City of San Diego

Stormwater Standards

CityCaliforniamediumNeeds review

This extraction needs human review.

Local queue text is truncated relative to full ~786-page PDF; core pollutant-control DCV (85th percentile), hydromodification 0.1–0.5Q2 to Q10, and BMP category table are well supported. Appendix G software section body is incomplete in the local text—SDHM and EPA SWMM appear in sizing/appendix excerpts. 100-year appears mainly in floodplain/exemption context, not as pollutant-control design storm.

Other manuals in California: California, California Department of Transportation (Caltrans), County of Los Angeles

Document Metadata

Jurisdiction level

municipality

“The City of San Diego (City) is required to adopt jurisdiction specific local BMP Design Manual”
Introduction / Purpose

State

California

“California Regional Water Quality Control Board for the San Diego Region (SDRWQCB)”
Purpose of the Storm Water Standards

Version / edition

August 2024 Edition

“The City of San Diego | Stormwater Standards | August 2024 Edition”
Header / Title

Adoption / effective date

2024-08-15

“Effective date: August 15, 2024”
Title Page

Last revised date

2024-08

“August 2024 Edition”
Title Page / Headers

Relationship to state manual

independent

“Part 1 of the Stormwater Standards is the adaption of the Model BMP Design Manual to the specific... Standards is designated as the City of San Diego BMP Design Manual”
Introduction

Design Criteria

Design storm return periods (years)

2-year, 10-year, 100-year

“For flow rates ranging from 10 percent, 30 percent or 50 percent of the pre-development 2-year runoff event (0.1Q2, 0.3Q2, or 0.5Q2) to the pre-development 10-year runoff event (Q10), the post-project discharge rates and durations must not exceed the pre-development rates and durations by more than 10 percent”
Section 6.3, Page 6-4

Water quality volume method

Design Capture Volume (DCV): retain onsite pollutants in runoff from the 24-hour, 85th percentile storm event (Figure B.1-1 or approved site-specific analysis). If full retention is not technically feasible, biofiltration for remaining volume (treat 1.5× DCV not retained, or flow-thru biofiltration holding ≥0.75× DCV not retained); otherwise flow-thru treatment (0.2 in/hr or 85th percentile hourly intensity × 2) plus alternative compliance.

“Each PDP shall implement BMPs that are designed to retain (i.e. intercept, store, infiltrate, evaporate, and evapotranspire) onsite the pollutants contained in the volume of stormwater runoff produced from a 24-hour, 85th percentile storm event (Design Capture Volume (DCV))”
Section 2.2.1, Page 2-5

Peak flow calculation method(s)

Continuous simulation hydrologic modeling, Approved Q2/Q10 regression equations, Rational method (runoff to BMPs)

“Q2 and Q10 refer to flow rates determined based on either continuous simulation hydrologic modeling or the following approved regression equations”
Section 6.3, Page 6-4

Required hydrologic/hydraulic software

San Diego Hydrology Model (SDHM), EPA SWMM

“through reporting of output from the San Diego Hydrology Model, or through other continuous simulation modeling meeting the criteria in Appendix G, as acceptable to the City Engineer”
Appendix B.4, Page B-28

Approved BMP categories

Harvest and Use (HU-1: Cistern), Infiltration (INF-1: Infiltration basin), Bioretention (INF-2), Permeable pavement (INF-3), Dry Wells (INF-4), Biofiltration with Partial Retention (PR-1), Biofiltration (BF-1), Nutrient Sensitive Media Design (BF-2), Proprietary Biofiltration (BF-3), Vegetated swales (FT-1), Media filters (FT-2), Sand filters (FT-3), Dry extended detention basins (FT-4), Proprietary flow-thru treatment control (FT-5)

“Retention Harvest and Use (HU) HU-1: Cistern; Retention Infiltration (INF) INF-1: Infiltration basin INF-2: Bioretention INF-3: Permeable pavement INF-4: Dry Wells; Partial Retention (PR) PR-1: Biofiltration with partial retention; Biofiltration (BF) BF-1: Biofiltration BF-2: Nutrient Sensitive Media Design BF-3: Proprietary Biofiltration; Flow-thru treatment control (FT) FT-1: Vegetated swales FT-2: Media filters FT-3: Sand filters FT-4: Dry extended detention basins FT-5: Proprietary flow-thru treatment control”
Section 5.5 / Table, Page 5-13