TMDL - The Integrated Report
303(d) List of Water Quality Limited Segments and 305(b) Surface Water Quality Assessment
Section 303(d) of the Clean Water Act requires the identification of water bodies that do not meet, or are not expected to meet, water quality standards (i.e., impaired water bodies). The affected water body, and associated pollutant or stressor, is then prioritized in the 303(d) List. The Clean Water Act further requires the development of a Total Maximum Daily Load (TMDL) for each listing. In 2008, California began integrating the 303(d) List of Impaired Waters and the 305(b) Water Quality Assessment Report into a single report (Integrated Report). This Integrated Report will satisfy the requirements of both CWA Sections 303(d) and 305(b).
Since the 2020-2022 California Integrated Report cycle, the State Water Board has been administering the public process, including board hearings and development of the integrated 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’s program webpage. More background information on the Integrated Report can be found in the State Water Board’s Fact Sheet.
What's New!
2028 Integrated Report - IN PROGRESS
The Central Valley Water Board will assess all readily available data for waters in the Sacramento – San Joaquin River Delta and the Tulare Lake Basin. Readily available data for the Sacramento River and the San Joaquin River watersheds will be considered during future Integrated Report Cycles. The data solicitation period closed on October 23, 2024. More information on the 2028 Integrated Report can be found on the State Water Board website:
2026 Integrated Report - Public Review and Comment Period: January 30 - April 2, 2025
The Central Valley Water Board will assess all readily available data for waters in the San Joaquin River watershed. The State Water Board released the draft 2026 Integrated Report, including the draft 2026 303(d) list of impaired water bodies, and accompanying draft Staff Report on January 30, 2025. A staff-hosted Public Workshop was held on February 11, 2025. A public hearing to receive oral comments on the draft 2026 303(d) list will be held on March 18, 2025. The public comment period will close on April 2, 2025. More information on the 2026 Integrated Report cycle, including the Notice of Opportunity for Public Comment, Public Staff Workshop, and Public Hearing, can be found on the State Water Board website:
2024 Integrated Report - The Current 303(d) List
The Central Valley Water Board assessed all readily available data for waters in the Sacramento River watershed. Readily available data for the San Joaquin River watershed, the Sacramento - San Joaquin River Delta, and the Tulare Lake Basin will be considered during future Integrated Report cycles. The State Water Board held an adoption hearing on February 6, 2024, and adopted the 2024 Integrated Report. U.S. EPA issued a partial Approval and Partial Disapproval of the 2024 Integrated Report. More information on the 2024 Integrated Report for California can be found on the State Water Board website:
2020-2022 Integrated Report
The Central Valley Water Board assessed all readily available data for waters in the Central Valley Region. The 2020-2022 Integrated Report was adopted by the State Water Board on January 19, 2022, and approved by U.S. EPA on May 11, 2022.
Integrated Report Listing Policy
The Water Quality Control Policy for Developing California’s Clean Water Act Section 303(d) List describes the process by which the State Water Resources Control Board and Regional Water Quality Control Boards will comply with the listing requirements of section 303(d) of the federal Clean Water Act.
Email Subscription List
Subscribe to the Impaired Waterways 303(d) List email list to receive notifications and updates.
Contact Us
- Program Contact
Jay Simi
(916) 464-4833
Jay.Simi@waterboards.ca.gov
- Web page problems: webmaster5@waterboards.ca.gov
