Stormwater Reports
Monitoring and Characterization Studies
CTSW-RT-03-065.51.42 (PDF)
Discharge Characterization Study Report
November 2003
Overview of the Department stormwater characterization activities, descriptions of the methods used to produce and evaluate the data, results of the characterization monitoring and data analysis, and conclusions pertinent to management of stormwater runoff from transportation facilities.
CTSW-RT-03-028 (PDF)
Roadside Vegetated Treatment Sites (RVTS) Study
November 2003
Study to evaluate the removal of stormwater contaminants by existing vegetated slopes adjacent to freeways.
CTSW-RT-00-016 (PDF)
Caltrans 1999/2000 First Flush Study Report
June 2000
Presents the results of the first flush characterization study conducted at three highway sites in District 7.
New Technology
CTSW-RT-01-050 (PDF)
BMP Retrofit Pilot Program - Final Report
January 2004
Pilot program to acquire experience in the installation and operation of a wide range of structural BMPs for treating stormwater runoff from existing Caltrans facilities and to evaluate the performance and costs of these devices.
Public Education
Stormwater Management Plan and Permit
NPDES Permit Order 2022-0033-DWQ and Stormwater Management Plan (December 2024) supersede the previously approved permit and SWMP.
Statewide Stormwater Management Plan (PDF) (December 2024)
Caltrans NPDES Statewide Stormwater Permit (PDF) (June 2022)
Statewide Stormwater Management Plan (PDF) (July 2016)
Caltrans NPDES Statewide Stormwater Permit (PDF) (September 2012)