San Diego Region - Clean Water Act Section 305(b) Surface Water Quality Assessment and Section 303(d) List of Water Quality Limited Segments (updated 11-04-16)

The federal Clean Water Act (CWA) requires States to identify and make a list of surface water bodies that are polluted. These water bodies, referred to in law as "water quality limited segments," do not meet water quality standards even after discharges of wastes from point sources have been treated by the minimum required levels of pollution control technology. Wastewater treatment plants, a city's storm drain system, or a boat yard are a few examples of point sources that discharge wastes to surface waters. States are required to compile these water bodies into a list, referred to as the "Clean Water Act Section 303(d) List of Water Quality Limited Segments" (List). States must also prioritize the water bodies on the list and develop Total Maximum Daily Loads (TMDLs) to improve the water quality.

The "Water Quality Control Policy for Developing California's Clean Water Act Section 303(d) List" is the policy for the State and Regional Water Boards to follow when developing updates to the List. This policy describes the process by which the State and Regional Water Boards comply with the requirements of the Clean Water Act in developing the List.

2018 "Off-cycle" Water Quality Assessment 305(b) Update: Public Meeting and Opportunity to Comment

The San Diego Water Board is proposing updates to the CWA 305(b) Report as a result of "off-cycle" assessments of readily-available biological data.

Public Meeting: 9:00 a.m. Wednesday, February 12, 2020

2014 Water Quality Assessment and 303(d) List Update

State Board approved the 2014 303(d) List on October 3, 2017, by Resolution No. 2017-0059, and on April 6, 2018, USEPA approved the List.

2012 Water Quality Assessment and 303(d) List Update

The State Water Board initiated the solicitation period on January 14, 2010 to request from interested persons data and information regarding water quality conditions in surface waters of California. Information gathered will be used to provide the basis both for assessing overall surface water quality conditions in California and identifying and listing impaired waters that are not meeting water quality standards. The solicitation period was closed on August 30, 2010 and the water quality assessment is currently underway.

If you would like to be on our mailing list for the 2012 List Update, please subscribe to our mailing list. Be sure to select the "Section 303d List" option under Mailing List.

Approved 2008-2010 303(d) List

The San Diego Water Board adopted the 2008 Clean Water Act Sections 305(b) and 303(d) Integrated Report on Evaluation of Surface Water Quality and Listing of Impaired Water Body Segments for the San Diego Region (2008 Integrated Report) on December 16, 2009. The final 2008 Integrated Report was incorporated into the statewide 2010 Integrated Report that was approved by the State Water Board on August 4, 2010. On November 12, 2010, USEPA approved the 2008-2010 CWA Section 303(d) List that includes listings for the San Diego Region. More information , including the 2010 Integrated Report and interactive map of all assessed waters in California, can be found on the State Water Board webpage.

Clean Water Act Sections 305(b) and 303(d) 2008 Integrated Report for the San Diego Region

Approved 2006 List of Water Quality Limited Segments

On June 28, 2007 the U.S. Environmental Protection Agency gave final approval to California's 2006 Section 303(d) List of Water Quality Limited Segments.

The links below provide information on the 2006 List for the San Diego Region.

Other Links

  • USEPA has a web page which provides information on current activities associated with the Section 303(d) listing and Section 305(b) assessment processes. The Consolidated Assessment and Listing Methodology (CALM) initiative is currently being developed and addresses identification of impaired waters under Section 303(d) and preparation of water quality assessment reports under Section 305(b) of the Clean Water Act.
  • USEPA Region IX's web page includes information on monitoring, assessment (including List updates), and TMDL programs for Arizona, California, Hawaii, Nevada, the Pacific Islands subject to U.S. law, and approximately 140 Tribal Nations.