Stormwater home page City of Los Angeles home page
      Department of Public Works Bureau of Sanitation
Related Internal Links

Main SUSMP Page

Flow Chart of the Plan Review and Approval Process

What to Submit?


Redevelopment Definition

Development BMPs Handbook Part B: Planning Activities

SUSMP Conference

Contact Us

Related External Links

State Water Resources Control Board SUSMP Website


On December 13, 2001, the Regional Water Quality Control Board issued a Municipal Storm Water National Pollutant Discharge Elimination System Permit (NPDES Permit No. CAS004001) that requires new development and redevelopment projects to incorporate storm water mitigation measures, effective September 2, 2002.

Depending on the type of project, either a Standard Urban Stormwater Mitigation Plan (SUSMP) or a Site Specific Mitigation Plan is required to reduce the quantity and improve the quality of rainfall runoff that leaves the site. Developers are encouraged to begin work on complying with these regulations by visiting the Watershed Protection Division (WPD) in the design phase of their projects.

SUSMP  Project Categories:roject Categories:

Site Specific Project Categories:

  • Vehicle or Equipment Fueling Areas
  • Vehicle or Equipment Maintenance Areas, including Washing and Repair
  • Commercial or Industrial Waste Handling or Storage
  • Outdoor Handling or Storage of Hazardous Materials
  • Outdoor Manufacturing Areas
  • Outdoor Food Handling or Processing
  • Outdoor Animal Care, Confinement, or Slaughter
  • Outdoor Horticultural Activities
  • Major Transportation Projects


Example of stencil


√íRedevelopment√ď means, "…any land-disturbing activity that results in the creation, addition, or replacement of 5,000 square feet or more of impervious surface area on an already developed site. Redevelopment includes, but is not limited to: the expansion of a building footprint; addition or replacement of a structure; replacement of impervious surface area when replacement is not part of a routine maintenance activity; and land-disturbing activities related to structural or impervious surfaces.

It does not include routine maintenance activities that are conducted to maintain original line and grade, hydraulic capacity, or original purpose of facility, nor does it include emergency construction activities required to immediately protect public health and safety.

Existing "non-hillside" single-family structures are exempt from the redevelopment requirements."

  • If redevelopment results in an alteration to more than fifty percent of the existing development, then the entire project must be mitigated.
  • If redevelopment results in an alteration to less than fifty percent of the existing development, and the existing development was not subject to storm water quality control requirements, then only the alteration must be mitigated.

Back to top of page