Total Maximum Daily Load (TMDL) Program

Overview

The Federal Clean Water Act (CWA) gives states the primary responsibility for protecting and restoring surface water quality. The TMDL Program addresses impaired waters of the Region and satisfies Clean Water Act Section 303 and 305 requirements. The TMDL Program resources are a combination of funds from the state's Waste Discharge Permit Fee account and federal TMDL development program.

Water Quality Assessment

TMDL staff evaluate waterbody data to determine if water quality objectives are met or are being exceeded. The assessment is presented in the Integrated Report and identifies impaired waterbodies on the CWA 303(d) list. The Integrated Report also provides information about waterbodies which attain their beneficial uses for the 305(b) report.

• View the Lahontan Water Board Integrated Report website

For more information regarding water quality assessment in California please see the State Board Water Quality Assessment website).

SWAMP role in Water Quality Assessment

The Surface Water Ambient Monitoring Program (SWAMP) was created in response to the need for a comprehensive surface water monitoring and assessment program in California. A robust surface water ambient monitoring program is essential for the Water Boards to achieve their mission. Monitoring and assessment projects provide information about water quality and the attainment of beneficial uses at water body, watershed, regional and statewide scales. The SWAMP monitoring programs provide the information needed by Water Board staff, water managers, the Legislature, and the public to understand and better manage California’s precious water resources.

Addressing Impaired Waters

Placement of waterbodies on the 303(d) list initiates the development of Total Maximum Daily Loads (TMDLs). A TMDL identifies the pollutant source and assigns numeric targets for pollutant reduction that are used to prepare the water quality restoration plans. TMDLs are a means to ensure the attainment of water quality standards in impaired surface water bodies, as required by the Federal Clean Water Act (CWA). In some cases, impairments may be addressed through other means in advance of TMDL development. These opportunities are considered Advance Restoration Plans under USEPA’s Vision for the Clean Water Act Section 303(d) Program.

For more information on TMDLs and the TMDL development process, see (State Board Website).

The TMDL Program Fact Sheet provides more information on the Goals, Accomplishments, and Performance Targets.

If you have questions about the Lahontan Region's 303(d) List or the listed projects below, please contact Daniel Sussman.

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Total Maximum Daily Load Projects

Below are the TMDL development projects that the Lahontan Regional Board is currently working on or has completed. Projects have links to documents or other information available for viewing or downloading.

*In 2022, the Department of the Interior changed the name of this waterbody from Squaw Creek to Washeshu Creek. Past TMDL documents retain the old waterbody name.