Salmon River (Upper) Subbasin

Subbasin at a Glance

Hydrologic Unit Code	17060201
Size	2,425 square miles
§303(d) Listed Stream Segments	Salmon River, Challis Creek, Garden Creek, Warm Springs Creek, Thompson Creek, Yankee Fork, Lost Creek, Kinnikinic Creek, Road Creek, Squaw Creek
Beneficial Uses Affected	Domestic water supply, cold water biota, salmonid spawning, primary and secondary contact recreation, special resource water
Pollutants of Concern	Sediment, temperature, nutrients, flow alteration, habitat alteration
Major Land Uses	Forest, irrigated cropland, range, urban
Date Approved by U.S. EPA	March 2003

Overview

The Upper Salmon River Subbasin is located in the central Idaho mountains. The mountainous terrain in this subbasin has produced many steep stream systems and glacial lakes and troughs that feed the headwaters of the Salmon River.

The waters of the Upper Salmon River have been identified as an essential component of anadromous fish and bull trout restoration in Idaho. The Endangered Species Act requires that conservation plans be developed and implemented to restore anadromous fish and bull trout populations to levels that insure their persistence in the Upper Salmon River watershed.

Water quality, native fish populations, and riparian habitat conditions have been issues of concern in the Upper Salmon River Subbasin. The cumulative effects of mining, grazing, over-utilization of riparian areas, timber harvest and associated roads, exotic species, residential and recreational development, and human-caused stream alteration and diversion have combined to limit the production and survival of native resident and anadromous fishes throughout the subbasin.

DEQ has identified Challis Creek as not fully supporting the beneficial uses of salmonid spawning and cold water biota. A TMDL for sediment has been prepared for this water body to restore full support of these beneficial uses. The Challis Creek TMDL should also assist in endangered species recovery.

Streams that already have best management practices in place that should result in attainment of water quality standards and beneficial use support in the near future do not require TMDLs. Streams that fall into this category are Thompson Creek and Kinnikinic Creek.

The two listed reaches of the Salmon River also do not require TMDLs because they fully support beneficial uses. A TMDL was also not prepared for Squaw Creek (listed for temperature), as it was found that the warm temperature in the creek is natural, from geothermal sources.

Streams that have flows less than 1 cubic foot per second are not held to narrative water quality standards. Lost Creek in the upper Stanley Basin is such a creek. It was listed in error and will not have a TMDL developed for it.

Challis Creek, Thompson Creek, and Yankee Fork are listed for flow and/or habitat alteration. It was also found that Garden, Warm Springs, and Road Creeks are impaired by flow alteration. However , the U.S. Environmental Protection Agency does not believe that flow and habitat alteration are pollutants as defined by the Clean Water Act. Since TMDLs are not required for water bodies impaired by pollution but not pollutants, TMDLs were not developed for flow or habitat alteration.

Stream and Pollutant for Which TMDL Was Developed

Challis Creek: Sediment

Subbasin Documents

Upper Salmon River Subbasin Assessment and TMDL (January 2003)
Upper Salmon River Subbasin Total Maximum Daily Load Agricultural Implementation Plan (February 2007)

Department of
Environmental Quality

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