Deschutes River, Percival Creek, & Budd Inlet tributaries

Water quality issues

The Deschutes River is under pressure from growth, resulting in many small, uncontrolled sources of pollution that enter the river. Local city, county, and state government agencies monitor and protect water quality. In the Deschutes, water quality monitoring revealed that levels of pH, dissolved oxygen, temperature, fine sediment, and fecal coliform did not meet state standards. We began the TMDL process to address these problems.

What is being done

With the help of an advisory group of affected stakeholders, special interest groups, and interested residents, we developed a TMDL plan to solve the river's pollution problems. The Deschutes River, Percival Creek, and Budd Inlet Tributaries Water Quality Improvement Plan (also known as a TMDL) assigns the amount of pollution the water bodies can receive and still meet water quality standards. Any additional amount needs to be eliminated to achieve clean water.

This plan provides a framework for how stakeholders will track, monitor, and implement the water cleanup plan. It outlines what is needed, establishes a schedule, and guides corrective actions with adaptive management practices.

We gathered public comments on the draft plan in 2015. We held two public meetings to provide a broad overview of the project and findings. In 2018, EPA approved some elements of the TMDL plan and disapproved others. See our 2018 Letter to Stakeholders for details. 

On August 10, 2020, EPA finalized the replacement of the TMDL elements that were disapproved. They are open for public comment until October 7, 2020 and can be found on EPA's Deschutes River TMDLs web page.

Why this matters

Water must be of high quality to support fish and wildlife.

Dissolved oxygen — oxygen dissolved in healthy water — is vital for the survival of fish and aquatic life. It is more difficult to transfer oxygen from water to blood than it is to transfer oxygen from air to blood. Therefore, it is critical that an adequate amount of oxygen is maintained in the water for this transfer to take place efficiently and sustain aquatic life. Oxygen is also necessary to help decompose organic matter in the water and bottom sediments as well as for other biological and chemical processes.

Fecal coliform is a type of bacteria common in human and animal waste. It can make people sick and cause the closure of shellfish harvesting beds. Bacteria can get into waters from untreated or partially treated discharges from wastewater treatment plants, from improperly functioning septic systems, and from livestock, pets, and wildlife.

People can help keep bacteria out of the water. Properly collect, bag, and trash dog poop. Check your on-site sewage system to make sure it is maintained and working properly. Use proper storage, management, and disposal practices for livestock manure.

pH is a measure of the acidity or alkalinity of the water. pH can affect the solubility of nutrients and metal compounds. By affecting the solubility of nutrients, it can change the amount of nutrients available for plant growth. If too many nutrients are available, aquatic plants can grow out of control. When these plants decompose, they can deplete the water of oxygen. The solubility of many metal compounds also changes greatly with pH. When more metals are dissolved in the water, aquatic animals may absorb them faster. Therefore, a lower pH may make these metals more toxic to aquatic life.

Water temperature influences what types of organisms can live in a water body. Cooler water holds 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. Removing streamside vegetation tends to raise water temperature to a level that may be harmful to fish, other aquatic animals, and insects.

Finally, too much sediment in the water can irritate fish gills and make it difficult for them to breathe.