Protecting Public Health and the Environment.

Bruneau River Subbasin

Subbasin at a Glance

Hydrologic Unit Code 17050102
Size 3,290 square miles (2,112,600 acres)

Water Bodies with EPA-Approved TMDLs (Category 4a)

Bruneau River, C.J. Strike Reservoir (Bruneau arm), Clover Creek, Jacks Creek, Sugar Valley Wash, Three Creek

Beneficial Uses Affected Cold water aquatic life, warm water biota, salmonid spawning, primary and secondary contact recreation

Major Land Uses

Rangeland, irrigated agriculture
Date Approved by EPA

March 2001
EPA Approval Letter

Date Revised Jacks Creek TMDL Approved by EPA

November 2007
EPA Approval Letter

Subbasin Characteristics

The Bruneau River subbasin is located in southwestern Idaho and northeastern Nevada and encompasses several water sources. The springs, snowpack, and rainfall in the Jarbidge Mountains and Jarbidge Wilderness area are the major water sources for the Jarbidge river system. The Bruneau River system begins in a high desert basin bounded by Coyote Mountain to the east, Mason Mountain to the west, and Lookout Mountain to the south. Desert tributaries, in general, are the final source of water to the Bruneau River subbasin. Most of the tributaries are formed on the plateaus and drop steeply in their final few kilometers before their confluence with the major rivers.

2000 Subbasin Assessment and TMDL

This document describes the 9 water bodies and 19 pollutants listed on the 1998 §303(d) list for this subbasin. Two additional pollutant-water body combinations are also assessed. Sediment is the most common listed pollutant in the subbasin; it was a listed pollutant on all 1998 §303(d)-listed water bodies within the subbasin.

In general, the water quality of the Bruneau River is very good. Limited impacts have occurred in the upstream watersheds. Concentrations of suspended materials are very low throughout the subbasin. However, on a seasonal basis, the Bruneau River and other surface water bodies exceed state water quality standards for excessive nutrients, temperature, and/or other pollutants. The temperature exceedances may be due to the influence of thermal spring waters. These waters form the principle habitat for the endangered Bruneau hot springsnail.

Nutrients are a listed pollutant in the Bruneau River and Jacks Creek segments of the Bruneau River subbasin. In these reaches, it was determined that total phosphorus can be a limiting nutrient and that all nutrients may be in excess of recommendations.

In general, the other listed streams and pollutants in the subbasin were well below any standard or guideline established for the protection of beneficial uses or was dry for all, or a majority of, the year. DEQ determined that three of the listed water bodies should not have been considered water bodies that could support beneficial uses and were therefore listed in error.

Bruneau River, Jacks Creek, Wickahoney Creek, and Hot Creek are listed for flow alteration. The US Environmental Protection Agency does not believe that flow alteration is a pollutant 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 alteration.

Temperature is a minor problem in some segments of the Bruneau River subbasin. However, residents of the Bruneau area consider this to be a natural problem. Additionally, in other areas of the state, bioassessment data conflict with temperature information and water quality standards, likely as a result of the state's water quality standards being derived from an outdated understanding of cold water biota's temperature requirements. DEQ is participating in a regional review of temperature criteria. Following the conclusion of the temperature review, temperature exceedances in the Bruneau River subbasin will be reassessed and, if needed, a temperature TMDL will be completed.

2000 TMDL: Streams and Pollutants for Which TMDLs Were Developed

Bruneau River
Nutrients
Jacks Creek
Nutrients, dissolved oxygen, bacteria, sediment
Three Creek
Sediment
Clover Creek
Bacteria
Sugar Valley Wash
Nutrients, dissolved oxygen, bacteria, sediment

2007 Modification

This document establishes water quality load allocations for sediment, nutrients, and bacteria on Jacks Creek in the Bruneau River subbasin. The receiving water body to Jacks Creek is the C.J. Strike Reservoir reach of the Snake River, which is also §303(d) listed. Consequently, the Jacks Creek TMDL modification is necessary to protect the beneficial uses of the Snake River as part of the Bruneau River TMDL.

In the Bruneau River TMDL, the aquaculture fish hatcheries were originally assigned a wasteload allocation based on a concentration limit that was not possible to meet as warmwater facilities based on EPA’s General Aquaculture Permit (IDG-130000). A final §401 water quality certification was issued by DEQ on October 5, 2007, based on EPA’s proposed final versions (received September 7, 2007) of the permit.

This TMDL modification corrects the inconsistency of the phosphorus concentration target used in the Bruneau River TMDL for the aquaculture facilities versus that used in the General Aquaculture Permit for establishing a technology-based effluent limitation. At the same time, it implements the applicable state water quality standards that are based on the relationship between pollutant sources and instream water quality conditions to meet beneficial uses. This TMDL revision provides consistency between the Bruneau River TMDL and the C.J. Strike TMDL. The Jacks Creek TMDL modification establishes the allowable loadings and quantifiable parameters for Jacks Creek and provides the basis for the state to establish water quality-based controls.

These controls should provide the pollutant reductions necessary for Jacks Creek to meet water quality standards. If water quality standards and beneficial uses are not achieved, the TMDL may require more stringent reductions through implementation of other best management practices or limitations.

Subbasin Documents


Staff Contacts

Water Quality Manager
Kiley Mulholland
DEQ Twin Falls Regional Office
650 Addison Avenue West, Suite 110
Twin Falls, ID 83301
(208) 736-2190
kiley.mulholland@deq.idaho.gov

Related Pages

Frequently Asked Questions about Subbasin Assessments and TMDLs

TMDL Implementation Plans

Table of Subbasin Assessments, TMDLs, Implementation Plans, and Five-Year Reviews