Weiser River Subbasin

Subbasin at a Glance

Hydrologic Unit Code	17050124
Size	1,079,148 acres
§303(d) Listed Stream Segments	Weiser River (3 segments), West Fork Weiser River, Mann Creek, Cove Creek, Crane Creek, Little Weiser River, Johnson Creek, North Crane Creek, South Crane Creek, Crane Creek Reservoir
Beneficial Uses Affected	Cold water aquatic life, salmonid spawning, primary/secondary contact recreation, drinking water supply, special resource water, wildlife, aesthetics
Pollutants of Concern	Nutrients, sediment, bacteria, dissolved oxygen, temperature, flow alteration
Major Land Uses	Dryland and irrigated agriculture, range, forest, riparian, open water
Date Approved by U.S. EPA	January 2007

Overview

The Weiser River Watershed encompasses a large area in southwestern Idaho. The headwaters for the Weiser River originate in the southern end of the Seven Devil Mountain Range and the west central mountains of Idaho. A majority of the population in the watershed is associated with small homesteads. The municipalities of Weiser, Midvale, Cambridge, and Council are the only recognized urban areas in the watershed.

Overall, there are 12 §303(d) listed stream segments within the Weiser River Watershed. Eight stream segments were determined not to be supporting their beneficial uses and/or exceeded water quality criteria and had TMDLs developed for them (including temperature TMDLs prepared in the addendum). Two segments were determined to be intermittent water bodies and did not receive TMDLs. One was determined to be fully supporting its beneficial uses and also did not receive a TMDL. Action on Crane Creek Reservoir will be deferred until 2007 to allow further study and to assess the status and appropriateness of its designated uses.

Total maximum daily loads were developed to address sediment, bacteria, and temperature in the Weiser River Watershed. Additionally, total phosphorus load allocations have been established based on load allocations set in the Snake River-Hells Canyon Subbasin Assessment and Total Maximum Daily Loads.

Streams and Pollutants for Which TMDLs Were Developed

Weiser River, Galloway Dam to mouth (at Snake River): Sediment, bacteria, total phosphorus
Weiser River, Little Weiser River to Galloway Dam: Sediment, total phosphorus
Crane Creek: Sediment, bacteria, total phosphorus
Little Weiser River: Bacteria, sediment, total phosphorus

TMDLs Developed in Addendum

Weiser River, Galloway Dam to mouth (at Snake River): Temperature
Weiser River, Little Weiser River to Galloway Dam: Temperature
Weiser River, West Fork Weiser River to Little Weiser River: Temperature
Mann Creek, Mann Creek Reservoir to Weiser River: Temperature
Crane Creek, Crane Creek Reservoir to Weiser River: Temperature
Little Weiser River, Indian Valley to Weiser River: Temperature
West Fork Weiser River, headwaters to Weiser River: Temperature
North Crane Creek, headwaters to Crane Creek Reservoir: Temperature

Subbasin Documents

Weiser River Watershed Subbasin Assessment and Total Maximum Daily Loads (July 2006)
Implementation Plan for Agriculture (December 2008)
Weiser River Total Phosphorus Allocations Addendum to the Snake River-Hells Canyon TMDL (Draft October 2007)
Weiser River Subbasin Temperature Total Maximum Daily Loads: Addendum to the Weiser River Subbasin Assessment and TMDL
(June 2006)

Department of
Environmental Quality

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