Water Quality Improvement Projects (TMDLs) > Yakima Watershed Area Projects > Naches River Area Temperature Project

Water Quality Improvement Project
Naches River Area:
Temperature

Introduction

The Naches River watershed, located in part of the Yakima River drainage basin, flows from the Cascade mountains to the city of Yakima.  It then merges with the Yakima River. Some of the river's tributaries of interest include the American River; Bear Creek; Blowout Creek; Bumping River; Cowiche Creek; Crow Creek; Gold Creek; Little Naches River; Little Rattlesnake Creek; Mathew Creek; Nile Creek; Rattlesnake Creek; and Reynolds Creek.

The climate in the Naches River watershed  is generally cool and moist in the mountainous portion, and warm and dry in the valley.  Precipitation ranges from 80 - 140 inches in the mountains to less than 10 inches in the valley portion. The Naches River is used as core summer habitat and spawning by a number of salmonid species, including Spring Chinook salmon, rainbow/steelhead trout, and bull trout.

Water quality issues

Studies determined that the Naches River does not meet state water quality standards for temperature in a number of places.  The Naches River, along with a number of tributaries, was listed on the 2004 and 2008 water quality assessments in category 5 (also known as the 303[d] list), for exceeding temperature criteria protective of char spawning and rearing; core summer salmonid habitat; and salmonid spawning, rearing, and migration.

Why this matters

Water temperature influences what types of organisms can live in a water body. Cooler water can hold more dissolved oxygen that fish and other aquatic life need to breathe. Warmer water holds less dissolved oxygen. Threatened and endangered salmon need cold, clean water to survive.

The watershed community can cool water temperatures by shading the water with streamside vegetation. Land use practices that reduce or slow water runoff can also help water temperatures by stabilizing water flow in the river system.

Status of the project

In 2008 Ecology completed the technical study of Naches River and tributaries. Ecology and interested citizens in the watershed then developed a draft implementation strategy, which was available for public review and comment from October 20 - November 19, 2010. No public comments were received.

Ecology sent the finalized WQIR to the federal Environmental Protection Agency (EPA) for approval. EPA approved the TMDL within the WQIR on January 28, 2011. The study, combined with the implementation strategy, constitutes the WQIR for the Naches River and Cowiche Creek for temperature.

Now that EPA has approved the WQIR Ecology, again working with interested citizens in the watershed, will develop an implementation plan. The plan will build on the strategy started in the WQIR, providing  more detail on what needs to be done and what will be done to help bring the Naches River and Cowiche Creek into compliance with the state water quality standards for temperature.

Technical information

Quality Assurance Project Plan: Naches River Temperature Total Maximum Daily Load (Ecology publication)
www.ecy.wa.gov/biblio/0403110.html

Upper Naches River Temperature Total Maximum Daily Load: Volume 1: Water Quality Study Findings (Ecology publication)
www.ecy.wa.gov/biblio/0803036.html

Upper Naches River Temperature Total Maximum Daily Load: Volume 2: Implementation Strategy (Ecology publication)
www.ecy.wa.gov/biblio/1010068.html

Wenatchee National Forest Water Temperature Total Maximum Daily Load: Technical Report (Ecology publication)
www.ecy.wa.gov/biblio/0310063.html

Related information

WRIA 38: Naches Watershed Information (Environmental Assessment Program web site)
www.ecy.wa.gov/apps/watersheds/wriapages/38.html

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