Colorado River Basin Integrated Report (303(d) List and 305(b) Report)

2026 Integrated Report

Proposed revisions to the 303(d) list for the Colorado River Basin

The Draft 2026 303(d) List and supporting draft staff report are a coordinated and combined effort among the State and Regional Water Boards. The Draft 2026 303(d) List and supporting draft staff report are available for review and comment from January 30 to April 2, 2025. A staff-hosted public workshop will be held on February 11, 2025. A State Water Board public hearing will be held on March 18, 2025. The following documents are available:

2018 Integrated Report

Final 2018 303(d) List

Proposed revisions to the 303(d) list for the Colorado River Basin

The Draft 2018 303(d) List and supporting draft staff report were available for review and comment The Regional Board opened a public comment period on proposed revisions to the 303(d) list of impaired water bodies in the Colorado River Basin from October 1, 2019 to October 28, 2019. A staff-hosted public workshop was held on October 10, 2019. The Regional Board Hearing on the proposed revisions was held on November 14, 2019. The Regional Board Hearing was held on November 14, 2019. At the hearing, the Regional Board approved each proposed listing change and adopted Resolution R7-2019-0054 in support of its recommendations to the State Water Resources Control Board (State Water Board) for the statewide 2018 303(d) list. The following documents are available:

Pre-2018 Integrated Reports

California Integrated Reports not included on this webpage are available on the State Water Board site, Historical Integrated Reports.

Questions or Comments?

For more information, please visit the State Water Board’s web pages for the TMDL Program and Impaired Water Bodies.

Project Manager
Emma McCorkle, Senior Environmental Scientist
Email: Emma.McCorkle@waterboards.ca.gov
Phone: (760) 340-4521