Blackfoot River Subbasin

Subbasin at a Glance

Hydrologic Unit Code	17040207
Size	1,000 square miles
§303(d) Listed Stream Segments	Blackfoot River (3 segments), Wolverine Creek, Brush Creek, Corral Creek, Grizzly Creek, Meadow Creek, Trail Creek, Slug Creek, Dry Valley Creek, Maybe Canyon Creek, Angus Creek, Lanes Creek, Bacon Creek, Sheep Creek, Diamond Creek
Beneficial Uses Affected	Cold water aquatic life, salmonid spawning
Pollutants of Concern	Sediment, nutrients, flow alteration
Major Land Uses	Dryland and irrigated agriculture, livestock grazing, phosphate mining
Date Approved by U.S. EPA	April 2002 EPA Approval Letter

Overview

The Blackfoot River Subbasin is located in southeast Idaho. Historically, Blackfoot River Subbasin water bodies sustained several beneficial uses. All streams supported cold water aquatic life and agriculture water supply as well as secondary contact recreation. The bigger streams also supported primary contact recreation and most streams maintained spawning populations of salmonids. Domestic water supply has been officially declared a designated use in the Blackfoot River above the reservoir. Current information suggests that some beneficial uses, such as cold water aquatic life and salmonid spawning, are impaired and are not fully supported in several streams in the subbasin.

Sources of pollutant input above natural levels have been identified from various reports. Sediment input has been caused by agricultural and livestock practices, changes in the natural hydrograph, roads, mining activities, and mass wasting (e.g., landslides). Agriculture, grazing, and recreation (human wastes linked to camping areas) have been associated with nutrient input into Blackfoot River Subbasin streams.

TMDLs were developed for sediment and nutrients. The U.S. Environmental Protection Agency considers certain unnatural conditions, including flow alteration, that are not the result of the discharge of a specific pollutants as "pollution." Since a TMDL is not required for a water body impaired by pollution, but not a specific pollutant, a TMDL was not developed for flow alteration.

Streams and Pollutants for Which TMDLs Were Developed

Blackfoot River: Sediment, nutrients
Wolverine Creek: Sediment,nutrients
Jones Creek: Sediment, nutrients
Brush Creek: Sediment
Slug Creek: Sediment
Dry Valley Creek: Sediment
Angus Creek: Sediment
Lanes Creek: Sediment
Diamond Creek: Sediment

Subbasin Documents

Blackfoot River TMDL Waterbody Assessment and Total Maximum Daily Load (December 2001)
Blackfoot River TMDL Implementation Plan (February 2006)
Brush Creek Temperature Total Maximum Daily Load: Addendum to the Blackfoot River Subbasin Assessment and TMDL (November 2007)
Brush Creek TMDL Approval Letter (December 2007)
Blackfoot River Subbasin Assessment and Total Maximum Daily Loads: 2013 Addendum (May 2013)

Department of
Environmental Quality

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