Integrated Report Cycles – Clean Water Act Sections 303(d) and 305(b)

California’s Clean Water Act section 303(d) and 305(b) Integrated Report is developed in "cycles" with each cycle occurring every two years. Each Integrated Report cycle consists primarily of assessments from the three Regional Water Quality Control Boards that are identified "on-cycle" by the notice of solicitation The other six Regional Water Quality Control Boards that are "off-cycle" may also assess new high-priority data and make new listing or delisting decisions for one or more water segments.

Below is an overview of the process and approximate schedule used in developing the Integrated Report. The chart is not reflective of any particular "cycle" but generally depicts the amount of time that corresponds to each of the steps necessary to complete a single cycle.

Steps Approx. Months
1. Data Solicitation 6
2. Data Organization & Mapping 5
3. Data Analysis 13
4. Regional Board Public Process 10
5. State Board Public Process 10
6. USEPA Review & Approval 3

In Progress: 2024, 2020-2022 | Current: 2018 | Previous


2024 Integrated Report - In Progress

The 2024 Integrated Report is currently in progress. The 2024 California Integrated Report listing cycle will be conducted for the “on-cycle” Regional Water Quality Control Boards (“Regional Water Boards”) for the San Francisco, Los Angeles, and Santa Ana regions. The Central Valley Regional Water Board will be conducting “off-cycle” assessments for waters within the Sacramento River sub-area. The Sacramento River sub-area is defined as the Sacramento River watershed. It includes the mainstem of the Sacramento River above the legal boundary of the Sacramento-San Joaquin Delta and all surface waters tributary to the mainstem. The other five Regional Water Boards would be considered “off cycle” for the 2024 Integrated Report but the listing process may be administered for one or more waters at the Regional Water Board’s or the State Water Board’s discretion.

2020-2022 Integrated Report - In Progress

As updated here, the California Integrated Reports for the 2020 and 2022 will be developed in one listing cycle. The 2020 Integrated Report shall now be referred to as the 2020-2022 Integrated Report but will otherwise be developed in accordance with the 2020 Revised Notice of Solicitation. For the 2020-2022 Integrated Report, the Central Coast, Central Valley, and San Diego Regional Water Boards are “on cycle.” In addition, the Colorado River Basin Regional Water Board conducted an “off-cycle” assessment for one or more waterbodies within their region. For the 2020-2022 Integrated Report, the State Board will be administering the public process. The 2020-2022 Integrated Report is currently in progress.

2018 Integrated Report - Current Integrated Report

The 2018 Integrated Report has been approved by U.S. EPA.

Previous Reports

2012 Integrated Report

2012 Integrated Report (CWA Section 303(d) List / 305(b) Report)
On July 30, 2015, the U.S. EPA issued its final decision regarding the waterbodies and pollutants added to California's 303(d) List. This replaces the 2010 California Clean Water Act section 303(d) List as California's current 303(d) List.

2010 Integrated Report

2010 Integrated Report (CWA Section 303(d) List / 305(b) Report)
On October 11, 2011, the U.S.EPA issued its final decision regarding the water bodies and pollutants added to California's 303(d) List. This replaces the 2006 California Clean Water Act 303(d) List as California's current 303(d) List.

Previous 303(d) Lists and 305(b) Reports
The 2010 Integrated Report is the first Integrated Report developed for the State of California. Previous assessments were developed by the State Water Board in separate documents and can be found at the following links:

Previous Clean Water Act Section 303(d) Lists


Previous Clean Water Act Section 305(b) Reports


Earlier 305(b) Reports are not available in digital format. These reports can be requested through the Public Records Center