Water Quality Improvement Project
The Teanaway River Basin drains an area of 207 square miles and is located east
of the Cascade crest near the town of Cle Elum, Washington. The Teanaway lies in
the upper reaches of the larger Yakima River watershed. The climate consists of
warm, dry summers and cold, snowy winters. Annual precipitation ranges from 20
inches near the mouth of the Teanaway River (elevation 1800 feet) to 90 inches
in the high mountains (elevation 6000 feet).
Water quality issues
In 1998, the Department of Ecology conducted stream temperature studies at eight
sites in the Teanaway Basin. The resulting
River Basin Temperature Pilot Technical Assessment identifies increased
temperatures as the impairing pollutant to the Teanaway River system.
Why this matters
Water temperature influences what types of organisms can live in a waterbody. 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
What are the main factors that affect stream
- Riparian shade - intercepts incoming
Channel width:depth - greater width exposes
more of stream to solar radiation; affected by sediment load and stream bank
- Stream flow - higher flow
increases velocity and depth, decreases time and proportion water exposed to
What can be done to reduce stream temperatures?
Studies have shown that lack of riparian shade, excessive sediment load, and low
stream flow can increase stream temperature. Land management activities, such as
forest management, grazing, agriculture, and development may affect temperature
adversely where they damage vegetation adjacent to streams, cause excessive
erosion of stream banks, add sediment to streams, reduce instream flow, or
return warmed waters to the stream. Activities that reduce stream temperatures
may include those that provide more shading, increase stream flows, and reduce
What we found in the Teanaway River system regarding stream temperatures
The Teanaway River system represents some of the highest quality streams and
cold-water fish spawning and rearing areas in the Yakima River Basin. In the
summer, maximum daily water temperatures in the Teanaway river system range from
12o C (54oF) near the headwaters to 26o C (79o
F) near the mouth.
Under state standards, temperatures should not exceed 16o C (61o
F) in the upper reaches and 18o C (64o F) in the lower
reaches of the river. When natural conditions exceed these numeric standards,
human activities are not to increase stream temperatures by more than 0.3o
C. Data collected during the summer of 1998 show that, except near the
headwaters, temperatures throughout the basin exceeded state water quality
standards. Summer temperatures in the lower basin exceeded the numeric standard
more than 75% of the time.
Status of the project
EPA approved the TMDL submittal in January 2002. The submittal contained
technical studies, identified implementation measures and monitoring plan.
Ecology, along with a work group made up of local groups and the public,
developed a water quality implementation plan, also known as a detailed
implementation plan. The plan included a strategy on how, when and where
restoration activities will be implemented to improve stream temperatures.
- Evaluated technical studies and potential implementation
- Prioritized any additional studies and implementation
- Coordinated implementation of selected measures.
- Developed a monitoring plan to measure improvement.
Teanaway Temperature Total Maximum Daily Load Submittal Report
Teanaway Temperature Total Maximum Daily Load: Detailed Implementation Plan
Teanaway River Basin Temperature Pilot Technical Assessment
Focus on Teanaway Basin - A plan to improve stream temperatures
Protecting Watersheds in the Teanaway River Basin (Ecology water quality
WRIA 39: Upper Yakima
Watershed Information (Water web site)
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