| Data | Details |
|---|---|
| Hydrologic Unit Codes | 17060203 |
| Size | 1,810 square miles (1,158,400 acres) |
| Water Bodies with EPA-Approved TMDLs (Category 4a) | Williams Lake |
| Beneficial Uses Affected | Cold water aquatic life, salmonid spawning, recreation |
| Major Land Uses | Agriculture, mining, recreation |
| Date Approved by EPA | April 2013 EPA Approval Letter |
Subbasin Characteristics
The Middle Salmon River-Panther Creek subbasin is located in east-central Idaho on the Idaho-Montana border. The northern part of the subbasin is bounded by the continental divide. The southern boundary of the subbasin ends at the town of Ellis located north of the city of Challis. A small portion of the Frank Church-River of No Return Wilderness is in the northwest corner of the subbasin.
2001 Subbasin Assessment and TMDL
Eight water bodies were listed on the 1998 §303(d) list. This document provides a TMDL for one of these eight. A TMDL was not developed for Diamond Creek because it has an intermittent flow of less than 1 cubic foot per second in the listed segment. Numeric water quality criteria do not apply to streams with less than 1 cubic foot per second flow. Diamond Creek will be monitored further to determine its support status at lower elevations where it is not intermittent. If necessary, a TMDL for Diamond Creek will be developed in 2006.
Metals and pH contamination in four streams associated with Blackbird Mine are well documented, and clean-up activities are underway to restore the water quality and beneficial uses of Panther Creek and Big Deer Creek. These activities will also likely reduce metals contamination in Bucktail and Blackbird Creeks. Since restoration activities have already been planned and implemented for the mine, developing TMDLs for these waters would be a duplication of effort, so TMDLs were not developed for these four creeks.
The US Forest Service has implemented best management practices on Dump Creek. Significant water quality improvements have been noted, and sediment has already been greatly reduced. Since best management practices have already been fully implemented, a TMDL was not developed for Dump Creek.
The Salmon River was identified as an impaired water body on the 1998 §303(d) list, but no pollutants were identified. Information regarding pollution in the Salmon River is very sparse and no water quality problems were identified in this assessment; therefore, a TMDL was not completed for the Salmon River.
A TMDL was developed for Williams Lake for phosphorus. Most of the phosphorus is from nonpoint sources in the Lake Creek watershed, from septic systems associated with recreational residences around the lake, and from a campground on Williams Lake.
2001 TMDL: Stream and Pollutant for Which TMDLs Were Developed
| Stream | Pollutants |
|---|---|
| Williams Lake | Phosphorus |