We are thrilled to announce the publication of the DRA’s 2016 Lower Deschutes River Water Quality Report. This report—along with three other reports we’ll be releasing over the next two months—is the culmination of the DRA’s most detailed investigation yet of the causes and extent of the ecological changes occurring in the lower Deschutes River.
An important aspect of the report analyzes hourly water quality data collected at River Mile 99, one mile below the Pelton Reregulating Dam, from February 18 through November 22, 2016. All data collected for pH, temperature, and dissolved oxygen are presented and analyzed, and compared against water quality requirements contained in the state-issued Clean Water Act § 401 Certification for the Pelton-Round Butte Complex, as well as Oregon’s water quality standards for the Deschutes Basin. Read the whole thing here.
This report represents the most complete public analysis yet of the impact of Selective Water Withdrawal operations on water quality below the Pelton-Round Butte Hydroelectric Complex. Key findings include:
- Oregon’s water quality standard for pH in the Deschutes Basin (6.5-8.5 SU) was exceeded on 234 out of 279 days that data were collected (84%). 43% of the days sampled had pH measurements greater than 9.0.
- Each year since 2011, Project operators have worked with the Oregon Department of Environmental Quality to purportedly weaken the water quality requirements in the Project’s Clean Water Act § 401 Certification. These changes include:
- The defined spawning season for salmonids was changed from year-round to Oct. 15-June 15. This change allows the application of a lower dissolved oxygen standard during the non-spawning period (June 16-Oct. 14). However, this newly defined spawning period does not take into account the full season of resident trout spawning and egg incubation, as is required by the Oregon Administrative Rules. This has caused dissolved oxygen levels in the lower Deschutes River to fall below levels required to protect resident salmonids through egg incubation and fry emergence.
- The water temperature that triggers the blending of cool bottom water from Lake Billy Chinook with warmer surface water has been markedly increased since the Selective Water Withdrawal tower began operations. This has allowed the release of 100% surface water into the lower Deschutes River to continue later into the summer.
- Changes in pH and dissolved oxygen, documented by this study and ODEQ’s own data, clearly indicate that excess nutrients are being released into the lower Deschutes River from the surface waters of Lake Billy Chinook.
DRA’s 2016 Lower Deschutes River Water Quality Report clearly establishes that, in just seven years of operation, the Selective Water Withdrawal tower at Pelton-Round Butte has severely degraded water quality and threatens aquatic life below the Project. We believe this report will serve as an important document for all basin stakeholders in assessing the impact of tower operations on the river we all love.
A special thanks to all of our supporters, whose generosity and passion for the river has made all of our science work possible. We’d like to take this opportunity to specifically thank the various organizations and foundations who have provided funding to support this critical work, including:
- The Oregon Wildlife Heritage Fund
- Maybelle Clark MacDonald Fund
- Flyfishers Club of Oregon/Flyfishers Foundation
- Clark-Skamania Flyfishers
- American Fly Fishing Trade Association
- Tualatin Valley Chapter of Trout Unlimited
- Washington County Fly Fishers
Cooler, cleaner H2O for the Deschutes!
Deschutes River Alliance: Cooler, cleaner H2O for the lower Deschutes River.
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