Best Management Practice Design Manual


The County of San Diego BMP Design Manual (BMP DM) provides guidance for land development and public improvement projects to comply with the 2013 Municipal Separate Storm Sewer System (MS4) Permit (Order No. R9-2013-0001 as amended by R9-2015-0001 and R9-2015-0100). This Manual replaces County of San Diego Standard Urban Stormwater Mitigation Plan (SUSMP). It is focused on project design requirements and related post-construction requirements, not on the construction process itself.
The County’s regulatory programs for stormwater are established in County ordinances, principally the  County of San Diego Watershed Protection, Stormwater Management, and Discharge Control Ordinance  (WPO), at County Code sections 67.801 et seq. The WPO defines the requirements that are legally enforceable by the County in the unincorporated parts of San Diego County.



For technical questions regarding the BMP Design Manual, contact the Model BMP Design Manual Help Desk through email as described here.

Non-technical questions related to County-specific requirements such as submittal requirements, approval process, project-specific questions and policy-related issues should be directed to the PDS Land Development Project Manager.



BMP Design Manual Chapters Effective February 26 2016

Handouts on Supplemental Guidance (To be included in next Manual update)

BMP Design Manual Appendices (Complete)


Response to Public Comments


Helpful Information and Documents:

Low Impact Development (LID) Handbook
San Diego County ArcGIS Online Mapping Application (includes following data)

  • 85th Percentile Precipitation Map
  • County of San Diego Watershed Finder

SanGIS Regional Data Warehouse (Includes the following GIS layers)

  • Environmentally_Sensitive_Areas
  • Isopluvials_85th_Percent
  • Water_Quality_Sensitive_Areas_SD
  • Watersheds
  • Wetlands
  • Soils
  • Flood_Plain
  • Hydrologic_Basins
  • Lagoons
  • Lakes
  • Major_Streams
  • Streams

Hydromodification Management Exemption Mapping
Potential Critical Coarse Sediment Mapping
Resource Protection Ordinance
Operation and Maintenance Cost Table for Treatment Control BMPs
Maintenance Notification Agreement for Category 1 Stormwater Structural BMP’s
Storm Water Facilities Maintenance Agreement Instructions
San Diego Countywide Hydromodification Plan 
Grading Ordinance
Hydraulic Design Manual
Hydrology Manual