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Water Quality Improvement Projects (TMDLs)

Water resource inventory area (WRIA) 13, Washington State.

Water Quality Improvement Projects
Deschutes River Basin Area


The two water quality improvement projects in this basin cover a 186 square mile area that extends from the headwaters of the Deschutes River northward through Capitol Lake and Budd Inlet. It lies entirely within Water Resource Inventory Area 13 (WRIA 13). Thurston County and Lewis County, the cities of Olympia, Lacey, and Tumwater, and the town of Rainier are all in the basin. Residents rely on groundwater from the Deschutes watershed or the adjacent McAllister Springs for drinking water. Land cover includes a mix of forested lands, agricultural uses, rural, residential, and urban lands. Budd Inlet is the southern tip of Puget Sound, and it is Olympia’s urban waterfront. Recreational boaters and commercial vessels using the Port of Olympia frequent the area. It is also home to abundant aquatic life.

Water quality issues

Portions of the Deschutes River, Percival Creek, other creeks in the area, Capitol Lake, and the marine waters of Budd Inlet do not meet water quality standards for temperature, fecal coliform bacteria, dissolved oxygen, pH, phosphorus, and fine sediment. These waterbodies have low dissolved oxygen levels, high water temperatures, excess sediment, too much phosphorus, and high bacteria levels. These problems are caused by lack of shade over creeks and streams, improperly functioning on-site septic systems, livestock, pets, wildlife, stormwater runoff pollution, discharges of nitrogen, modifications of the river, and other issues, and can be harmful to fish and other aquatic animals.

Waters in this basin are under pressure from growth, resulting in many small, uncontrolled sources of pollution. Local city, county, and state government agencies work hard to monitor and protect the quality of our water. Sampling and analysis of the water revealed poor water quality, therefore triggering the “TMDL” process.

What is being done

Partners in the basin are working to implement the water quality improvement project for the Deschutes River, Percival Creek, and other tributaries that Ecology completed in 2015 ( Ecology is currently working with our partners to develop a second water quality improvement project to address low dissolved oxygen levels in Budd Inlet.

Deschutes River, Washington State.  Photographer Andrew Kolosseus, WA State Department of Ecology.


Project information

Water-body Name Parameter(s)
Deschutes River, Percival Creek, and Budd Inlet Tributaries Dissolved Oxygen, Fecal Coliform Bacteria, Fine Sediments, pH, Temperature
Budd Inlet Dissolved Oxygen


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Last updated March 2017