Corps Releases Draft EIS For 13 Willamette Basin Dams Intended To Aid ESA-Listed Salmon, Steelhead; Drawdowns, Structural Changes, Less Power
Operations at thirteen federal dams in the Willamette River basin may soon be altered to aid threatened upper Willamette River spring Chinook, winter steelhead, and bull trout. The U.S. Army Corps of Engineers, which operates the dams, released a draft operations and maintenance programmatic environmental impact statement late last week for public review until January 19, 2023.
The draft’s preferred alternative – Alternative 5 – is the fourth costly of the alternatives. It uses improved fish passage through dams using a combination of modifying operations, such as deep drawdowns, and structural changes, along with other measures to balance water management flexibility and meet recovery obligations for fish listed under the Endangered Species Act, the Corps says in its DEIS.
“Native Fish Society and our conservation partners are excited to finally see what the Corps is proposing when it comes to operating the 13 dams on the Willamette system for the next several decades,” said Jennifer Fairbrother, Conservation Director with the Native Fish Society. “This is an important step in a process that was initiated five years ago by our litigation against the Corps for their failure to implement the existing Biological Opinion and associated plan to recover these fish. We will continue to advocate for those actions we believe are necessary to ensure that native fish species like salmon and steelhead not only survive but have a real chance to once again become healthy, self-sustaining populations.”
This draft is the first EIS for the dams since 1980, 42 years ago. Since that time, upper Willamette spring Chinook and winter steelhead were listed as threatened in 1999 under the federal ESA; bull trout were listed as threatened in 1999; and Oregon chub were listed in 1993. All are present in the Willamette River system. The chub was delisted in 2015, the first time a fish has been delisted in the U.S.
“Over the ensuing four decades following completion of the 1980 EIS (1980 – 2022), operations have been modified and structural measures for fish passage and temperature control have been implemented to improve conditions for ESA-listed fish species,” the Corps said when releasing the DEIS for comment, Friday, Nov. 25.
The DEIS describes and evaluates impacts related to a No Action Alternative and seven other action alternatives.
The more than 2,200 page draft EIS is here.
The preferred alternative would result in less generation at the dams due to spring and fall deep drawdowns designed to aid juvenile downstream fish passage through Cougar Dam’s diversion tunnels. The dam is located on the McKenzie River. The Corps estimates the entire system generation would drop by 18 average megawatts, or enough to power 14,334 households annually. Although the 13 dams’ total maximum generating capacity is 495 MW, the average varies. In August 2019 in an average water year, according to the Corps, generation averaged 184.4 MW.
The impetus behind the DEIS is a March 2018 lawsuit in federal district court in Eugene, OR, by conservation organizations. Plaintiffs Northwest Environmental Defense Center, WildEarth Guardians and Native Fish Society, represented by attorneys at Advocates for the West, asked the court to force the two federal agencies – the Corps and NOAA Fisheries – to reevaluate the impacts of the Corps’ Willamette Valley dams on the threatened fish, to reinitiate consultation and to make immediate operational adjustments to dams on four tributaries of the Willamette River (North Santiam, South Santiam, McKenzie and Middle Fork Willamette) that the groups say block between 40 and 90 percent of spawning habitat.
The last biological opinion by NOAA Fisheries of the Willamette River dams’ operations was in 2008. However, when the lawsuit was filed 10 years after the BiOp had been released, many of the actions required by the BiOp’s reasonable and prudent alternative had not been implemented by the Corps. The RPA is composed of a suite of alternatives that, if implemented, would be expected to not jeopardize the continued existence of the threatened fish.
A final order in the lawsuit was issued Sept. 1, 2021 by U.S. District Court Judge Marco Hernandez. In his final order, he included interim actions the Corps must take to protect threatened wild spring chinook and winter steelhead, while it completes an EIS and until NOAA completes a new BiOp.
He assigned an expert panel to develop implementation plans for each sub-basin in the Willamette River basin. In the final order, Hernandez found that these measures were necessary because, “[a]s evinced by the listed species’ continuing decline, the Corps’ failure to provide adequate fish passage and mitigate water quality issues is causing substantial, irreparable harm to the salmonids.”
He wrote in his final decision that the Corps’ lack of actions is “pushing the UWR Chinook and steelhead even closer to the brink of extinction. The record demonstrates that the listed salmonids are in a more precarious condition today than they were at the time NMFS issued the 2008 BiOp.”
In a presentation to the Northwest Power and Conservation Council’s Fish and Wildlife Committee in February this year, the Corps’ Ida Royer, Columbia River Fish Mitigation program manager, said that a couple of structural items listed in the 2008 BiOp’s RPA had been completed, such as a new adult salmon collection facility at Minto Hatchery on the North Fork Santiam River, and a temperature control tower at Cougar Dam (actually it was completed in 2007 under a previous BiOp) to aid downstream juvenile salmon migration on the McKenzie. Other RPAs, such as water temperature and flow control at Detroit Dam, on the North Santiam, are operational measures, she said.
However, most of the RPAs the Corps completed prior to the 2018 lawsuit were for planning and design. In addition, the Corps until recently had not implemented spill or deep drawdowns at dams for juvenile migrants, also requirements of the 2008 BiOp.
Each of the alternatives evaluated by the Corps in its DEIS consist of a unique suite of measures that are characterized into general categories: flow, water quality, downstream fish passage, upstream fish passage, and measures common to all action alternatives such as gravel augmentation and operation and maintenance of adult fish facilities, among others, the Corps says.
ESA-focused objectives for the alternatives are:
1. Allow greater flexibility in water management (related to refill, drawdown timing, and other water management measures).
2. Increase opportunities for the creation of nature-based structures during maintenance of USACE-owned revetments (structures that help prevent bank erosion).
3. Allow greater flexibility in hydropower production.
4. Increase ESA-listed fish passage survival at WVS dams.
5. Improve water management during the conservation season to benefit anadromous ESA-listed fish and other authorized project purposes.
6. Reduce pollutant levels to restore impaired water quality associated with the WVS dams to benefit anadromous ESA-listed species.
7. Reduce spawning and rearing habitat competition caused by hatchery fish.
The No Action Alternative is required by NEPA to provide the existing condition or baseline as of spring 2019 for comparison of environmental effects of the alternatives. This alternative does not meet the purpose and need of the project because the current operating conditions of the Willamette system adversely affect ESA-listed fish species, specifically UWR Chinook salmon, UWR steelhead, and bull trout, and the designated critical habitat for these species, the DEIS says.
Alternative 1 includes structural measures for temperature control, fish passage and total dissolved gas abatement. It is the second most expensive alternative. With this alternative flows would be reduced to congressionally-authorized minimum flow requirements which would allow for the greatest increase in total storage. Additionally, many of the structural measures allow for fish passage and temperature management that do not result in lower reservoir elevations in the spring through fall.
Although Alternative 1 did rank highest for downstream survival and three out of four UWR spring Chinook salmon populations would reach replacement, only two out of four UWR spring Chinook salmon populations would have high persistence (e.g., a low risk of extinction). Additionally, the McKenzie Core Legacy UWR spring Chinook salmon population would remain at risk of extinction.
Alternatives 2A, a Hybrid Alternative with the Cougar floating screen structure, was developed to improve fish passage through the WVS dams using a combination of modified operations and structural improvements, along with other measures to balance water management flexibility and meet ESA-listed fish obligations, the DEIS says.
The uncertainty that a floating screen structure would effectively collect juvenile fish migrating downstream at Cougar Dam – coupled with uncertain mitigation options to improve such a structure compounded with the high cost to design, construct and operate the facility, led the Corps to not select Alternative 2A as the Preferred Alternative, the DEIS says.
Alternative 2B, a Hybrid Alternative with a Cougar Diversion Tunnel Modification, was developed to improve fish passage through the WVS dams using a combination of modified operations and structural improvements, along with other measures to balance water management flexibility and meet ESA-listed fish obligations. Alternative 2A uses a structure that operates with existing reservoir fluctuations to pass fish downstream, whereas Alternative 2B includes an operation where the reservoir is drawn down to use the diversion tunnel to pass fish.
Alternatives 3A, also referred to as the Operations-Focused Fish Passage Alternative, would primarily use Willamette Valley System dam operations for water quality and fish passage. Alternative 3A ranks fifth for downstream survival and the McKenzie Core Legacy population is at risk of extinction. However, there would be habitat gains for bull trout compared to the No Action Alternative.
Alternative 3B, also referred to as the Operations-Focused Fish Passage Alternative using Diversion Tunnel at Cougar, would primarily use WVS dam operations for water quality and fish passage
Alternative 4 takes a structures-based approach to improve fish passage through the WVS dams to increase the survival of ESA-listed fish. Alternative 4 proposes only structures for water quality and downstream fish passage, shifting the release of stored water from the spring into the summer and fall and augmenting instream flows by using the power and inactive pools. In contrast to Alternative 1, Alternative 4 proposes the “Integrated Temperature and Habitat Flow Regime” operation, the targets of which are generally higher and more variable than those in the congressionally authorized minimum flow requirements proposed under Alternative 1. Alternative 4 also proposes the most structural measures for fish passage and water quality of any alternative. Alternative 4 includes a fish passage structure and water temperature control tower at Hills Creek Dam and a fish passage structure at Cougar Dam but replaces the water temperature control tower at Green Peter Dam proposed in Alternative 1 with using operational measures to utilize the spillway and ROs for temperature management. Alternative 4 proposes an upstream passage structure at Hills Creek Dam and not at Green Peter Dam.
Alternative 5 is the Corps’ Preferred Alternative. In contrast to Alternative 2A, Alternatives 5 and 2B result in only three of the four UWR Chinook salmon populations with high persistence. This is the biggest difference in how Alternatives 5 and 2B perform for the ESA objectives compared to Alternative 2A, a result of the downstream fish passage measure proposed at Cougar Dam. Alternative 2A proposes a floating screen structure and Alternatives 5 and 2B propose a deep drawdown to pass fish through the diversion tunnel. The difference in the number of populations with high persistence is because the ESA models assume increases in downstream survival with a structure at Cougar Dam than through a deep drawdown operation. However, there is higher confidence that the diversion tunnel operation at Cougar will be successful making the likelihood of meeting the ESA objective more certain to occur.
The Willamette River is 180 miles long and drains 11,487 square miles or nearly 12 percent of the state of Oregon. It meets the Columbia River at Portland. Today, over 70 percent of Oregonians live in the Willamette River basin.
The Corps’ Willamette Valley Project, which is a part of the Federal Columbia River Power System, includes 13 federal multipurpose dams across four sub-basins. The dams were constructed between 1941 and 1969 to reduce flood risks in the Willamette Valley and provide hydropower generation, recreation, water quality, municipal drinking water and irrigated agriculture benefits, a February 8 Council memorandum says. Most of the dams are “high head” dams, over 250 feet tall and as a result, the Project overall blocks about 70 percent of chinook and 33 percent of steelhead historic habitat in the upper Willamette basin while also modifying downstream habitat. In key sub-basins, 90 percent of spring chinook and nearly 40 percent of winter steelhead historic spawning habitat is blocked.
Public Comments
• Tuesday, December 6, 5:30 p.m. – 6:30 p.m.
• Thursday, December 8, 12:00 p.m. – 1:00 p.m.
The Corps says it will consider all comments received during the comment period and will respond to comments in the Final EIS. If applicable, the Final EIS will reflect changes to the DEIS based on public comments and/or information made available since publication of the DEIS. All public comments will be included in the USACE EIS record.
Public comments must be submitted in writing or via email correspondence by email or postal service mail.
For email, send comments by Jan. 15, to willamette.eis@usace.army.mil. Please add “Willamette Valley System Draft EIS” in the subject line of the email.
For comments through USPS, send comments to:
U.S. Army Corps of Engineers
Attn: CENWP-PME-E / Willamette EIS
P.O. Box 2946
Portland, OR 97208-2946
Please add “Willamette Valley System Draft EIS” in the subject line of submitted letters.
For background, see:
— CBB, February 24, 2022, CORPS DETAILS TO COUNCIL NUMEROUS MEASURES TAKEN AT WILLAMETTE PROJECTS TO AVOID JEOPARDIZING LISTED SALMON, STEELHEAD, HTTPS://CBBULLETIN.COM/CORPS-DETAILS-TO-COUNCIL-NUMEROUS-MEASURES-TAKEN-AT-WILLAMETTE-PROJECTS-TO-AVOID-JEOPARDIZING-LISTED-SALMON-STEELHEAD/
— CBB, September 2, 2021, JUDGE ISSUES FINAL ORDER FOR OPERATIONS AT CORPS’ WILLAMETTE VALLEY DAMS TO AID ESA SALMON, STEELHEAD; DEEP DRAWDOWNS, SPILL, HTTPS://CBBULLETIN.COM/JUDGE-ISSUE-FINAL-ORDER-FOR-OPERATIONS-AT-CORPS-WILLAMETTE-VALLEY-DAMS-TO-AID-ESA-SALMON-STEELHEAD-DEEP-DRAWDOWNS-SPILL/
— See CBB, July 15, 2021, “Federal Judge Orders Corps To Take Immediate Action To Protect ESA-Listed Willamette Valley Wild Spring Chinook, Steelhead; ‘No Patience For Further Delay,’” https://columbiabasinbulletin.org/federal-judge-orders-corps-to-take-immediate-action-to-protect-esa-listed-willamette-valley-wild-spring-chinook-steelhead-no-patience-for-further-delay/
— CBB, August 26, 2021, “Willamette River Reservoirs Far Below Average As Parties Move Forward On Court-Ordered Interim Measures To Address Listed Steelhead, Chinook,” https://columbiabasinbulletin.org/willamette-river-reservoirs-far-below-average-as-parties-move-forward-on-court-ordered-interim-measures-to-address-listed-steelhead-chinook/
— CBB, November 12, 2020, “Corps Modifies Operations At Willamette Valley Dam To Improve Juvenile Salmon Passage As Court Case Continues On ‘Remedies’ For Wild Salmon/Steelhead,” https://columbiabasinbulletin.org/corps-modifies-operations-at-willamette-valley-dam-to-improve-juvenile-salmon-passage-as-court-case-continues-on-remedies-for-wild-salmon-steelhead/
— CBB, August 19, 2020, “Federal Judge Rules Corps Not Moving Fast Enough To Halt Continued Decline of ESA-Listed Upper Willamette River Wild Spring Chinook/Steelhead; ‘Significant Measures Never Carried Out,’” https://columbiabasinbulletin.org/federal-judge-rules-corps-not-moving-fast-enough-to-halt-continued-decline-of-esa-listed-upper-willamette-river-wild-spring-chinook-steelhead-significant-measures-never-carried-out/
— CBB, November 21, 2019, “NOAA Says Corps’ Draft Proposal On Managing Willamette Dams/Reservoirs Likely To Jeopardize Salmon, Steelhead,” https://columbiabasinbulletin.org/noaa-says-corps-draft-proposal-on-managing-willamette-dams-reservoirs-likely-to-jeopardize-salmon-steelhead/
— CBB, May 30, 2019, “Details On Proposed Detroit Dam Water Temperature Control Tower, Fish Passage Facility To Boost ESA-Listed Steelhead, Spring Chinook,” https://columbiabasinbulletin.org/details-on-proposed-detroit-dam-water-temperature-control-tower-fish-passage-facility-to-boost-esa-listed-steelhead-spring-chinook/
— CBB, April 6, 2019, “Court Hears Arguments For Immediate Changes At Willamette Dams To Aid ESA-Listed Salmonids,” https://columbiabasinbulletin.org/court-hears-arguments-for-immediate-changes-at-willamette-dams-to-aid-esa-listed-salmonids/
— CBB, March 15, 2019, “Corps Proposal For Downstream Fish Passage At McKenzie River’s Cougar Dam Out For Review,” https://columbiabasinbulletin.org/corps-proposal-for-downstream-fish-passage-at-mckenzie-rivers-cougar-dam-out-for-review/
— CBB, February 8, 2019, JUDGE SAYS NO TO EXPEDITED HEARING BUT LAWSUIT OVER WILLAMETTE BASIN DAMS MOVES FORWARD, HTTPS://CBBULLETIN.COM/JUDGE-SAYS-NO-TO-EXPEDITED-HEARING-BUT-LAWSUIT-OVER-WILLAMETTE-BASIN-DAMS-MOVES-FORWARD/
— CBB, March 16, 2018, “Conservation Groups Sue Federal Agencies Over ESA-Listed Willamette Salmon, Steelhead,” https://www.www.www.columbiabasinbulletin.org/440366.aspx
— CBB, November 3, 2017, “Conservation Groups Announce Intent To Sue Corps Over Willamette Chinook, Steelhead,” https://www.www.www.columbiabasinbulletin.org/439813.aspx
- Columbia Basin Snowmelt, Runoff In Most Areas Early, Rapid; Water Supply Forecasts May-September Dropping - 05.15.2025
- Spring Runoff Older Than You Think: Hydrologists Show Mountain Streamflow Old Snowmelt On Years-Long Underground Journey - 05.15.2025
- Columbia River Harvest Managers Confirm Spring Chinook Return On Track, Approve 14 More Fishing Days - 05.15.2025
Leave a Reply
Want to join the discussion?Feel free to contribute!