DRA Releases 2018 Lower Deschutes River Water Quality Report

The Deschutes River Alliance accomplished a lot of important work for the lower Deschutes River in 2018:

None of this work would have been possible without the generous support and dedication to the lower Deschutes River of our donors.

Photo by Wesley Noone.

 

In addition, we are pleased to announce the release of the DRA’s 2018 Lower Deschutes River Water Quality Report. The report is a comprehensive analysis of data collected from our water quality monitoring work conducted in 2018. This monitoring continues to be an important element in our science efforts and provides invaluable insight into changes occurring on the lower Deschutes River.

What did we find? Once again, our data (in combination with our data we’ll be publishing soon on Lake Billy Chinook) finds the following:

  • Water quality in the surface water in the forebay of Lake Billy Chinook is composed of water matching Crooked River water. This seasonally warm, algae laden and nutrient polluted water forms the surface water that is drawn into the Selective Water Withdrawal (SWW) Tower and, for much of the year, is being discharged undiluted into the lower Deschutes River. Prior to surface water withdrawal, reservoir algae absorbed and utilized the excess nutrients entering the reservoir from the Crooked River.  Then later in the year, the reservoir would mix, or “turn over.”  Back then, cool, clean water was discharged from the bottom of the forebay at Round Butte Dam. Now with surface water draw at the tower, the residency time of surface water is reduced, resulting in nitrogenous nutrients being transferred to the lower Deschutes River.
  • The consequence of this surface water withdrawal is a yearly seasonal pattern of exceeding or not meeting the water quality requirements of the Water Quality Management and Monitoring Plan of the Clean Water Act Section 401 Certification of the Pelton-Round Butte Hydroelectric Complex. The exceedances are primarily for pH and temperature.
  • Dissolved oxygen is not being managed for redband trout during much of their spawning period in the lower Deschutes River.
  • Oregon Department of Environmental Quality pH data collected at the Hwy. 26 bridge on the lower Deschutes River continues to record significantly higher pH (a marker of increased nutrient pollution and algae growth) since the SSW Tower went into operation.
  • In 2018, a reduction in observed turbidity, and increased adult aquatic insect hatch activity during the month of May coincided with reduced Upper Crooked River flows.The upper Crooked River went dry just above the reservoir in mid-May of 2018.

 

These findings are detailed and substantiated in our annual water quality report.

Absent effective action by state and federal authorities, DRA will continue to seek to enforce Clean Water Act water quality standards as a principle means of restoring the ecological integrity of the Lower Deschutes River.

Going forward, we are also implementing a water quality monitoring program for the Crooked River.

We are eager to get our Lake Billy Chinook data published later this summer.  Watch for it in mid-July to early August 2019.

We want to give our most heartfelt thanks to our supporters for making it possible to do this work in monitoring and defending the lower Deschutes River.

 

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