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Water Quality Improvement Projects (TMDLs)

Water resource inventory area (WRIA) 45, Washington State.

Water Quality Improvement Projects
Wenatchee River Basin Area


The Wenatchee River originates at Lake Wenatchee and drains an area of about 1,371 square miles. It flows through the communities of Plain, Leavenworth, Peshastin, Dryden, and Cashmere, and meets the Columbia River at the city of Wenatchee. Annual average precipitation ranges from 150 inches at the crest of the Cascades to 8.5 inches in Wenatchee.

Rivers, lakes, and streams in the Wenatchee watershed are used by people in many ways, from forestry, agricultural, municipal, and business needs to recreational enjoyment and drinking water. These water bodies are also important spawning and rearing areas for many salmonid species, as well as other wildlife.

Water quality issues

Pollution threatens the health of the watershed and jeopardizes its many uses. Water in the Wenatchee watershed has been listed on Washington State's 303(d) list for dissolved oxygen and pH. Other water quality issues include DDT, fecal coliform bacteria, and high water temperatures.

Why this matters

The Wenatchee River is part of a sensitive ecosystem which its citizens work hard to protect. Besides business and recreational needs, the water bodies in this system are also important spawning and rearing areas for many salmonid species and other wildlife.

What is being done

The Wenatchee River basin has tremendous participation and stewardship by its citizens. Ecology, in cooperation with local stakeholders and citizens, is seeking to address water quality issues in the Wenatchee River watershed through the development and implementation of water quality improvement projects, also known as total maximum daily loads (TMDLs).

Project information

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Last updated December 2015