Coeur d'Alene River, South Fork Subbasin

Subbasin at a Glance

Hydrologic Unit Code	17010302
Size	298 square miles (190,765 acres)
§303(d) Listed Stream Segments	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
Beneficial Uses Affected	Cold water, salmonid spawning, primary or secondary recreation
Pollutants of Concern	Sediment, metals (cadmium, lead, zinc)
Major Land Uses	Forestry, mining, urban-suburban
Date Approved by U.S. EPA	August 2003 EPA Approval Letter

Overview

The South Fork Coeur d'Alene River watershed is in the center of the Coeur d'Alene Mining District. Most streams in the subbasin are §303(d) listed for metals and sediment, and one stream is listed for habitat alteration. The trace (heavy) metals impacts to water quality were addressed in the Coeur d'Alene Basin Metals TMDL. (In 2003 the Idaho Supreme Court determined that the Coeur d'Alene Basin Metals TMDL was void because it was not promulgated according to the rulemaking requirements of the state Administrative Procedures Act).

Sediment is listed as a pollutant for 14 stream segments in the watershed. Sediment has its source in mine waste piles, urban land use, road erosion, encroachment on stream channels and floodplains, and encroachment of towns and mining facilities. Impairment of the cold water use has been demonstrated in the low diversity of macroinvertebrates and in low trout abundance. These impacts are the result of both metals and sediment. Impacts of the two pollutants are not easily differentiated. However, the impaired segments of the South Fork Coeur d'Alene River Subbasin typically have low residual pool volumes as compared to segments with high trout abundance. These data indicate sediment is filling pools. Therefore, a sediment TMDL was developed for all of the sediment listed segments of the South Fork Coeur d'Alene River Subbasin.

Canyon Creek is listed for habitat alteration as well as sediment. The U.S. Environmental Protection Agency considers certain unnatural conditions, such as habitat alteration, that are not the result of the discharge of specific pollutants as "pollution." Since TMDLs are not required for water bodies impaired by pollution, but not specific pollutants, a TMDL for habitat alteration was not developed.

Streams and Pollutants for Which TMDLs Were Developed

S. Fork Coeur d'Alene River (6 segments): Sediment
Canyon Creek: Sediment
Ninemile Creek: Sediment
East Fork Ninemile Creek: Sediment
Government Gulch: Sediment
East Fork Pine Creek (2 segments): Sediment
Pine Creek: Sediment

Subbasin Document

South Fork Coeur d’Alene River Sediment Subbasin Assessment and Total Maximum Daily Load (May 2002)

Department of
Environmental Quality

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