Total Maximum Daily Load (TMDL) Program


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.

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, without the need to develop a TMDL. These opportunities are considered TMDL Alternatives. Whether and impairment is addressed through a TMDL or other means, the solution should be consistent with the USEPA’s Long-Term Vision for Assessment, Restoration, and Protection under the Clean Water Act Section 303(d) Program.

The Lahontan TMDL program prioritizes listed water bodies to address consistent with the Guidelines for Prioritizing Listed Water Bodies presented at the July 2015 Lahontan Board Meeting.

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.

Projects in Development


Bishop Creek - Pathogens

West Fork Carson River - Multiple Pollutants

Approved TMDLS and Delistings

Blackwood Creek - Sediment
Bronco Creek - Sediment
  • Adopted by with the Truckee River Sediment TMDL. See Truckee River TMDL for relevant documentation.
Carson and Walker River - Sodium
  • Adopted by Lahontan Region October 2006
Crowley Reservoir - Nutrients
Gray Creek - Sediment
  • Adopted with the Truckee River Sediment TMDL. See Truckee River TMDL for relevant documentation.
Heavenly Valley Creek - Sediment
  • Adopted by Lahontan Region January 2001 and approved September 30, 2002 by USEPA
Hot Springs Canyon Creek - Sedimentation/siltation
  • Delisted in November 2010 by USEPA.

Indian Creek Reservoir - Phosphorous

  • Adopted by Lahontan Region July 2002 and approved in 2003 by USEPA
Lake Tahoe - Clarity
Squaw Creek - Sediment
Truckee River - Sediment
Ward Creek - Sediment

Other / Special

Bodie Creek - Metals
Bridgeport Reservoir - Nutrients
Donner Lake - PCBs
Haiwee Reservoir - Copper
Susan River - Toxicity