The Stormwater Utility Division operates and maintains 620 miles of pipe, 72 pump stations, and over 100 discharge pipes that collect and route runoff from the streets and gutters to our local rivers, creeks, and sloughs.

The Stormwater Divison also manages the City’s National Pollutant Discharge Elimination Permit (NPDES). The NPDES Stormwater Program regulates stormwater discharges from:

  • Construction activities
  • Industrial activities
  • Municipal stormwater system

Municipal Stormwater System

Stormwater runoff occurs when precipitation from rain and snow melts does not absorb into the ground. As the runoff flows over the land or impervious surfaces (paved streets, parking lots, and rooftops), it accumulates debris, chemicals, and other pollutants that could adversely affect water quality.

Stockton’s stormwater is collected in catch basins and transported, untreated, directly into local rivers, creeks, and sloughs, and eventually to the Delta. Best management practices (BMPs) is the primary method to stop contaminants from entering the system.

Municipal Separate Storm Sewer System (MS4) permits are required under the Clean Water Act and require the discharger to develop and implement a Storm Water Management Plan to reduce the discharge of pollutants to the Maximum Extent Practicable (MEP). 

Each year the City must provide an Annual Report to the State on the Stormwater Program and BMPs.

Construction Activities

Operators of construction sites on one-acre or larger, including smaller sites part of a larger common plan of development, are monitored under the State’s Construction General Permit. The Stormwater Program also requires specific control measures for post-construction runoff from new developments and redeveloped areas. 

The Stormwater Quality Control Criteria Plan (SWQCCP) provides development standards on these controls, including general site control measures, site-specific source control measures, and treatment control measures for the following:

  • Home subdivisions with 10 or more housing units
  • Commercial developments with impervious areas greater than 5,000 sq. ft.
  • Automotive repair shops with impervious areas greater than 5,000 sq. ft.
  • Restaurants
  • Parking lots greater than 5,000 sq. ft. or with 25 or more parking spaces
  • Streets and roads with one acre or more of impervious area
  • Retail gas outlets with 5,000 or more sq. ft. of impervious area

Construction Stormwater Regulations and Best Management Practices

Overview of Federal, State and local stormwater regulations:

Flyer of various BMPS that may be implemented on construction sites:

Industrial Activities

The Stormwater Program works with local industries to prevent stormwater pollution using:

Industrial companies may require authorization under an NPDES industrial stormwater permit for stormwater discharges.

Related Documents 


External Links

State Water Resources Control Board - Stormwater Permits

Stormwater Pollution Prevention Plans 

This City of Stockton web page last reviewed on --- 4/5/2019