Clark Fork - Pend Oreille Subbasin - Idaho Department of Environmental Quality

Clark Fork - Pend Oreille Subbasin

Subbasin at a Glance

Hydrologic Unit Codes	17010213 and 17010214
Size	25,000 square miles (in Idaho and Montana)
§303(d) Listed Stream Segments	Lake Pend Oreille, Granite Creek, Gold Creek, Pack River, Caribou Creek, Grouse Creek, North Fork Grouse Creek, Trestle Creek, Pend Oreille River, Cocolalla Lake, Cocolalla Creek, Fish Creek, Hoodoo Creek, Clark Fork River, Lightning Creek, East Fork Lightning Creek, Rattle Creek, Wellington Creek, Porcupine Creek, Spring Creek, Twin Creek, Johnson Creek*
Beneficial Uses Affected	Cold water biota, salmonid spawning, warm water biota, primary contact recreation, secondary contact recreation, agricultural water supply, industrial water supply, domestic water supply
Pollutants of Concern	Sediment, dissolved oxygen, nutrients, flow, habitat alteration, metals, pathogens, pesticides, thermal modification
Major Land Uses	Agriculture, grazing, roads, hydropower, mining, timber harvest, urban
Dates Approved by U.S. EPA	April 2001 EPA Approval Letter September 2000 EPA Approval Letter
Date Temperature TMDL Addendum Approved by U.S. EPA	April 2008 EPA Approval Letter
Date Sediment TMDL Addendum Approved by U.S. EPA	January 2008 EPA Approval Letter
Date Pack River Nutrients TMDL Addendum Approved by U.S. EPA	December 2008 EPA Approval Letter

* These water bodies are located in the Clark Fork Subbasin (17010213). They are analyzed in the Clark Fork/Pend Oreille Subbasin Assessment document and are assigned TMDLs in the Lower Clark Fork River Subbasin Assessment and Total Maximum Daily Loads developed in 2007.

Overview

The Clark Fork-Pend Oreille subbasin lies in western Montana, northern Idaho, and northwestern Washington. The subbasin is the source of the water that enters and leaves Lake Pend Oreille, the largest and deepest natural lake in Idaho. Inflow and outflow of the lake are regulated by hydroelectric facilities.

The Pend Oreille portion of this subbasin assessment examined 11 streams, one major river, and two lakes. Of the 11 streams, five were water quality impaired and required load allocations, primarily for sediment. Both Lake Pend Oreille and the Pend Oreille River were found to fully support their beneficial uses and were recommended for delisting.

The Clark Fork portion of this subbasin assessment was tabled until its scheduled due date in 2004. Insufficient time to complete the assessment and the prospect of more data available at that time drove this decision.

Streams and Pollutants for Which TMDLs Were Developed

Cocolalla Creek (lower): Sediment
Cocolalla Creek (upper): Sediment
N. Fork Grouse Creek: Sediment
Hoodoo Creek: Sediment
Pack River: Sediment
Cocolalla Lake: Phosphorus

Subbasin Documents

Clark Fork/Pend Oreille Sub-Basin Assessment and Total Maximum Daily Loads (March 2001)
Pack River Total Maximum Daily Load Implementation Plan for Agriculture (July 2006)
Pack River Watershed Management Plan and TMDL Implementation Plan (July 2006)
Cocolalla Lake, Cocolalla Creek, and Hoodoo Creek Implementation Plan (July 2004)
Pack River Nutrients Total Maximum Daily Load Addendum to the Pend Oreille Lake Nearshore Waters Nutrient SBA and TMDL (November 2007)
Pend Oreille Lake Tributaries Temperature Total Maximum Daily Loads: Addendum to the Pend Oreille Lake Subbasin Assessment and TMDL (November 2007)
Pend Oreille Tributaries Sediment Total Maximum Daily Loads (December 2007)

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