Water Quality Improvement Project
Naches River Area:
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. (Study
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 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 streams that are
impaired because the water is too hot, for bulltrout 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 total maximum daily load (TMDL), which was
published as Volume 1: Water Quality Study Findings. Volume 1
recommended specific actions for reducing water temperatures, and was approved
by the federal Environmental Protection Agency
(EPA). The study, combined with the implementation strategy published as Volume
constitutes the water quality improvement report (WQIR) for the Upper Naches River and Cowiche Creek for temperature.
In addition to the Upper Naches and Cowiche Creek Temperature WQIR, a project
will be developed for reducing temperatures in the Tieton River and Naches
Now that EPA has approved the WQIR, Ecology is working with interested citizens
in the watershed on implementing actions. When water quality improvement plans
are completed for all the reaches in the Naches watershed, it is anticipated
that temperatures in Tieton and Naches Rivers and Cowiche Creek will come into
compliance with the state water quality standards.
Unless otherwise specified, the following documents are Ecology publications.
Quality Assurance Project Plan: Naches River Temperature Total Maximum Daily
Upper Naches River Temperature Total Maximum Daily Load: Volume 1: Water
Quality Study Findings
Upper Naches River
and Cowiche Creek Temperature Total Maximum Daily Load: Volume 2: Implementation
Quality Assurance Project Plan: Cowiche Creek Vegetation and Shade Study
Wenatchee National Forest Water Temperature Total Maximum Daily Load:
Technical Report (Ecology publication)
WRIA 38: Naches Watershed Information (Environmental Assessment
Program web site)
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