|Hydrologic Unit Code||17010305|
|Size||209 square miles (133,760 acres)|
Water Bodies with EPA-Approved TMDLs (Category 4a)
Fish Creek and tributaries, Hauser Lake, Hayden Lake, Twin Lakes
|Beneficial Uses Affected||Cold water aquatic life, salmonid spawning, primary contact recreation|
|Major Land Uses||Forestry, agriculture, urban|
|Date Approved by EPA||
|Date Addendum Approved by EPA||
The Rathdrum Prairie is a 209-square-mile area located west of the Coeur d’Alene Mountains, north of Coeur d’Alene Lake, and south of Lake Pend Oreille. In addition to the two large lakes, five smaller lakes are located on the fringes of the prairie. The Spokane River traces the southern boundary of the subbasin on its route from Coeur d’Alene Lake to the Washington border.
2022 TMDL Spokane River Metals TMDL
The Spokane River is in the Upper Spokane subbasin in Kootenai County, Idaho, and drains the 4,345 mi2 Couer d’Alene basin. The Spokane River is the only surficial outlet of Coeur d’Alene Lake, flowing from the northern end of the lake 15 miles in Idaho before exiting into Washington. The Spokane River flows westward through the city of Spokane to join the Columbia River 110 miles from the outlet of Coeur d’Alene Lake.
The Spokane River was listed in 1994 for unknown metals in Idaho’s § 303(d). In Idaho’s 2008 Integrated Report, the unknown metals impairment was replaced with cadmium, lead, and zinc. Cadmium was delisted as a cause of Impairment in Idaho’s 2016 Integrated Report.
The 2022 Spokane River Metals TMDLs develop TMDLs for two Spokane River Assessment Units between the Coeur d’Alene Lake outlet and the Washington border. The Spokane River Metals TMDL was developed using numeric criteria for lead and zinc. Wasteload allocations were designed for seven-point source discharges, and load allocations were set for nonpoint sources of metal pollution.
2022 TMDL: Streams and Polutants for Which TMDLs Where Developed
|Spokane River||Lead, Zinc|
2008 Fish Creek Watershed Assessment and TMDL
The Fish Creek watershed is contained within the Upper Spokane River subbasin. It is located northeast of Coeur d’Alene and drains east from across the Idaho/Washington border into the Twin Lakes. Ownership in the watershed is almost entirely private land. The Inland Empire Paper Company, the Idaho Department of Lands, and a few small private landowners are the primary land holders within the watershed. The majority of the stream is forested, intermixed with shrubs, grass meadows, and pastureland near its mouth before draining into upper Twin Lakes.
The Upper Spokane River Subbasin Assessment and Total Maximum Daily Loads developed in 2000 did not directly address excess pollutant loads within the Fish Creek watershed. Therefore, a separate document, entitled Fish Creek Watershed Assessment and Total Maximum Daily Loads, was developed in January 2007 and approved by EPA in June 2008.
2008 TMDL: Stream and Pollutants for Which TMDLs Were Developed
|Fish Creek and tributaries||Sediment, temperature, bacteria|
2000 Subbasin Assessment and TMDL
The Spokane River is listed for temperature, but the assessment found the temperature in the Spokane River is caused by natural conditions and recommends the river be redesignated as limited cold water biota. Nutrient (total phosphorus) TMDLs were developed for Hauser, Hayden, and Twin Lakes. The total phosphorous TMDL developed for the Twin Lakes addresses Fish and Rathdrum Creeks as well.
The dissolved oxygen limitation of Hauser Lake is dependent on total phosphorous reductions. Data indicate that Spirit Lake is meeting the total phosphorus goal and dissolved oxygen standards.
Sediment modeling of Fish and Rathdrum Creeks indicates these water bodies are not limited by sediment. Bacteria standards are also met in Fish and Rathdrum Creeks and in Upper Twin Lake. Metals TMDLs for this subbasin are addressed in a previous TMDL; however, the district judge ruled the TMDL was invalid for failure to comply with statutory guidelines.
2000 TMDL: Streams and Pollutants for Which TMDLs Were Developed
|Hauser Lake||Total phosphorus|
|Hayden Lake||Total phosphorus|
|Lower Twin Lake||Total phosphorus|
|Upper Twin Lake||Total phosphorus|