Storm Water Program - Caltrans Permits (Statewide)


Pursuant to the Federal Water Pollution Control Act (Clean Water Act) section 402(p), storm water permits are required for discharges from a municipal separate storm sewer system (MS4) serving a population of 100,000 or more. USEPA defines an MS4 as a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains) owned or operated by a State (40 CFR 122.26(b)(8)).

The California Department of Transportation (Caltrans) is responsible for the design, construction, management, and maintenance of the State highway system, including freeways, bridges, tunnels, Caltrans’ facilities, and related properties. Caltrans’ discharges consist of storm water and non-storm water discharges from State owned right-of-ways.

Before July 1999, storm water discharges from Caltrans’ storm water systems were regulated by individual NPDES permits issued by the Regional Water Boards. On July 15, 1999, the State Water Board issued a statewide permit (Order No. 99-06-DWQ) which regulated all storm water discharges from Department owned MS4s, maintenance facilities and construction activities. The existing permit (Order No. 99-06-DWQ) will be replaced upon adoption of a new permit.

Caltrans’ Storm Water Management Plan (SWMP) describes the procedures and practices used to reduce or eliminate the discharge of pollutants to storm drainage systems and receiving waters. The SWMP will be considered for approval by the State Water Board along with the new permit.

  • Caltrans General Permit & Forms

  • Caltrans Storm Water Management Plan Public Comments
    The public was invited to comment on the proposed revised Storm Water Management Plan (SWMP) submitted by the California Department of Transportaton (Caltrans) on June 29, 2007.

    Disclaimer and Notes

The NPDES Permit PDF documents might be formatted differently than the hard copies. We are in the process of reformating the permit PDF files to match the format on the hard copies. Most forms in Adobe Acrobat may be filled out electronically.

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