California Integrated Report - 303(d) List of Water Quality Limited Segments and 305(b) Condition Report
The federal Clean Water Act (“CWA”) requires that California report on the quality of its surface waterbodies (such as rivers, streams, reservoirs, bays, etc.) every two years. California develops the integrated report to meet this requirement. The integrated report consists of the CWA section 303(d) impaired waters list and the 305(b) condition report. The California Integrated Report is developed in “cycles” with submittal to the U.S. Environmental Protection Agency (“USEPA”) every two years. Each cycle consists of data assessments from waters within three Regional Water Quality Control Board regions. The other six regions may be considered “off-cycle” and assess high-priority data.
Placing a waterbody on the 303(d) list initiates the prioritization of total maximum daily load (“TMDL”) development, or another alternative restoration project, to restore and maintain water quality standards. The USEPA compiles the 305(b) reports from all states, territories, and tribes, and submits the summaries in their “National Water Quality Inventory Report” to the U.S. Congress.
Since the 2020-2022 California Integrated Report cycle, the State Water Resources Control Board (“State Water Board”) has been administering the public process, including board hearings and development of the staff report. While the Regional Water Boards play a significant role in the development of the integrated report, the Regional Water Boards no longer conduct individual board hearings and public comment periods. All public documents are available on the State Water Board Surface Water Quality Assessment program webpage. Introductory information of the California Integrated Report can be found in the Fact Sheet.
To receive email updates from the State Water Board about the integrated report, under their Water Quality tab, please subscribe to their Integrated Report – 303(d)/305(b) email list.
2024 California Integrated Report (Clean Water Act section 303(d) list and 305(b) report
- Partial approval and partial disapproval of the 2024 California Integrated Report from USEPA
- Final 2024 California Integrated Report
- 2024 Integrated Report Map
For the 2024 Integrated Report, the Los Angeles Regional Water Board conducted on-cycle assessments.
2018 California Integrated Report (Clean Water Act Section 303(d) List and 305(b) Report)
- Final 2018 California Integrated Report
- 2018 Integrated Report Map
For the 2018 Integrated Report, the Los Angeles Regional Water Board conducted off-cycle assessments for several water bodies in Ventura County.
2016 California Integrated Report (Clean Water Act Section 303(d) List and 305(b) Report)
- Additional information on the 303(d) list can be found on State Boards website under Impaired Water Bodies
- The current 303(d) list can be found on the State Water Board website. This is the final 2014/2016 list.
For the 2016 assessment cycle, the Section 303(d) List and Section 305(b) Water Quality Assessment Report are combined into a single "Integrated Report" to satisfy the requirements of both sections of the CWA. The process involves separate actions by Regional Water Boards on recommendations to the State Water Board. The State Water Board will compile and approve a statewide Integrated Report and submit it to the USEPA for final approval.
Subscribe to Receive Email Notifications
-
To receive information and notices on the Integrated Report, please subscribe using the following link:
- Los Angeles Regional Water Quality Control Board - 303(d) List of Impaired Water Bodies (under “Subscription Topics”, expand “Basin Planning” drop down menu)
Questions or Comments?
Environmental Scientist
LA Regional Water Quality Control Board
320 West 4th Street, Suite 200
Los Angeles, CA 90013
Telephone: (213) 576-6619
303(d) Lists Addressing the
Los Angeles Region
(Page last updated 2/8/25)
Water is a precious resource in California, and maintaining its quality is of utmost importance to safeguard the health of the public and the environment.