.

Part 2
Result*
If all answers to rows 1-4 are “Yes” a partial infiltration design is potentially feasible. The feasibility screening category is Partial Infiltration.

If any answer from row 5-8 is “No”, infiltration of any volume is considered to be infeasible within the drainage area. The feasibility screening category is No Infiltration.

Partial
Infiltration
☐
No
Infiltration
☒
*To be completed using gathered site information and best professional judgement considering the definition of MEP in the MS4 permit. Additional testing and/or studies may be required by Agency/Jurisdictions to substantiate findings.

Green Street SWQMP for Marcos October 5, 2022

Page 1 of 2 ends

INTRODUCTION

Project Description:

The Marcos project consists of approximately 10.8 acres near the southwest corner of the Linda Vista Drive and Grand Avenue intersection in the city of San Marcos, California. The project is bisected by a channel which separates the project into two development areas. The 5.0 acres north of the channel will be used to develop 102 condominium residential units while the 5.8 acres south of the channel will be developed for commercial and mixed use.

Existing Conditions:

The existing site consists of two development area that were previously commercial pads but have had the buildings demolished. From an aerial view, both areas visually appear flat. The channel was recently improved by the City of San Marcos (CIP Project Code 88214, “Grand Avenue Drainage / Road Improvements”, IP-4826 and VWD no. 201930). Please reference Appendix 7 in the Drainage Report for channel improvement drawings. Each development area had new storm drain added to collect runoff from the pads and discharge into the improved channel. A bridge was constructed to link the two development areas.

Proposed Conditions :

In the proposed condition, onsite drainage will be covered by a separate SWQMP. Proposed public improvements around the site will be treated by gre en street elements including trees. Ultimately, the proposed development areas will be re-graded to ensure that the runoff is routed to the channel.

Green Street SWQMP for Marcos October 5, 2022

Page 2 of 2 ends

Green Street Elements
Public improvement treatment will be provided by pr ivate green street element trees. Proposed trees would capture storm water, provide shade, and cool pavement.

Water Quality Compliance:

The proposed project would not require Regional Wat er Quality Control Board Section 401 Certification or a U.S. Army Corps of Engineers 404 permit. The project site is fully developed and devoid of natural vegetation and habitat.

Operation/Maintenance:

Green street elements would fall under the responsi bility of would be formed Homeowners Association.
22 Applicability of Storm Water Best Management Practices (BMP) Requirements (Storm Water Intake Form for all Development Permit Applications) For detailed information please visit:
http://www.san‐marcos.net/departments/development‐services/stormwater/development‐planning Form I‐1
Version 1.0
[March 15, 2016]
Project Identification
Project Name:

Description:

Permit Application Number (if applicable): Date:

Project Address:

Determination of Requirements
This form is required as part of the City’s application process. The purpose of this form is to identify potential land development planning storm water requirements that apply to development projects.

To access the BMP Design Manual, Storm Water Quality Management Plan (SWQMP) templates, and other pertinent information related to this program please refer to:
http://www.san‐marcos.net/departments/development‐services/stormwater/development‐planning

Please answer each of the following steps below, starting with Step 1 and progressing through each step until reaching "Stop".

Step Answer Progression
Step 1: Based on the above, Is the project a
"development project"? (see definition above)
See Section 1.3 of the BMP Design Manual for
further guidance if necessary.
Yes Go to Step 2.
No Permanent BMP requirements do not apply. No
SWQMP will be required. Provide brief discussion
below. STOP.

Discussion / justification if the project is not a "development project" (e.g., the project includes only interior remodels within an existing building):

Step 2: Is the project a Standard Project, Priority
Development Project (PDP), or exception to PDP
definitions?

To answer this item, complete Form I‐2, Project
Type Determination. See Section 1.4 of the BMP
Design Manual in its entirety for guidance.

In addition to Section 1.4, please refer to the
City’s SWQMP Submittal Requirements form.

Standard Project Only Standard Project requirements apply, including Standard Project SWQMP.  STOP.
PDP Standard and PDP requirements apply, including
PDP SWQMP.  Go to Step 3 on the following page.
Exception to PDP
definitions
Standard Project requirements apply, and any
additional requirements specific to the type of
project. Provide discussion and list any additional
requirements below. Prepare Standard Project
SWQMP.  STOP.

Discussion / justification, and additional requirements for exceptions to PDP definitions, if applicable:
23 Form I‐1 Page 2
Step 3 (PDPs only). Please answer the list of questions in this section to determine if hydromodification requirements reply to the proposed PDP. Does the project:

Step 3a. Discharge storm water
runoff directly to the Pacific Ocean?
Yes STOP. Hydromodification requirements do not apply. No Continue to Step 3b.

Step 3b. Discharge storm water
runoff directly to an enclosed
embayment, not within protected
areas?
Yes STOP. Hydromodification requirements do not apply. No Continue to Step 3c.

Step 3c. Discharge storm water
runoff directly to a water storage
reservoir or lake, below spillway or
normal operating level?
Yes STOP. Hydromodification requirements do not apply. No Continue to Step 3d.

Step 3d. Discharge storm water
runoff directly to an area identified
in WMAA?
Yes STOP. Hydromodification requirements do not apply. No Hydromodification requirements apply to the project. Go to Step

4. Discussion / justification if hydromodification control requirements do not apply:

Yes Management measures required for protection of critical coarse sediment yield areas (Chapter 6.2).

Stop.
No Management measures not required for protection of critical coarse sediment yield areas.

Provide brief discussion below.

Stop.

GRAND AVENUELINDA VISTA DRIVEMARCOS PROJECTGREEN STREET EXHIBITJOB NO.DRAWN BY:SHEET1 of 1GNIREENEIGN6390 Greenwich Dr., Suite 170San Diego, California 92122tel 858.554.1500 fax 858.597.0335www.fuscoe.com

GREEN STREET CONSTRUCTIONLANDSCAPE AREA WITH STREET TREES PER DETAIL A & BCURB OPENING WITH ENERGY DISSIPATOR PER DETAIL CLEGENDTRIBUTARY AREALIMIT OF GRADING

GREEN STREET EXEMPTION REQUIREMENT

CURB OPENING (LINDA VISTA DR)-C

B- TREE WELL (LINDA VISTA DR)

A- STREET TREE (GRAND AVE)
City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
ATTACHMENT 2

BACKUP FOR PDP HYDROMODIFICATION CONTROL MEASURES

This is the cover sheet for Attachment 2.

 Mark this box if this attachment is empty because the project is exempt from PDP hydromodification management requirements.

Indicate which Items are Included behind this cover sheet:

Attachment
Sequence
Contents Checklist
Attachment 2a Hydromodification Management Exhibit
(Required)

 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.
 Exhibit showing project drainage
boundaries marked on WMAA
Critical Coarse Sediment Yield Area
Map (Required)

Optional analyses for Critical Coarse
Sediment Yield Area Determination
 6.2.1 Verification of Geomorphic
Landscape Units Onsite
 6.2.2 Downstream Systems
Sensitivity to Coarse Sediment
 6.2.3 Optional Additional Analysis of
Potential Critical Coarse Sediment
Yield Areas Onsite

Attachment 2c Geomorphic Assessment of Receiving
Channels (Optional)
See Section 6.3.4 of the BMP Design
Manual.
 Not performed
 Included
 Submitted as separate stand-alone
document

Attachment 2d Flow Control Facility Design, including
Structural BMP Drawdown Calculations
and Overflow Design Summary
(Required)
See Chapter 6 and Appendix G of the
BMP Design Manual
 Included
 Submitted as separate stand-alone
document

Attachment 2e Vector Control Plan (Required when
structural BMPs will not drain in 96
hours)
 Included
 Not required because BMPs will
drain in less than 96 hours

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
Use this checklist to ensure the required information has been included on the Hydromodification Management Exhibit:

The Hydromodification Management Exhibit must identify:

 Underlying hydrologic soil group
 Approximate depth to groundwater
 Existing natural hydrologic features ( watercourses, seeps, springs, wetlands)  Critical coarse sediment yield areas to be protected
 Existing topography
 Existing and proposed site drainage network and connections to drainage offsite  Proposed grading
 Proposed impervious features
 Proposed design features and surface treatments used to minimize imperviousness  Point(s) of Compliance (POC) for Hydromodification Management  Existing and proposed drainage boundary and drainage area to each POC (when necessary, create separate exhibits for pre-development and post-project conditions)  Structural BMPs for hydromodification management (identify location, type of BMP, and size/detail)

GRAND AVE
LINDA VISTA DR.MARCOSHYDROMODIFICATION EXHIBITEXISTING CONDITIONSJOB NO.DRAWN BY:SHEET1 of 1GNIREEN EIGN6390 Greenwich Dr., Suite 170San Diego, California 92122tel 858.554.1500 fax 858.597.0335www.fuscoe.com LEGEND

GRAND AVE
MWS 8-20

GRAND AVE
MARCOS
JOB NO.DRAWN BY:SHEET1 of 1GNIREEN EIGN6390 Greenwich Dr., Suite 170San Diego, California 92122tel 858.554.1500 fax 858.597.0335www.fuscoe.com

DATUM NOTE

HYDROMODIFICATION EXHIBITPROPOSED CONDITIONS
LEGEND

A 0.012 0.15 0.05 0.1 25% 1.5 0.23
B 0.012 0.15 0.05 0.1 25% 3 0.15
C 0.012 0.15 0.05 0.1 25% 6 0.08
D 0.012 0.15 0.05 0.1 25% 9 0.019
Type % SF AC Total (AC)
A 0% - 0.00
B 0% - 0.00
C 88% 74,581 1.71
D 12% 10,243 0.24

1.95 0.0195
*Weighted factor
Type % SF AC Total (AC)
A 0% - 0.00
B 0% - 0.00
C 100% 3,102 0.07
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 1,939 0.04
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 285 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 285 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 1,639 0.04
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 270 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 169 0.00
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 210 0.00
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 270 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 98% 2,298 0.05
D 2% 58 0.00
A 0% - 0.00
B 0% - 0.00
C 91% 2,419 0.06
D 9% 243 0.01
A 0% - 0.00
B 0% - 0.00
C 100% 3,958 0.09
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 2,078 0.05
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 1,173 0.03
WLK K 0.06 BMP 1 5 0.5% 53%
WLK 1J 0.05 BMP 1 15 0.5% 48%
WLK 1I 0.00619 WLK 1K 5 0.5% 0%
Proposed Conditions for DMA 1
Soil Suction
Head*Average Slope Impervious %Subcatchment
ID OutfallArea Width (ft)
RD 1C
WLK 1H 0.00482 BMP 1 3 0.5%
POC E
Conductivity
(Compacted)*
Initial
Deficit*
Existing Conditions
Width (ft)Soil Impervious %Suction
Head*
0% 6.36 0.07 0.31
Soil Conductivity
(Compacted)
D store-
Perv Zero-Imper Suction
HeadN-Imperv N-Perv D store-
Imperv
Total
AreaSubcatchment
ID Average SlopeOutfall
220 1.0%E1 1.95

6.00 0.08 0.31

6.07 0.07 0.31

6.27 0.07 0.31
Conductivity
(Compacted)*
Initial
Deficit*
82% 6.00 0.08 0.31

0.08 0.31

0.5% 100% 6.000.03 RD 1D 20
RD 1A 0.09 BMP 1 26

0.08 0.310.5% 100% 6.00RD 1B 0.05 RD 1D 20

0.5% 42% 6.00WLK 1A 0.07122 RD 1A 20

0.5% 35% 6.00WLK 1B 0.04452 WLK 1K 15

0.5% 83% 6.00WLK 1C 0.00655 RD 1D 3

0.5% 85% 6.00WLK 1D 0.00655 RD 1D 3

0.5% 61% 6.00WLK 1E 0.04 RD 1C 15
WLK 1G 0.00389 RD 1D 3

0.08 0.310.5% 0% 6.00WLK 1F 0.00619 RD 1D 5

0.08 0.310.5% 81% 6.00

0.08 0.310.7% 100% 6.00
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 1,451 0.03
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 2,948 0.07
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 4,330 0.10
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 4,330 0.10
D 0% 0.00
A 0% - 0.00
B 0% - 0.00
C 87% 5,109 0.12
D 13% 777 0.02
A 0% - 0.00
B 0% - 0.00
C 93% 829 0.02
D 7% 61 0.00

0.90 0.0090

0.02 0.92
*Weighted factor
Type % SF AC Total (AC)
A 0% - 0.00
B 0% - 0.00
C 100% 2,278 0.05
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 2,947 0.07
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 373 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 373 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 249 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 95% 1,973 0.05
D 5% 112 0.00
A 0% - 0.00
B 0% - 0.00
C 66% 5,491 0.13
D 34% 2,839 0.07
A 0% - 0.00
B 0% - 0.00
C 100% 3,160 0.07
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 2,000 0.05
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 92% 8,474 0.19
D 8% 737 0.02
A 0% - 0.00
B 0% - 0.00
C 100% 5,886 0.14

0.5% 100% 6.00 0.08 0.31RD 1D 0.03 BMP 1 20
44 21
30 3

6.00 0.08 0.31BLDG A 0.14 RD A 0.5% 100%

6.00 0.08 0.31
RD C 0.21 BMP 26 0.5% 100% 6.24 0.07 0.31
RD B 0.05 RD C 1.0% 100%

7.02 0.06 0.31
RD A 0.07 RD C 20 0.5% 100% 6.00 0.08 0.31
WLK G 0.19 BMP 0.5% 28%

6.00 0.08 0.31
WLK F 0.04785 RD C 5 0.5% 62% 6.16 0.07 0.31
WLK E 0.00571 RD B 0.5% 77%

6.00 0.08 0.31
WLK D 0.00855 RD A 3 0.5% 82% 6.00 0.08 0.31
WLK C 0.00856 RD A 3 0.5% 82%

6.00 0.08 0.31
WLK B 0.06766 RD B 15 0.5% 52% 6.00 0.08 0.31
WLK A 0.05229 RD A 20 0.5% 40%
Proposed Conditions for DMA 2
Subcatchment
ID
Soil Area Outfall Width (ft) Average Slope Impervious %Suction Head*
Conductivity
(Compacted)*
Initial
Deficit*
Total BMP
Total w/ BMP
Total w/o BMP

0.08 0.31BLDG 1A 0.07 RD 1A 22 0.5% 100% 6.00

0.08 0.310.5% 100% 6.00BLDG 1B 0.10 RD 1B 42

0.08 0.310.5% 100% 6.00BLDG 1C 0.10 RD 1B 42

0.5% 100% 6.40BLDG 1D 0.14 RD 1D 42

6.21 0.07 0.31

0.07 0.31
BMP 1 0.02043 POC E 5 0.5% 0%
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 2,923 0.07
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 5,886 0.14
D 0% 0.00
A 0% - 0.00
B 0% - 0.00
C 74% 6,345 0.15
D 26% 2,273 0.05
A 0% - 0.00
B 0% - 0.00
C 42% 544 0.01
D 58% 763 0.02

1.25 0.0125

0.03 1.28
*Weighted factor
Outflow Threshold 0.0220
BMP 0.03001 POC E 0.5% 0%

6.00 0.08 0.31

6.79 0.06 0.31

7.75 Total w/o BMP
Total BMP
Total w/ BMP
12 BLDG C 0.14 RD C 44

0.04 0.30
BLDG D 0.20 RD C 44 0.5% 100%

0.5% 100%
BLDG B 0.07 RD A 22 0.5% 100% 6.00 0.08 0.31
Water Quality
HydroMod
sf ft in ft sf cfs cf hr in/hr cfs in ft offset (ft)
1 930 1.00 1 0.083 0.005450.018560362799.3 41.89 0.1654 0.0455 1 0.083 0.50 2 1300 1.00 1 0.083 0.005450.01856036 3913 58.56 0.1183 0.0455 1 0.083 0.50 Riser Orifice, d
Volume of
Stored
Water, V
Time Req'd to
Drain Stored
Water, T
Drain
Coefficient, C
Average
Discharge
Rate, Qavg
Divider Cutoff
Flow
Depth of
Stored
Water, D
Diameter of Orifice, dAreaBMP
Area of
Orifice, Ao

HYDROMODIFICATION MODELING RESEARCH PROJECT

ARTIST VILLAGE POC E

THIS POC PASSES
Record Period = 45 Years = 16425 days = 394200 hours Time Steps >= 110% 0 % time Flow Exceeded = 100*m/(394200+1) Time Steps >= 100% 0 Max % = 98%
Rank (m)
Return
Interval
(yrs)
% Time Flow
Exceeded
Exist. Cond. Prop. Cond.Prop. w/BMP Exist. Cond.Prop. Cond.Prop. w/BMPPercentagePASS/FAIL 1 45.00 0.869 1.166 0.0003 0.87 1.16 134% FAIL 2 22.50 0.850 1.026 0.0005 0.85 1.07 121% FAIL 3 15.00 0.757 0.754 0.0008 0.76 1.02 100% PASS 4 11.25 0.751 0.735 0.0010 0.75 0.96 98% PASS 5 9.00 0.707 0.676 0.0013 0.71 0.82 96% PASS 6 7.50 0.650 0.616 0.0015 0.7 0.8 95% PASS 7 6.43 0.644 0.564 0.0018 0.68 0.74 88% PASS 8 5.63 0.589 0.544 0.0020 0.67 0.72 92% PASS 9 5.00 0.586 0.509 0.0023 0.65 0.67 87% PASS 10 4.50 0.585 0.5 0.0025 0.64 0.61 85% PASS 11 4.09 0.558 0.464 0.0028 0.63 0.59 83% PASS 12 3.75 0.537 0.447 0.0030 0.61 0.57 83% PASS 13 3.46 0.521 0.438 0.0033 0.6 0.56 84% PASS 14 3.21 0.516 0.427 0.0036 0.59 0.51 83% PASS 15 3.00 0.509 0.412 0.0038 0.59 0.51 81% PASS 16 2.81 0.498 0.41 0.0041 0.59 0.5 82% PASS 17 2.65 0.462 0.39 0.0043 0.56 0.5 84% PASS 18 2.50 0.399 0.381 0.0046 0.56 0.47 95% PASS 19 2.37 0.394 0.379 0.0048 0.54 0.47 96% PASS 20 2.25 0.393 0.351 0.0051 0.52 0.45 89% PASS 21 2.14 0.390 0.347 0.0053 0.52 0.44 89% PASS 22 2.05 0.389 0.326 0.0056 0.51 0.43 84% PASS 23 1.96 0.372 0.307 0.0058 0.5 0.43 83% PASS 24 1.88 0.370 0.272 0.0061 0.46 0.43 74% PASS 25 1.80 0.360 0.267 0.0063 0.42 0.41 74% PASS 26 1.73 0.345 0.266 0.0066 0.41 0.41 77% PASS 27 1.67 0.344 0.258 0.0068 0.4 0.4 75% PASS 28 1.61 0.316 0.257 0.0071 0.4 0.4 81% PASS 29 1.55 0.313 0.255 0.0074 0.39 0.4 81% PASS 30 1.50 0.309 0.254 0.0076 0.39 0.4 82% PASS 31 1.36 0.287 0.24 0.0079 0.39 0.4 84% PASS 32 1.36 0.287 0.222 0.0081 0.39 0.39 77% PASS 33 1.36 0.287 0.188 0.0084 0.38 0.39 66% PASS 34 1.32 0.282 0.184 0.0086 0.38 0.38 65% PASS 35 1.29 0.280 0.159 0.0089 0.37 0.37 57% PASS 36 1.25 0.268 0.156 0.0091 0.37 0.37 58% PASS 37 1.22 0.265 0.155 0.0094 0.37 0.36 58% PASS 38 1.18 0.263 0.147 0.0096 0.36 0.35 56% PASS 39 1.15 0.234 0.144 0.0099 0.36 0.35 62% PASS 40 1.13 0.231 0.143 0.0101 0.35 0.34 62% PASS 41 1.10 0.225 0.141 0.0104 0.35 0.34 63% PASS 42 1.07 0.223 0.138 0.0107 0.34 0.32 62% PASS 43 1.05 0.215 0.125 0.0109 0.34 0.32 58% PASS 44 1.02 0.212 0.111 0.0112 0.34 0.31 52% PASS 45 1.00 0.209 0.108 0.0114 0.34 0.31 52% PASS 46 0.98 0.204 0.1 0.0117 0.33 0.3 49% PASS 47 0.96 0.187 0.1 0.0119 0.32 0.3 53% PASS 48 0.94 0.186 0.093 0.0122 0.31 0.3 50% PASS 49 0.92 0.182 0.091 0.0124 0.31 0.28 50% PASS 50 0.90 0.174 0.089 0.0127 0.31 0.28 51% PASS 51 0.88 0.172 0.088 0.0129 0.31 0.27 51% PASS 52 0.87 0.170 0.088 0.0132 0.31 0.27 52% PASS 53 0.85 0.169 0.087 0.0134 0.29 0.27 51% PASS 54 0.83 0.163 0.087 0.0137 0.29 0.27 53% PASS 55 0.82 0.162 0.087 0.0140 0.29 0.26 54% PASS 56 0.80 0.159 0.086 0.0142 0.29 0.26 54% PASS Peak Flow (cfs) Hourly Flow Data (cfs) (Duration Calc)

HYDROMODIFICATION MODELING RESEARCH PROJECT

ARTIST VILLAGE POC E

THIS POC PASSES
Record Period = 45 Years = 16425 days = 394200 hours Time Steps >= 110% 0 % time Flow Exceeded = 100*m/(394200+1) Time Steps >= 100% 0 Max % = 98%
Rank (m)
Return
Interval
(yrs)
% Time Flow
Exceeded
Exist. Cond. Prop. Cond.Prop. w/BMP Exist. Cond.Prop. Cond.Prop. w/BMPPercentagePASS/FAIL Peak Flow (cfs) Hourly Flow Data (cfs) (Duration Calc)
57 0.79 0.158 0.084 0.0145 0.29 0.26 53% PASS 58 0.78 0.157 0.084 0.0147 0.29 0.25 54% PASS 59 0.75 0.155 0.083 0.0150 0.28 0.25 54% PASS 60 0.75 0.155 0.082 0.0152 0.28 0.25 53% PASS 61 0.74 0.151 0.081 0.0155 0.28 0.25 54% PASS 62 0.73 0.150 0.081 0.0157 0.27 0.24 54% PASS 63 0.71 0.149 0.079 0.0160 0.27 0.24 53% PASS 64 0.70 0.144 0.078 0.0162 0.27 0.24 54% PASS 65 0.69 0.142 0.078 0.0165 0.27 0.24 55% PASS 66 0.68 0.134 0.077 0.0167 0.27 0.24 57% PASS 67 0.67 0.130 0.077 0.0170 0.26 0.23 59% PASS 68 0.66 0.128 0.075 0.0173 0.26 0.23 59% PASS 69 0.65 0.127 0.074 0.0175 0.25 0.23 58% PASS 70 0.64 0.125 0.074 0.0178 0.24 0.23 59% PASS 71 0.63 0.125 0.074 0.0180 0.24 0.22 59% PASS 72 0.63 0.120 0.072 0.0183 0.23 0.22 60% PASS 73 0.62 0.118 0.072 0.0185 0.23 0.22 61% PASS 74 0.61 0.115 0.072 0.0188 0.23 0.22 63% PASS 75 0.60 0.113 0.072 0.0190 0.22 0.21 64% PASS 76 0.59 0.112 0.071 0.0193 0.22 0.21 63% PASS 77 0.58 0.107 0.071 0.0195 0.21 0.21 66% PASS 78 0.58 0.106 0.071 0.0198 0.21 0.21 67% PASS 79 0.57 0.098 0.069 0.0200 0.21 0.2 70% PASS 80 0.56 0.090 0.069 0.0203 0.21 0.2 77% PASS 81 0.54 0.089 0.069 0.0205 0.21 0.2 78% PASS 82 0.54 0.089 0.068 0.0208 0.21 0.19 76% PASS 83 0.54 0.089 0.068 0.0211 0.2 0.19 76% PASS 84 0.54 0.089 0.067 0.0213 0.2 0.19 75% PASS 85 0.53 0.088 0.066 0.0216 0.19 0.19 75% PASS 86 0.52 0.088 0.066 0.0218 0.19 0.19 75% PASS 87 0.52 0.087 0.066 0.0221 0.19 0.19 76% PASS 88 0.51 0.087 0.066 0.0223 0.19 0.19 76% PASS 89 0.51 0.084 0.065 0.0226 0.19 0.19 77% PASS 90 0.50 0.081 0.065 0.0228 0.19 0.19 80% PASS 91 0.49 0.079 0.065 0.0231 0.19 0.18 82% PASS 92 0.49 0.076 0.062 0.0233 0.18 0.18 82% PASS 93 0.48 0.073 0.062 0.0236 0.18 0.18 85% PASS 94 0.48 0.072 0.061 0.0238 0.18 0.18 85% PASS 95 0.47 0.069 0.059 0.0241 0.17 0.18 86% PASS 96 0.47 0.069 0.059 0.0244 0.17 0.18 86% PASS 97 0.46 0.069 0.059 0.0246 0.17 0.18 86% PASS 98 0.46 0.067 0.058 0.0249 0.17 0.18 87% PASS 99 0.45 0.065 0.057 0.0251 0.17 0.17 88% PASS 100 0.45 0.065 0.057 0.0254 0.17 0.17 88% PASS 101 0.45 0.064 0.057 0.0256 0.17 0.17 89% PASS 102 0.44 0.064 0.056 0.0259 0.17 0.17 88% PASS 103 0.44 0.063 0.056 0.0261 0.17 0.17 89% PASS 104 0.43 0.062 0.055 0.0264 0.16 0.17 89% PASS 105 0.43 0.062 0.055 0.0266 0.16 0.17 89% PASS 106 0.42 0.060 0.055 0.0269 0.16 0.17 92% PASS 107 0.42 0.056 0.055 0.0271 0.16 0.17 98% PASS 108 0.42 0.056 0.055 0.0274 0.16 0.17 98% PASS 109 0.41 0.055 0.054 0.0277 0.16 0.17 98% PASS 110 0.41 0.054 0.054 0.0279 0.16 0.16 100% PASS 111 0.41 0.053 0.054 0.0282 0.15 0.16 102% PASS 112 0.40 0.051 0.053 0.0284 0.15 0.16 104% PASS

0.00.51.00.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0.040 0.045Flow (cfs)% of Time Flow is Exceeded POC E Flow Duration Curve
ExistingProposedMitigated
A 0.012 0.15 0.05 0.1 25% 1.5 0.3 0.23 0.33 no
B 0.012 0.15 0.05 0.1 25% 3 0.2 0.15 0.32 no
C 0.012 0.15 0.05 0.1 25% 6 0.1 0.08 0.31 no
D 0.012 0.15 0.05 0.1 25% 9 0.025 0.019 0.30 no
Type % SF AC Total (AC) Max Min
A 0% - 0.00
B 0% - 0.00
C 67% 40,449 0.93
D 33% 19,513 0.45
A 0% - 0.00
B 0% - 0.00
C 100% 7,728 0.18
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 60,276 1.38
D 0% - 0.00

2.94 *Weighted factor
Type % SF AC Total (AC)
A 0% - 0.00
B 0% - 0.00
C 100% 5,886 0.14
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 5,886 0.14
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 5,886 0.14
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 5,886 0.14
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 3,659 0.08
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 5,886 0.14
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 77% 4,529 0.10
D 23% 1,357 0.03
A 0% - 0.00
B 0% - 0.00
C 4% 304 0.01
D 96% 6,541 0.15
A 0% - 0.00
B 0% - 0.00
C 100% 901 0.02
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 2,832 0.07
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 2,337 0.05
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 5,744 0.13
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 3,243 0.07
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 4,158 0.10
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 2,963 0.07
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 38% 1,213 0.03
D 62% 2,014 0.05
A 0% - 0.00
B 0% - 0.00
C 78% 4,030 0.09
D 22% 1,167 0.03
A 0% - 0.00
B 0% - 0.00
C 100% 4,274 0.10
D 0% - 0.00
100% 6.00 0.08 0.31BF3 RF2 0.13513 45 0.5%
100% 6.00 0.08 0.31
BF2 RF2 0.13513 45 0.5% 100% 6.00 0.08 0.31
BF1 RF3 0.13513 45 0.5%
47% 6.00 0.08 0.31WF1 RF1 0.09812 20 0.5%
100% 6.67 0.06 0.31
RF6 RF4 0.09546 24 0.5% 100% 6.00 0.08 0.31
RF9 MWS 0.11930 24 1.0%
100% 6.00 0.08 0.31
RF8 MWS 0.07408 20 0.5% 100% 7.87 0.04 0.30
RF7 MWS 0.06802 24 0.7%
100% 6.00 0.08 0.31
RF5 RF4 0.07444 20 0.5% 100% 6.00 0.08 0.31
RF4 RF7 0.13186 24 0.9%
100% 6.00 0.08 0.31
RF3 RF4 0.05366 24 0.7% 100% 6.00 0.08 0.31
RF2 RF3 0.06501 20 0.5%
100% 8.87 0.02 0.30
RF1 RF3 0.02068 24 1.0% 100% 6.00 0.08 0.31
BF8 RF8 0.15713 35 0.5%
100% 6.00 0.08 0.31
BF7 RF8 0.13513 45 0.5% 100% 6.69 0.06 0.31
BF6 RF6 0.13513 45 0.5%
100% 6.00 0.08 0.31
BF5 RF5 0.08400 45 0.5% 100% 6.00 0.08 0.31
BF4 RF5 0.13513 45 0.5%
Subcatchment
ID Width (ft) Average Slope
Conductivity
(Compacted)*
Initial
Deficit*
Existing Conditions
Elevations Conductivity
(Existing)*
Max Length
(ft) Width (ft)Soil Impervious
%
Suction
Head*
Total
AreaSubcatchment
ID Average SlopeOutfall
340 176 542.50 537.33 1.5%F1 (South) 1.38
F2 (West) 542.03 539.36 1.9%
Soil Conductivity
(Compacted) GroundwaterD store-
Perv Zero-Imper Suction
Head
Conductivity
(Existing) Initial DeficitN-Imperv N-Perv D store-
Imperv

0.18 0% 6.98 0.08 0.06 0.31POC F
POC F 142 54
Proposed Conditions F
Outfall Soil Area Impervious
% Suction Head*
0% 6.00
Conductivity
(Compacted)*
Initial
Deficit*

0.10 0.08 0.31
F3 (North) 1.38 POC F 440 137 0.10 0.08 0.31 542.71 538.00 1.1% 0% 6.00 A 0% - 0.00
B 0% - 0.00
C 100% 964 0.02
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 378 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 366 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 379 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 336 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 377 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 454 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 2,087 0.05
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 636 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 366 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 378 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 243 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 3,487 0.08
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 571 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 1,200 0.03
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 378 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 330 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 1,907 0.04
D 0% 1 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 356 0.01
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 43% 163 0.00
D 57% 215 0.00
A 0% - 0.00
B 0% - 0.00
C 48% 656 0.02
D 52% 697 0.02
A 0% - 0.00
B 0% - 0.00
C 24% 119 0.00
D 76% 366 0.01
A 0% - 0.00
B 0% - 0.00
C 2% 175 0.00
D 98% 11,358 0.26
A 0% - 0.00
B 0% - 0.00
C 100% 4,845 0.11
D 0% - 0.00
A 0% - 0.00
B 0% - 0.00
C 100% 87 0.00
D 0% - 0.00
81% 6.00 0.08 0.31
WF4 RF1 0.00840 8 0.5% 22% 6.00 0.08 0.31
WF3 RF2 0.00868 3 0.5%
WF2 RF2 0.02214 10 0.5% 4% 6.00 0.08 0.31
71% 6.00 0.08 0.31
WF16 RF4 0.02754 8 0.5% 19% 6.00 0.08 0.31
WF15 RF4 0.01310 8 0.5%

6.00 0.08 0.31
WF14 RF6 0.08006 10 0.5% 46% 6.00 0.08 0.31
RF5 0.00557 3 0.5% 82%

0.08 0.31
WF12 RF5 0.00868 3 0.5% 80% 6.00 0.08 0.31

0.00840 6 0.5% 25% 6.00

0.08 0.31
WF10 RF5 0.01460 10 0.5% 0% 6.00 0.08 0.31

0.04790 10 0.5% 46% 6.00

0.5% 0% 6.00

0.00869 3 0.5% 82% 6.00

0.01041 10 0.5% 13% 6.00

0.00867 3 0.5% 81% 6.00
WF5 RF2
WF6 RF3
WF7 RF3
WF8 WF9
WF9 RF3
WF11 RF4
WF13
0% 6.00 0.08 0.31WF26 RF9 0.00200 5 0.5%
19% 8.95 0.02 0.30
WF25 MWS 0.11122 45 0.5% 61% 6.00 0.08 0.31
WF24 MWS 0.26475 40 0.5%
8% 7.55 0.05 0.30
WF23 RF8 0.01112 3 0.5% 83% 8.27 0.03 0.30
WF22 RF8 0.03105 10 0.5%
0% 6.00 0.08 0.31
WF21 RF8 0.00867 3 0.5% 82% 7.70 0.04 0.30
WF20 RF7 0.00817 6 0.5%
64% 6.00 0.08 0.31
WF19 RF7 0.04382 10 0.5% 48% 6.00 0.07 0.31
WF18 RF4 0.00757 6 0.5%
WF17

0.00771 8

0.00868 3 0.5%RF6 81% 6.00 0.08 0.31

0.08 0.31

0.08 0.31
A 0% - 0.00
B 0% - 0.00
C 29% 82 0.00
D 71% 204 0.00

2.64 0.0264
*Weighted factor
Total
WF27 RF9 0.00658 10 0.5% 78% 8.14 0.03 0.30
ea ft sf ft in ft sf cfs cf hr in ft offset (ft)
3 29 4 1740 3.50 2.5 0.208 0.034070.2170203 4263 5.46 12.00 1.00 2.00 Riser OrificeBMP
Volume of
Stored
Water, V
Time Req'd to
Drain Stored
Water, T
Area of
Orifice, Ao
Average
Discharge
Rate, Qavg
# Units Max Height
per Unit
Depth of
Stored
Water, D
Diameter of Orifice, dArea

0.00.20.40.60.81.01.21.41.61.82.00.000 0.005 0.010 0.015 0.020 0.025 0.030 0.035 0.040 0.045Flow (cfs)% of Time Flow is Exceeded POC F Flow Duration Curve
ExistingProposedMitigated

HYDROMODIFICATION MODELING RESEARCH PROJECT

ARTIST VILLAGE POC F

THIS POC PASSES
Record Period = 45 Years = 16,425 days = 394,200 hours Time Steps > 110% 0 % time Flow Exceeded = 100*m/(394200+1) Time Steps = 110% 0 Max % = 81%
Rank (m)
Return
Interval
(yrs)
% Time Flow
Exceeded
Exist. Cond. Prop. Cond.Prop. w/BMP Exist. Cond.Prop. Cond.Prop. w/BMPPercentagePASS/FAIL 1 45.00 1.521 2.158 1.505 0.0003 1.52 1.51 99% PASS 2 22.50 1.412 1.982 1.501 0.0005 1.41 1.5 106% PASS 3 15.00 1.224 1.944 1.009 0.0008 1.22 1.42 82% PASS 4 11.25 1.218 1.920 0.937 0.0010 1.22 1.36 77% PASS 5 9.00 1.179 1.798 0.892 0.0013 1.18 1.27 76% PASS 6 7.50 1.005 1.760 0.775 0.0015 1.13 1.14 77% PASS 7 6.43 0.939 1.680 0.765 0.0018 1.11 1.01 81% PASS 8 5.63 0.918 1.677 0.723 0.0020 1.01 0.95 79% PASS 9 5.00 0.891 1.610 0.486 0.0023 1 0.95 55% PASS 10 4.50 0.884 1.572 0.364 0.0025 0.98 0.94 41% PASS 11 4.09 0.853 1.537 0.341 0.0028 0.96 0.89 40% PASS 12 3.75 0.794 1.536 0.304 0.0030 0.94 0.89 38% PASS 13 3.46 0.788 1.529 0.294 0.0033 0.94 0.85 37% PASS 14 3.21 0.693 1.520 0.218 0.0036 0.92 0.78 31% PASS 15 3.00 0.685 1.456 0.217 0.0038 0.89 0.78 32% PASS 16 2.81 0.670 1.442 0.216 0.0041 0.88 0.77 32% PASS 17 2.50 0.669 1.425 0.214 0.0043 0.85 0.76 32% PASS 18 2.50 0.644 1.417 0.213 0.0046 0.79 0.75 33% PASS 19 2.37 0.627 1.386 0.211 0.0048 0.79 0.74 34% PASS 20 2.25 0.614 1.281 0.209 0.0051 0.7 0.72 34% PASS 21 2.14 0.587 1.274 0.209 0.0053 0.69 0.71 36% PASS 22 2.05 0.580 1.271 0.204 0.0056 0.69 0.69 35% PASS 23 1.96 0.543 1.261 0.202 0.0058 0.68 0.67 37% PASS 24 1.80 0.543 1.260 0.2 0.0061 0.67 0.62 37% PASS 25 1.80 0.539 1.244 0.196 0.0063 0.67 0.62 36% PASS 26 1.73 0.526 1.216 0.194 0.0066 0.67 0.6 37% PASS 27 1.67 0.524 1.199 0.189 0.0068 0.64 0.58 36% PASS 28 1.61 0.518 1.191 0.187 0.0071 0.64 0.58 36% PASS 29 1.55 0.497 1.185 0.186 0.0074 0.63 0.58 37% PASS 30 1.50 0.481 1.162 0.186 0.0076 0.62 0.57 39% PASS 31 1.45 0.476 1.162 0.185 0.0079 0.62 0.54 39% PASS 32 1.41 0.438 1.159 0.185 0.0081 0.61 0.54 42% PASS 33 1.36 0.424 1.157 0.184 0.0084 0.61 0.54 43% PASS 34 1.32 0.409 1.107 0.184 0.0086 0.59 0.52 45% PASS 35 1.29 0.393 1.090 0.183 0.0089 0.58 0.49 47% PASS 36 1.25 0.371 1.084 0.182 0.0091 0.57 0.49 49% PASS 37 1.22 0.340 1.048 0.177 0.0094 0.57 0.49 52% PASS 38 1.18 0.300 1.045 0.176 0.0096 0.54 0.48 59% PASS 39 1.15 0.300 1.027 0.176 0.0099 0.54 0.47 59% PASS 40 1.13 0.299 0.990 0.172 0.0101 0.54 0.45 58% PASS 41 1.07 0.293 0.982 0.17 0.0104 0.54 0.44 58% PASS 42 1.07 0.292 0.975 0.169 0.0107 0.53 0.44 58% PASS 43 1.05 0.275 0.967 0.169 0.0109 0.53 0.43 61% PASS 44 1.02 0.254 0.966 0.169 0.0112 0.52 0.43 67% PASS 45 1.00 0.254 0.960 0.168 0.0114 0.52 0.42 66% PASS 46 0.98 0.228 0.954 0.167 0.0117 0.51 0.41 73% PASS 47 0.96 0.223 0.933 0.166 0.0119 0.51 0.37 74% PASS 48 0.94 0.213 0.930 0.166 0.0122 0.5 0.37 78% PASS 49 0.92 0.208 0.915 0.165 0.0124 0.5 0.37 79% PASS 50 0.90 0.206 0.909 0.165 0.0127 0.48 0.37 80% PASS 51 0.88 0.190 0.907 0.162 0.0129 0.48 0.36 85% PASS 52 0.87 0.179 0.907 0.162 0.0132 0.47 0.36 91% PASS 53 0.85 0.179 0.901 0.162 0.0134 0.44 0.36 91% PASS 54 0.83 0.179 0.900 0.162 0.0137 0.42 0.36 91% PASS 55 0.82 0.178 0.889 0.161 0.0140 0.42 0.35 90% PASS 56 0.79 0.177 0.888 0.161 0.0142 0.42 0.35 91% PASS Peak Flow (cfs) Hourly Flow Data (cfs) (Duration Calc)

HYDROMODIFICATION MODELING RESEARCH PROJECT

ARTIST VILLAGE POC F

THIS POC PASSES
Record Period = 45 Years = 16,425 days = 394,200 hours Time Steps > 110% 0 % time Flow Exceeded = 100*m/(394200+1) Time Steps = 110% 0 Max % = 81%
Rank (m)
Return
Interval
(yrs)
% Time Flow
Exceeded
Exist. Cond. Prop. Cond.Prop. w/BMP Exist. Cond.Prop. Cond.Prop. w/BMPPercentagePASS/FAIL Peak Flow (cfs) Hourly Flow Data (cfs) (Duration Calc)
57 0.79 0.171 0.888 0.16 0.0145 0.42 0.34 94% PASS 58 0.78 0.171 0.867 0.159 0.0147 0.41 0.34 93% PASS 59 0.76 0.162 0.867 0.159 0.0150 0.41 0.33 98% PASS 60 0.75 0.159 0.860 0.159 0.0152 0.4 0.32 100% PASS 61 0.74 0.158 0.854 0.158 0.0155 0.39 0.32 100% PASS 62 0.73 0.148 0.851 0.156 0.0157 0.38 0.32 105% PASS 63 0.71 0.139 0.847 0.156 0.0160 0.37 0.32 112% FAIL 64 0.70 0.139 0.840 0.155 0.0162 0.37 0.31 112% FAIL 65 0.69 0.135 0.830 0.154 0.0165 0.36 0.3 114% FAIL 66 0.68 0.134 0.826 0.154 0.0167 0.36 0.3 115% FAIL 67 0.67 0.129 0.824 0.154 0.0170 0.34 0.3 119% FAIL 68 0.66 0.128 0.814 0.154 0.0173 0.33 0.3 120% FAIL 69 0.65 0.127 0.812 0.153 0.0175 0.3 0.3 120% FAIL 70 0.64 0.124 0.811 0.153 0.0178 0.3 0.3 123% FAIL 71 0.63 0.123 0.802 0.153 0.0180 0.3 0.3 124% FAIL 72 0.63 0.120 0.798 0.153 0.0183 0.3 0.29 128% FAIL 73 0.62 0.117 0.798 0.153 0.0185 0.29 0.29 131% FAIL 74 0.61 0.112 0.793 0.152 0.0188 0.29 0.28 136% FAIL 75 0.57 0.105 0.793 0.151 0.0190 0.29 0.28 144% FAIL 76 0.57 0.105 0.787 0.151 0.0193 0.29 0.28 144% FAIL 77 0.57 0.105 0.787 0.15 0.0195 0.28 0.28 143% FAIL 78 0.57 0.105 0.779 0.15 0.0198 0.28 0.28 143% FAIL 79 0.57 0.104 0.744 0.149 0.0200 0.28 0.28 143% FAIL 80 0.56 0.102 0.743 0.148 0.0203 0.28 0.27 145% FAIL 81 0.56 0.100 0.741 0.148 0.0205 0.27 0.27 148% FAIL 82 0.55 0.099 0.735 0.147 0.0208 0.27 0.27 148% FAIL 83 0.54 0.096 0.731 0.147 0.0211 0.27 0.26 153% FAIL 84 0.54 0.096 0.720 0.146 0.0213 0.27 0.25 152% FAIL 85 0.53 0.090 0.720 0.146 0.0216 0.27 0.25 162% FAIL 86 0.52 0.088 0.716 0.146 0.0218 0.26 0.24 166% FAIL 87 0.52 0.088 0.714 0.146 0.0221 0.25 0.24 166% FAIL 88 0.51 0.085 0.714 0.145 0.0223 0.25 0.23 171% FAIL 89 0.51 0.076 0.713 0.145 0.0226 0.25 0.23 191% FAIL 90 0.50 0.069 0.712 0.145 0.0228 0.24 0.23 210% FAIL 91 0.49 0.069 0.710 0.145 0.0231 0.24 0.22 210% FAIL 92 0.49 0.063 0.708 0.144 0.0233 0.24 0.22 229% FAIL 93 0.48 0.062 0.701 0.144 0.0236 0.23 0.22 232% FAIL 94 0.48 0.060 0.697 0.143 0.0238 0.23 0.22 238% FAIL 95 0.47 0.057 0.697 0.142 0.0241 0.22 0.22 249% FAIL 96 0.47 0.057 0.696 0.141 0.0244 0.22 0.22 247% FAIL 97 0.46 0.055 0.696 0.141 0.0246 0.21 0.22 256% FAIL 98 0.46 0.054 0.693 0.14 0.0249 0.21 0.22 259% FAIL 99 0.45 0.043 0.689 0.14 0.0251 0.21 0.22 326% FAIL 100 0.45 0.043 0.680 0.14 0.0254 0.21 0.22 326% FAIL 101 0.45 0.043 0.675 0.14 0.0256 0.21 0.22 326% FAIL 102 0.42 0.043 0.673 0.137 0.0259 0.2 0.22 319% FAIL 103 0.42 0.043 0.665 0.137 0.0261 0.19 0.22 319% FAIL 104 0.42 0.043 0.660 0.136 0.0264 0.19 0.22 316% FAIL 105 0.42 0.043 0.655 0.136 0.0266 0.19 0.22 316% FAIL 106 0.42 0.039 0.653 0.135 0.0269 0.19 0.22 346% FAIL 107 0.42 0.039 0.652 0.135 0.0271 0.19 0.22 346% FAIL 108 0.42 0.038 0.652 0.134 0.0274 0.18 0.22 353% FAIL 109 0.41 0.037 0.649 0.134 0.0277 0.18 0.22 362% FAIL 110 0.41 0.037 0.646 0.133 0.0279 0.18 0.22 359% FAIL 111 0.41 0.034 0.641 0.133 0.0282 0.18 0.22 391% FAIL 112 0.40 0.034 0.640 0.133 0.0284 0.18 0.22 391% FAIL City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
ATTACHMENT 3
Structural BMP Maintenance Information

This is the cover sheet for Attachment 3.

Indicate which Items are Included behind this cover sheet:

Attachment
Sequence
Contents Checklist
Attachment 3a Structural BMP Maintenance Thresholds
and Actions (Required)

 Included

See Structural BMP Maintenance
Information Checklist on the back of
this Attachment cover sheet.

Attachment 3b Draft Maintenance Agreement (when
applicable)
 Included
 Not Applicable

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
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 3a must identify:

 Typical maintenance indicators and actions for proposed structural BMP(s) based on Section 7.7 of the BMP Design Manual

Attachment 3b is not required for preliminary design / planning / CEQA level submittal.

 Final Design level submittal:

Attachment 3a must identify:

 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
 Maintenance thresholds specific to the structural BMP(s), with a location-specific frame of reference (e.g., level of accumulated materials that triggers removal of the materials, to be identified based on viewing marks on silt posts or measured with a survey rod with respect to a fixed benchmark within the BMP)
 Recommended equipment to perform maintenance
 When applicable, necessary special training or certification requirements for inspection and maintenance personnel such as confined space entry or hazardous waste management

Attachment 3b: For private entity operation and maintenance, Attachment 3b shall include a draft maintenance agreement in the local jurisdiction's standard format (PDP applicant to contact the [City Engineer] to obtain the current maintenance agreement forms).

BF-1 Biofiltration

E-120 January 2018
E.18 BF-1 Biofiltration

Location: 43rd Street and Logan Avenue, San Diego, California Description
Biofiltration (Bioretention with underdrain) facilities are vegetated surface water systems that filter water through vegetation, and soil or engineered media prior to discharge via underdrain or overflow to the downstream conveyance system. Bioretention w ith underdrain facilities are commonly incorporated into the site within parking lot landscaping, along roadsides, and in open spaces. Because these types of facilities have limited or no infiltration, they are typically designed to provide enough hydraulic head to move flows through the underdrain connection to the storm drain system. Treatment is achieved through filtration, sedimentation, sorption, biochemical processes and plant uptake.

Typical bioretention with underdrain components include:
• Inflow distribution mechanisms (e.g, perimeter flow spreader or filter strips) • Energy dissipation mechanism for concentrated inflows (e.g., splash blocks or riprap) • Shallow surface ponding for captured flows
• Side slope and basin bottom vegetation selected based on expected climate and ponding depth
• Non-floating mulch layer (Optional)
• Media layer (planting mix or engineered media) capable of supporting vegetation growth • Filter course layer consisting of aggregate to prevent the migration of fines into uncompacted native soils or the aggregate storage layer • Aggregate storage layer with underdrain(s)
MS4 Permit Category
Biofiltration

Manual Category
Biofiltration

Applicable Performance
Standard
Pollutant Control
Flow Control

Primary Benefits
Treatment
Volume Reduction (Incidental)
Peak Flow Attenuation (Optional)
BF-1 Biofiltration

E-121 January 2018
• Impermeable liner or uncompacted native soils at the bottom of the facility • Overflow structure

BF-1 Biofiltration

E-122 January 2018
Typical plan and Section view of a Biofiltration BMP
Design Adaptations for Project Goals
Biofiltration Treatment BMP for storm water pollutant control. The system is lined or un- lined to provide incidental infiltration, and an underdrain is provided at the bottom to carry away filtered runoff. This configuration is considered to provide biofiltration treatment via flow through the media layer. Storage provided above the underdrain within surface ponding, media, and aggregate storage is considered included in the biofiltration treatment volume. Saturated storage within the aggregate storage layer can be added to this design by raising the underdrain above the bottom of the aggregate storage layer or via an internal weir structure designed to maintain a specific water level elevation.

Integrated storm water flow control and pollutant control configuration. The system can be designed to provide flow rate and duration control by primarily providing increased surface ponding and/or having a deeper aggregate storage layer above the underdrain. This will allow for significant detention storage, which can be controlled via inclusion of an outlet structure at the downstream end of the underdrain.

Recommended Siting Criteria
Siting Criteria Intent/Rationale

□
Placement observes geotechnical
recommendations regarding potential hazards
(e.g., slope stability, landslides, liquefaction
zones) and setbacks (e.g., slopes, foundations,
utilities).

Must not negatively impact existing site
geotechnical concerns.
□
An impermeable liner or other hydraulic
restriction layer is included if site constraints
indicate that infiltration or lateral flows should
not be allowed.

Lining prevents storm water from
impacting groundwater and/or sensitive
environmental or geotechnical features.

Incidental infiltration, when allowable,
can aid in pollutant removal and
groundwater recharge.
□
Contributing tributary area shall be ≤ 5 acres (≤
1 acre preferred).

Bigger BMPs require additional design
features for proper performance.

Contributing tributary area greater than 5
acres may be allowed at the discretion of
the [City Engineer} if the following
conditions are met: 1) incorporate design
features (e.g. flow spreaders) to
minimizing short circuiting of flows in the
BF-1 Biofiltration

E-123 January 2018
Siting Criteria Intent/Rationale
BMP and 2) incorporate additional design
features requested by the [City Engineer]
for proper performance of the regional
BMP.
□ Finish grade of the facility is ≤ 2%. Flatter surfaces reduce erosion and channelization within the facility.

BF-1 Biofiltration

E-124 January 2018
Recommended BMP Component Dimensions
BMP Component Dimension Intent/Rationale
Freeboard ≥ 12 inches
Freeboard provides room for head
over overflow structures and
minimizes risk of uncontrolled
surface discharge.

Surface Ponding ≥ 6 and ≤ 12 inches
Surface ponding capacity lowers
subsurface storage requirements.

Deep surface ponding raises safety
concerns.

Surface ponding depth greater than
12 inches (for additional pollutant
control or surface outlet structures
or flow-control orifices) may be
allowed at the discretion of the [City
Engineer] if the following
conditions are met: 1) surface
ponding depth drawdown time is
less than 24 hours; and 2) safety
issues and fencing requirements are
considered (typically ponding
greater than 18” will require a fence
and/or flatter side slopes) and 3)
potential for elevated clogging risk
is considered.

Ponding Area Side Slopes 3H:1V or shallower
Gentler side slopes are safer, less
prone to erosion, able to establish
vegetation more quickly and easier
to maintain.

Mulch ≥ 3 inches
Mulch will suppress weeds and
maintain moisture for plant growth.

Aging mulch kills pathogens and
weed seeds and allows the beneficial
microbes to multiply.

BF-1 Biofiltration

E-125 January 2018
Media Layer ≥ 18 inches
A deep media layer provides
additional filtration and supports
plants with deeper roots. Standard
specifications shall be followed. For
non-standard or proprietary designs,
compliance with F.1 ensures that
adequate treatment performance
will be provided.

Underdrain Diameter ≥ 6 inches Smaller diameter underdrains are prone to clogging.

Cleanout Diameter ≥ 6 inches Properly spaced cleanouts will facilitate underdrain maintenance.

Design Criteria and Considerations
Bioretention with underdrain must meet the following design criteria. Deviations from the below criteria may be approved at the discretion of the [City Engineer] if it is determined to be appropriate:

Siting and Design Intent/Rationale
Surface Ponding
□
Surface ponding is limited to a 24-hour
drawdown time.

Surface ponding limited to 24 hours for
plant health. Surface ponding drawdown
time greater than 24-hours but less than
96 hours may be allowed at the discretion
of the [City Engineer] if certified by a
landscape architect or agronomist.

Vegetation
□
Plantings are suitable for the climate and
expected ponding depth. A plant list to aid in
selection can be found in Appendix E.20.

Plants suited to the climate and ponding
depth are more likely to survive.
□
An irrigation system with a connection to water
supply should be provided as needed.

Seasonal irrigation might be needed to
keep plants healthy.

Mulch (Optional or Mandatory – Dependent on jurisdiction ) □
A minimum of 3 inches of well-aged, shredded
hardwood mulch that has been stockpiled or
stored for at least 12 months is provided.

Mulch will suppress weeds and maintain
moisture for plant growth. Aging mulch
kills pathogens and weed seeds and allows
the beneficial microbes to multiply.

BF-1 Biofiltration

E-126 January 2018
Siting and Design Intent/Rationale
Media Layer
□
Media maintains a minimum filtration rate of 5
in/hr over lifetime of facility. An initial filtration
rate of 8 to 12 in/hr is recommended to allow
for clogging over time; the initial filtration rate
should not exceed 12 inches per hour.

A filtration rate of at least 5 inches per
hour allows soil to drain between events.

The initial rate should be higher than long
term target rate to account for clogging
over time. However an excessively high
initial rate can have a negative impact on
treatment performance, therefore an
upper limit is needed.
□
Media is a minimum 18 inches deep, meeting
either of these two media specifications:

Section F.3 Bioretention Soil Media (BSM) or
specific jurisdictional guidance.

Alternatively, for proprietary designs and
custom media mixes not meeting the media
specifications contained in the 2016 City Storm
Water Standards or County LID Manual, the
media meets the pollutant treatment
performance criteria in Section F.1.

A deep media layer provides additional
filtration and supports plants with deeper
roots.

Standard specifications shall be followed.

For non-standard or proprietary designs,
compliance with F.1 ensures that
adequate treatment performance will be
provided.
□
Media surface area is 3% of contributing area
times adjusted runoff factor or greater. Unless
demonstrated that the BMP surface area can be
smaller than 3%.

Greater surface area to tributary area
ratios: a) maximizes volume retention as
required by the MS4 Permit and b)
decrease loading rates per square foot and
therefore increase longevity.

Adjusted runoff factor is to account for
site design BMPs implemented upstream
of the BMP (such as rain barrels,
impervious area dispersion, etc.). Refer to
Appendix B.2 guidance.

Use Worksheet B.5-1 Line 26 to estimate
the minimum surface area required per
this criteria.
□
Where receiving waters are impaired or have a
TMDL for nutrients, the system is designed
with nutrient sensitive media design (see fact
sheet BF-2).

Potential for pollutant export is partly a
function of media composition; media
design must minimize potential for export
of nutrients, particularly where receiving
waters are impaired for nutrients.

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E-127 January 2018
Siting and Design Intent/Rationale
Filter Course Layer
□
A filter course is used to prevent migration of
fines through layers of the facility. Filter fabric
is not used.

Migration of media can cause clogging of
the aggregate storage layer void spaces or
subgrade. Filter fabric is more likely to
clog.
□ Filter course is washed and free of fines.

Washing aggregate will help eliminate
fines that could clog the facility and
impede infiltration.
□
Filter course calculations assessing suitability for
particle migration prevention have been
completed.

Gradation relationship between layers can
evaluate factors (e.g., bridging,
permeability, and uniformity) to
determine if particle sizing is appropriate
or if an intermediate layer is needed.

Aggregate Storage Layer
□
Class 2 Permeable per Caltrans specification 68-

1.025 is recommended for the storage layer.

Washed, open-graded crushed rock may be
used, however a 4-6 inch washed pea gravel
filter course layer at the top of the crushed rock
is required.

Washing aggregate will help eliminate
fines that could clog the aggregate storage
layer void spaces or subgrade.
□
The depth of aggregate provided (12-inch
typical) and storage layer configuration is
adequate for providing conveyance for
underdrain flows to the outlet structure.

Proper storage layer configuration and
underdrain placement will minimize
facility drawdown time.

Inflow, Underdrain, and Outflow Structures
□
Inflow, underdrains and outflow structures are
accessible for inspection and maintenance.

Maintenance will prevent clogging and
ensure proper operation of the flow
control structures.
□
Inflow velocities are limited to 3 ft/s or less or
use energy dissipation methods. (e.g., riprap,
level spreader) for concentrated inflows.

High inflow velocities can cause erosion,
scour and/or channeling.
□
Curb cut inlets are at least 12 inches wide, have
a 4-6 inch reveal (drop) and an apron and
energy dissipation as needed.

Inlets must not restrict flow and apron
prevents blockage from vegetation as it
grows in. Energy dissipation prevents
erosion.

BF-1 Biofiltration

E-128 January 2018
Siting and Design Intent/Rationale
□
Underdrain outlet elevation should be a
minimum of 3 inches above the bottom
elevation of the aggregate storage layer.

A minimal separation from subgrade or
the liner lessens the risk of fines entering
the underdrain and can improve hydraulic
performance by allowing perforations to
remain unblocked.
□ Minimum underdrain diameter is 6 inches. Smaller diameter underdrains are prone to clogging.
□
Underdrains are made of slotted, PVC pipe
conforming to ASTM D 3034 or equivalent or
corrugated, HDPE pipe conforming to
AASHTO 252M or equivalent.

Slotted underdrains provide greater intake
capacity, clog resistant drainage, and
reduced entrance velocity into the pipe,
thereby reducing the chances of solids
migration.
□
An underdrain cleanout with a minimum 6-inch
diameter and lockable cap is placed every 250 to
300 feet as required based on underdrain length.

Properly spaced cleanouts will facilitate
underdrain maintenance.
□
Overflow is safely conveyed to a downstream
storm drain system or discharge point Size
overflow structure to pass 100-year peak flow
for on-line infiltration basins and water quality
peak flow for off-line basins.

Planning for overflow lessens the risk of
property damage due to flooding.

Conceptual Design and Sizing Approach for Storm Water Pollutant Control Only To design bioretention with underdrain for storm water pollutant control only (no flow control required), the following steps should be taken:

1. Verify that siting and design criteria have been met, including placement requireme nts, contributing tributary area, maximum side and finish grade slope s, and the recommended media surface area tributary ratio.

2. Calculate the DCV per Appendix B based on expected site design runoff for tributary areas.

3. Use the sizing worksheet presented in Appendix B.5 to size biofiltration BMPs.

Conceptual Design and Sizing Approach when Storm Water Flow Control is Applicable Control of flow rates and/or durations will typically require significant surface ponding and/or aggregate storage volumes, and therefore the following steps should be taken prior to determination of storm water pollutant control design. Pre -development and allowable post-project flow rates and durations should be determined as discussed in Chapter 6 of the manual.

BF-1 Biofiltration

E-129 January 2018

1. Verify that siting and design criteria have been met, including placement requirements, contributing tributary area, maximum side and finish grade slope s, and the recommended media surface area tributary ratio.

2. Iteratively determine the facility footprint area, surface pondin g and/or aggregate storage layer depth required to provide detention storage to reduce flow rates and durations to allowable limits. Flow rates and durations can be controlled from detention storage by altering outlet structure orifice size(s) and/or water control levels. Multi-level orifices can be used within an outlet structure to control the full range of flows.

3. If bioretention with underdrain cannot fully provide the flow rate and duration control required by this manual, an upstream or downstream str ucture with significant storage volume such as an underground vault can be used to provide remaining controls.

4. After bioretention with underdrain has been designed to meet flow control requirements, calculations must be completed to verify if storm water p ollutant control requirements to treat the DCV have been met.

Maintenance Overview
Normal Expected Maintenance. Biofiltration requires routine maintenance to: remove accumulated materials such as sediment, trash or debris; maintain vegetation health; maint ain infiltration capacity of the media layer; replenish mulch; and maintain integrity of side slopes, inlets, energy dissipators, and outlets. A summary table of standard inspection and maintenance indicators is provided within this Fact Sheet.

Non-Standard Maintenance or BMP Failure. If any of the following scenarios are observed, the BMP is not performing as intended to protect downstream waterways from pollution and/or erosion. Corrective maintenance, increased inspection and maintenance, BMP replacement , or a different BMP type will be required.
• The BMP is not drained between storm events. 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 of the media layer, filter course, aggregate storage layer, underdrain, or outlet structure. The specific cause of the drainage issue must be determined and corrected.
• Sediment, trash, or debris accumulation greater than 25% of the surface ponding volume within one month. This means the load from the tributary drainage area is too high, reducing BMP function or clogging the BMP. This would require pretreatment measures within the tributary area draining to the BMP to intercept the materials. Pretreatment components, especially for sediment, will extend the life of components that are more expensive to replace such as media, filter course, and aggregate layers.

BF-1 Biofiltration

E-130 January 2018
• Erosion due to concentrated storm water runoff flow that is not readily corrected by adding erosion control blankets, adding stone at flow entry points, or minor re -grading to restore proper drainage according to the original plan. If the issue is not corrected by restoring the BMP to the original plan and grade, the [City Engineer] shall be contacted prior to any additional repairs or reconstruction.

Other Special Considerations . Biofiltration is a vegetated structural BMP. Vegetated structural BMPs that are constructed in the vicinity of, or connected to, an existing jurisdictional water or wetland could inadvertently result in creation of expanded waters or wetlands. As such, vegetated structural BMPs have the potential to come under the juris diction of the United States Army Corps of Engineers, SDRWQCB, California Department of Fish and Wildlife, or the United States Fish and Wildlife Service. This could result in the need for specific resource agency permits and costly mitigation to perform maintenance of the structural BMP. Along with proper placement of a structural BMP, routine maintenance is key to preventing this scenario.

Sediment Loading. Consider the effects of BMP design and tributary area land uses on the clogging potential of the BMP. Complete the sediment loading analysis included in Appendix E.27.

BF-1 Biofiltration

E-131 January 2018
Summary of Standard Inspection and Maintenance
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 ow ners 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 prese nted 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 Accumulation of sediment, litter, or debris Remove and properly dispose of accumulated materials, without damage to
the vegetation or compaction of the media
layer.
• Inspect monthly. If the BMP is 25% full*
or more in one month, increase inspection
frequency to monthly plus after every 0.1-
inch or larger storm event.
• Remove any accumulated materials found
at each inspection.

Obstructed inlet or outlet structure Clear blockage. • Inspect monthly and after every 0.5-inch or larger storm event.
• Remove any accumulated materials found
at each inspection.

Damage to structural components such as
weirs, inlet or outlet structures
Repair or replace as applicable • Inspect annually.
• Maintain when needed.

BF-1 Biofiltration

E-132 January 2018
Threshold/Indicator Maintenance Action Typical Maintenance Frequency Poor vegetation establishment Re-seed, re-plant, or re-establish vegetation per original plans.

• Inspect monthly.
• Maintain when needed.

Dead or diseased vegetation Remove dead or diseased vegetation, re- seed, re-plant, or re-establish vegetation per
original plans.
• Inspect monthly.
• Maintain when needed.

Overgrown vegetation Mow or trim as appropriate. • Inspect monthly. • Maintain when needed.
2/3 of mulch has decomposed, or mulch
has been removed
Remove decomposed fraction and top off
with fresh mulch to a total depth of 3
inches.
• Inspect monthly.
• Replenish mulch annually, or more
frequently when needed based on
inspection.

Erosion due to concentrated irrigation flow Repair/re-seed/re-plant eroded areas and adjust the irrigation system.
• Inspect monthly.
• Maintain when needed.

BF-1 Biofiltration

E-133 January 2018
Threshold/Indicator Maintenance Action Typical Maintenance Frequency Erosion due to concentrated storm water
runoff flow
Repair/re-seed/re-plant eroded areas, and
make appropriate corrective measures such
as adding erosion control blankets, adding
stone at flow entry points, or minor re-
grading to restore proper drainage according
to the original plan. If the issue is not
corrected by restoring the BMP to the
original plan and grade, the [City Engineer]
shall be contacted prior to any additional
repairs or reconstruction.
• Inspect after every 0.5-inch or larger storm
event. If erosion due to storm water flow
has been observed, increase inspection
frequency to after every 0.1-inch or larger
storm event.
• Maintain when needed. If the issue is not
corrected by restoring the BMP to the
original plan and grade, the [City Engineer]
shall be contacted prior to any additional
repairs or reconstruction.

Standing water in BMP for longer than 24
hours following a storm event
Surface ponding longer than approximately
24 hours following a storm event may be
detrimental to vegetation health
Make appropriate corrective measures such
as adjusting irrigation system, removing
obstructions of debris or invasive
vegetation, clearing underdrains, or
repairing/replacing clogged or compacted
soils.
• 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.
• Maintain when needed.

BF-1 Biofiltration

E-134 January 2018
Threshold/Indicator Maintenance Action Typical Maintenance Frequency Presence of mosquitos/larvae

For images of egg rafts, larva, pupa, and
adult mosquitos, see
http://www.mosquito.org/biology

If mosquitos/larvae are observed: first,
immediately remove any standing water by
dispersing to nearby landscaping; second,
make corrective measures as applicable to
restore BMP drainage to prevent standing
water.

If mosquitos persist following corrective
measures to remove standing water, or if the
BMP design does not meet the 96-hour
drawdown criteria due to release rates
controlled by an orifice installed on the
underdrain, the [City Engineer] shall be
contacted to determine a solution. A
different BMP type, or a Vector
Management Plan prepared with
concurrence from the County of San Diego
Department of Environmental Health, may
be required.
• 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.
• Maintain when needed.

Underdrain clogged Clear blockage. Inspect if standing water is observed for longer than 24-96 hours following a storm
event.

Maintain when needed.
“25% full” is defined as ¼ of the depth from the design bottom elevation to the crest of the outflow structure (e.g., if the height to the outflow opening is 12 inches from the bottom elevation, then the materials must be removed when there is 3 inches of accumulation – this should be marked on the outflow structure).

City of San Marcos PDP SWQMP Template Date: March 15, 2016 PDP SWQMP Preparation Date: May 12, 2023
ATTACHMENT 4
Copy of Plan Sheets Showing Permanent Storm Water BMPs

This is the cover sheet for Attachment 4.

Use this checklist to ensure the required information has been included on the plans:

The plans must identify:

 Structural BMP(s) with ID numbers matching Form I-6 Summary of PDP Structural BMPs  The grading and drainage design shown on the plans must be consistent with the delineation of DMAs shown on the DMA exhibit
 Details and specifications for construction of structural BMP(s)  Signage indicating the location and boundary of structural BMP(s) as required by the [City Engineer]  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  Maintenance thresholds specific to the structural BMP(s), with a location-specific frame of reference (e.g., level of accumulated materials that triggers removal of the materials, to be identified based on viewing marks on silt posts or measured with a survey rod with respect to a fixed benchmark within the BMP)
 Recommended equipment to perform maintenance
 When applicable, necessary special training or certification requirements for inspection and maintenance personnel such as confined space entry or hazardous waste management  Include landscaping plan sheets showing vegetation requirements for vegetated structural BMP(s)  All BMPs must be fully dimensioned on the plans
 When proprietary BMPs are used, site-specific cross section with outflow, inflow, and model number shall be provided. Photocopies of general brochures are not acceptable.

MWS 8-20
LOT 1
CITY OF SAN MARCOSPARCELAPN 219-152-74
15SHEET OF
TENTATIVE SUBDIVISIONMAPTSM22-0002GNIREEN EIGN6390 Greenwich Dr., Suite 170San Diego, California 92122tel 858.554.1500 fax 858.597.0335www.fuscoe.comCONCEPTUAL GRADING AND UTILITIES

CONCEPTUAL GRADING PLAN
CONCEPTUAL GRADING PLANFOR TENTATIVE SUBDIVISION MAP NO. TSM22-0002

SHEET INDEX
TOPOGRAPHY NOTE:

UTILITY PROVIDERS

SCHOOL DISTRICT

FLOOD ZONE INFORMATION

OWNER/DEVELOPER
ASSESSOR'S PARCEL NUMBERS:

INTERIM EMERGENCY ACCESS ROAD

BENCHMARK
4 TYPICAL SECTIONS25SHEET OF
TENTATIVE SUBDIVISIONMAPTSM22-0002GNIREEN EIGN6390 Greenwich Dr., Suite 170San Diego, California 92122tel 858.554.1500 fax 858.597.0335www.fuscoe.com RIBBON GUTTER DETAIL0" CURB
20' AC PAVING ALLEY2.33'
12' LANE12' LANE

LANDSCAPING

8.1' MAX2.33'

PROPOSED C&G
SECTION2 B-B SECTION 2A-A
SECTION 2C-CSECTION2D-D
10' MIN.

LANDSCAPE75' MAX LANDSCAPEEX. & PROP.PROPERTY LINE
LANDSCAPE/WALKWAYBIOFILTRATIONPROP. PROPERTY LINE

4.4'9.5'MIN2.6'MIN
CREEK ANDCONSERVATIONEASEMENT18.2' MIN6.75'MIN
WALKWAY CONNECTINGTO BUILDING1.7 MIN
PROPOSED OPENSPACE PATIOWALKWAY12.8'MAX
INTERNAL ROAD SECTION (RES)2A
INTERNAL ROAD SECTION (RES)2B
INTERNAL ROAD SECTION (RES)2D
24' AC PAVING ALLEY

2.33'
18' PARKING5'3.5' MIN 2.33'
VAN ACCESSIBLE PARKING23 STANDARD PARKING21COMPACT PARKING22 CURB16'8.5' CURB18'9'
12'18'
13' LANE13' LANE 9' MIN
INTERNAL ROAD SECTION (RES)2C
4'
5'5' MAXLANDSCAPE
5'

CONCEPTUAL GRADING PLAN

PROPOSED C&G
5'8.5' MIN

WEDGE CURB
20' AC PAVING ALLEY2.33' 2.33'
18'1.5'
INTERNAL ROAD SECTION (RES)2E
EX. PROPERTY LINE1.5 MIN
PROP. PROPERTY LINEEX. PROPERTY LINE

5.9' MIN
NO SLOPE WITH 2 WALLS(BMP 2)
FULLY IN-GROUND(BMP 1)

BIOFILTRATION BASIN DETAILNOT TO SCALE

SIDEWALKBIOFILTRATIONLANDSCAPESIDEWALK
EX. & PROP.PROPERTY LINE
5'6'BIKE PATH

GRAND AVE
17'

GRAND AVENUESEE STREET SECTION
R/W

4.5'1.4'5'MINSTREET TREE PERDETAIL AA
1'4'4.5'

ROW EASEMENT LINE

2.5'
AA2 STREET TREE (GRAND AVE)

CREEK ANDCONSERVATIONEASEMENT

GRAND AVENUE STREET SECTIONNOT TO SCALE
12' LANE10'LANDSCAPEMEDIAN33'66'33'EX. PL EX. R/W
EX. C&G
℄
PROPOSED& EX.C&G
12' LANE26'7'
EX. PAVEMENTTO REMAIN
32'5.5'6'BIKEPATH5'S/W
PROPOSEDAC BIKE PATHPROPOSED DG ORCONC. SIDEWALK
EX. R/W ESMT
12' LANE12' LANE
EX. R/W ESMT0.5' MIN

MEDIAN PLANTINGAND SOILS PERLANDSCAPE PLANS
6" VINE PLANTINGSTRIP PERLANDSCAPE PLANS

EXISTING SEWEREXISTINGWATER
83'
PROPOSEDSEWERPROPOSEDPRIVATE WATERPROPOSEDPRIVATEFIRE LINE6'2'11'5' EXISTING15" VWDSEWER
PROPOSEDPRIVATEFIRE LINE1'22.5'2.5'
EXISTING 20' VWD EASEMENT PER
PROPOSEDSEWERPROPOSEDPRIVATE WATERPROPOSEDPRIVATEFIRE LINE7'12'2'3' 4 35SHEET OF
TENTATIVE SUBDIVISIONMAPTSM22-0002GNIREEN EIGN6390 Greenwich Dr., Suite 170San Diego, California 92122tel 858.554.1500 fax 858.597.0335www.fuscoe.com

PARKING AND CIRCULATION PLAN

CONCEPTUAL GRADING PLAN
PROPRIETARY BIOFILTRATION DETAILMODULAR WETLANDS MWS-L-8-20-VNOT TO SCALE

URBANPOND PRECAST CONCRETESTORMWATER DETENTION MODULEBY BIOCLEANNOT TO SCALE 4 CITY OF SAN MARCOSPARCELAPN 219-152-74-00
PARCEL C OF COC REC DOCNO 2019-0160631APN 219-152-77-00PARCEL B OF COC REC DOCNO 2019-0160631APN 219-152-76-00 45SHEET OF
TENTATIVE SUBDIVISIONMAPTSM22-0002GNIREENE IGN6390 Greenwich Dr., Suite 170San Diego, California 92122tel 858.554.1500 fax 858.597.0335www.fuscoe.com4SIGHT DISTANCE EXHIBIT

San Marcos City CouncilOctober 24, 2023

San Marcos City Council
October 24, 2023