Since 2010, when a “Selective Water Withdrawal” tower came online at the Pelton-Round Butte Hydroelectric Project, the ecology of the lower Deschutes River has changed dramatically. Research and analysis, along with observations from longtime river users, has brought three core issues to the forefront of our work:

 

Water Quality

Discharges from the Pelton-Round Butte Hydroelectric Project are regularly violating state water quality standards for pH and dissolved oxygen, as well as temperature requirements in the Project’s Clean Water Act certification. We believe it is critical that dam operators come into compliance with these standards and requirements, which were developed and implemented to protect aquatic life in the lower Deschutes River.

Learn more about water quality issues in the DRA Science Team's Water Quality Reports.

Read about the DRA's lawsuit to enforce water quality requirements at the Pelton Round Butte Project.


Nutrients and Nuisance Algae 

Increased nutrient loads in the lower river, directly related to the discharge of surface water from Lake Billy Chinook, are causing major ecological changes below the dams. These changes include a dramatic increase in nuisance algae, a shift in the aquatic insect community toward a community more dominated by snails and worms, and increased reports of "Black Spot Disease" in redband trout, bull trout, and steelhead. These are all classic ecological shifts due to nutrient enrichment.

Read more about nutrient enrichment in the DRA's Water Quality Reports.

 


Aquatic Insects

Long-time river users have reported dramatic shifts in aquatic insect populations and hatch timing since the SWW tower operations began. This has significantly impacted the angling experience on the lower river, and continues to affect birds, bats, and other insectivorous species below the dams.

Read more about lower Deschutes River aquatic insect populations in the DRA's annual Macroinvertebrate Hatch Surveys.