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Water Quality Improvement Projects (TMDLs)

Water resource inventory area (WRIA) 57, Washington State.

Water Quality Improvement Projects
Spokane River Watershed Projects


The Spokane River flows 111 miles from Lake Coeur d’Alene in Idaho to its confluence with the Columbia River. Major tributaries include the Little Spokane River and Hangman (Latah) Creek. This watershed is made up of forest, agriculture, urban and range lands. Agricultural lands lie primarily in the Lower Spokane, Little Spokane, and Hangman Creek watersheds. The urban land use occurs mainly in the Middle Spokane watershed, due primarily to the location of the city of Spokane.

Water quality issues

The Spokane River and some of its tributaries currently do not meet Washington State’s water quality standards for several parameters. Parameters of concern include dissolved oxygen; metals; phosphorus; and toxics. Along and in the Spokane River the major health concern is the consumption of PCB-contaminated fish.

Spokane River Dam.  Photo courtesy of Robert Ashworth,

 © Robert Ashworth,

Why this matters

The Spokane River is one of the most prominent features in Spokane, Washington. Protecting the river is of great economic importance to the people of Spokane and the surrounding area as its recreational and aesthetic values encourage tourism and create a very desirable place to live. The river also has six dams generating hydroelectric power.

Underneath the river lies the Spokane Valley – Rathdrum Prairie Aquifer, the sole source of drinking water for over 400,000 people in the region. In some places the aquifer discharges into the Spokane River, and in other locations the river discharges into the aquifer. The Spokane Aquifer Joint Board’s web page provides more information about the aquifer.

What is being done

To address these water quality issues the Department of Ecology (Ecology) is establishing water quality improvement projects (also know as a Total Maximum Daily Load or TMDL) in several areas in the watershed. A water quality improvement project is a public process in which local organizations and citizens develop actions designed to reduce pollution and bring a water body back to a healthy condition.

Project information

Dissolved Oxygen TMDL

Dissolved Metals TMDL


Related Information

Surf the watersheds listed below at the Environmental Protection Agency’s (EPA) web site:

Spokane River web site
A "one-stop" page to make it easier to find information about the Spokane River, the many projects and activities taking place and the agencies and organizations involved.

Environmental improvements on the Spokane River (Ecology Publication)

Keeping Pollutants out of Urban Waters (Ecology water quality story)

Turbid Runoff and the Railroad (Ecology water quality story)

Contact us for more information

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