Coeur d'Alene River (South Fork) Subbasin
Subbasin at a Glance
|Hydrologic Unit Code||17010302|
|Size||298 square miles (190,765 acres)|
Water Bodies with EPA-Approved TMDLs (Category 4a)
Canyon Creek, East Fork Pine Creek, Government Gulch, Ninemile Creek, Pine Creek, South Fork Coeur d’Alene River
|Beneficial Uses Affected||Cold water aquatic life, salmonid spawning|
|Major Land Uses||Mining, forestry, recreation, urban-suburban|
|Date Approved by EPA||
The South Fork Coeur d'Alene River and its tributaries drain the entire subbasin represented by hydrologic unit code 17010302. The river and its tributaries flow from the Coeur d'Alene Mountains to the river’s confluence with the North Fork Coeur d'Alene River near Enaville, Idaho. The subbasin encompasses approximately 298 square miles and is a mix of communities, mining and other industrial sites, forests, and landownerships.
Most streams in the South Fork Coeur d’Alene River subbasin are listed as impaired by sediment, metals, or temperature. In 2000, DEQ and EPA developed TMDLs for cadmium, lead, and zinc in the Coeur d’Alene Basin, including the South Fork Coeur d’Alene River and tributaries. In 2003, the Idaho Supreme Court determined that the Coeur d’Alene Basin metals TMDLs were void because they were not promulgated according to the rulemaking requirements of the state Administrative Procedures Act.
2002 Subbasin Assessment and TMDL
Sediment was listed as a pollutant impairing cold water aquatic life for several stream segments in the watershed. Sources of sediment included mine waste piles, urban land use, road erosion, and encroachment on stream channels and floodplains. Impairment of the cold water beneficial use was demonstrated through low diversity of macroinvertebrates and low trout abundance. These impacts were the result of both metals and sediment. Impacts of the two pollutants are not easily differentiated. However, the impaired stream segments in the South Fork Coeur d'Alene River subbasin typically had low residual pool volumes compared to segments with high trout abundance. These data indicate excess sediment was filling pools. Therefore, sediment TMDLs were developed for all of the sediment-impaired stream segments in the South Fork Coeur d'Alene River subbasin.
2002 TMDL: Streams and Pollutants for Which TMDLs Were Developed
- South Fork Coeur d'Alene River (6 segments)
- Canyon Creek
- Ninemile Creek
- East Fork Ninemile Creek
- Government Gulch
- East Fork Pine Creek (2 segments)
- Pine Creek