The majority of the Beaverhead TMDL Planning Area (TPA) is located within Beaverhead County, with a small portion in Madison County and includes the towns of Dillon and Twin Bridges. The Beaverhead TPA encompasses the Beaverhead River watershed, which begins at the outlet of the Clark Canyon Reservoir and flows northeast 79.5 miles before joining the Big Hole River to form the Jefferson River. The TPA coincides with the 10020002 fourth-code hydrologic unit code (HUC), and is bounded by the Pioneer Mountains on the west, the Ruby Range to the east, and the Snowcrest Range and Blacktail Mountains to the south.

The Montana Department of Environmental Quality has identified 16 streams with water quality impairments in the Beaverhead TPA. They are shown in the table below. Impairments include sediment, temperature, nutrients, and metals. The TMDL planning process for this TPA incorporates a combination of water quality sampling and hydrologic modeling to further identify and quantify sediment, temperature, nutrient, and metal contributions from all significant sources.

The table identifies which streams have sediment, temperature, nutrient and/or metals listed impairments. For complete information on each stream's probable impairment causes and sources, see DEQ's Clean Water Act Information Center. To view the most recent information, click on "Begin Search" and then select "Beaverhead" in the TMDL Planning Area drop-down list under "Step 2." You do not need to select anything else in Step 1 or Step 2.

Sediment and temperature TMDLs are currently under development in the planning area and are projected to be complete in 2011. The nutrient and metal TMDLs are scheduled for completion approximately 2012.  The DEQ has completed several years of water quality sampling for sediment, temperature, nutrients, and metals in cooperation with the Beaverhead Watershed Committee and others, primarily in 2003/2004 and 2008/2009. Additional assessment work for sediment was completed in September 2010 and April 2011. A complete project schedule will be posted in the near future.