Attachment 1 Court Injunction Measures Pertinent to Contract Requirements W9217N25R0005.pdf

W9127N25R0005 Attachment 1 – Court Injunction Measures Pertinent to Contract Requirements

North Santiam River Sub-basin: Detroit and Big Cliff Dams

Description of Operations for Downstream Fish Passage and Water Temperature Management (Abbreviated from Implementation Plans & Long Term RM&E Plan):

The Corps will modify Detroit Dam operations during the fall drawdown and winter months once the reservoir elevation is less than 100 feet over the turbine intakes (elevation 1450 -1500 feet). The turbines will only be operated at Detroit Dam during the day (unless otherwise dictated by downstream water temperature conditions), while a non-turbine outlet will be prioritized to pass flow at night (from dusk until dawn), with no turbine operation (no power generation) during this period except for Station Service if needed for emergencies or for downstream TDG management.

To reduce downstream water temperatures during the fall while Chinook salmon are spawning and their eggs incubating, the Corps will provide downstream water temperature management throughout late spring, summer, and fall at Detroit Dam through strategic use of the spillway, turbines and upper and lower ROs. Spillway operations will start when the reservoir reaches spillway crest elevation (El. 1541.0 ft) and continue until the reservoir is drafted below the spillway crest. From there, a combination of turbine and upper and lower RO discharges will be implemented until water temperature management is no longer possible due to reservoir turnover. With adaptive management, the spill ratio will be adjusted so water temperatures (as measured at the USGS gage downstream of Big Cliff) can best meet targets.

The Corps will operate multiple spillway gates at Big Cliff Dam to spread total flow across the spillway and reduce TDG levels below Big Cliff Dam. The operation occurs when the Corps is operating the Big Cliff spillway (e.g., high flow events over the 3200 cfs turbine capacity). The Corps will monitor TDG downstream and identify the extent that TDG criteria is met under this operation.

Management Purpose and Biological Goal: <Excerpt from Long Term RME Plan> The overall goal is to establish self-sustaining populations of spring-run

Chinook salmon and, while not currently present above Detroit Dam, winter steelhead upstream of Detroit Dam. The objective of this measure is to provide volitional passage for juvenile Chinook salmon at Detroit and Big Cliff dams in spring with high passage efficiency, and high immediate and long-term survival.

In addition, the management of water releases from Detroit and Big Cliff dams is intended to maintain downstream temperatures within specified temperature criteria, while maintaining acceptable level of TDG.

The target fish for the fall passage operations would be subyearling Chinook salmon that entered the reservoir in the previous winter–spring and reared through summer in the reservoir, and subyearling Chinook salmon that enter the reservoir in summer and fall.

The primary target fish for the spring operations would be Chinook salmon fry and subyearlings that enter the reservoir in late winter and spring, and yearlings that either enter the reservoir in late winter and spring (small number) or entered the reservoir in the previous winter-fall and remained through the winter.

The intent is to determine if changes in dam operation improve downstream fish passage conditions at Detroit and Big Cliff dams compared to previous operations as a result of implementing this operation. The metrics of interest include juvenile spring Chinook salmon migration timing into the reservoir, migration timing through the reservoir, passage timing, passage size and condition, passage rate and survival.

South Santiam River Sub-basin: Green Peter Dam and Foster Dam

South Santiam River Sub-basin: Green Peter Dam

Description of Operations for Downstream Fish Passage and Water Temperature Management (Abbreviated from Implementation Plans & Long Term RM&E Plan):

Initiate a drawdown of Green Peter Reservoir in the fall, so as to achieve the targeted elevation of 780 ft. by winter. Inter-seasonable adjustments will be necessary and modeling results should be considered a general guideline.

Discharge during drawdown will likely range between 3,000 and 4,000 cfs, except as may be required by flood risk management (FRM) operations or during Chinook spawning. From September through mid-October, Green Peter and Foster Dam outflows will be managed to maintain flows between 1,500 and 3,000 cfs in the South Santiam River downstream from Foster Dam to protect Chinook spawning, to the extent possible.

The targeted elevation of 780 ft. is approximately 35 feet over the regulating outlets (ROs) at Green Peter Dam. As soon as the reservoir is drawn down below minimum power pool (El. El. 887 ft.), the Green Peter powerhouse will cease operation and all water will be discharged through the ROs. The reservoir will be held at or near El. 780 ft. for approximately one month unless FRM dictates otherwise.

In the spring, the Corps will release water from the spillway once the Green Peter Reservoir reaches El. 971 ft. Spill will be carried out continuously until May 1 or for at least 30 days, whichever is longer. At least two different spill strategies will be tested in a block study: (1) continuous (24/7) spill through a minimum gate opening of 1.5 ft. and (2) nighttime spill through a 3–4 ft gate opening one hour before sunset to one hour after sunrise. Additional spill may continue throughout the summer for water temperature management. This will be adaptively managed and may change from year to year, depending on climate and hydrologic conditions. Operations in spring 2023 are summarized in the respective Green Peter Dam implementation plan and may be modified by mutual agreement of the Corps and National Marine Fisheries Service (NMFS) as warranted.

Management Purpose and Biological Goal: <Excerpt from Implementation Plans and Long Term RM&E Plan> The overall goal [of the Green Peter Dam drawdown] is to establish a self-sustaining population of spring Chinook salmon upstream of Green Peter Dam.

The goal of this drawdown operation measure is to provide volitional downstream passage and survival for juvenile spring Chinook salmon and steelhead through Green Peter Reservoir and past Green Peter Dam in the fall with high passage efficiency and high immediate and long-term survival. The target fish for the fall operations would be salmon fry and subyearlings that entered the reservoir in the previous winter–spring and reared through summer in the reservoir, and subyearlings that enter the reservoir in summer and fall. The number and proportion of salmon fry that remain and rear in the reservoir will depend on the passage effectiveness of spring operations under Measure 12a. The number and proportion of stream-reared summer and fall migrants after adult Chinook salmon are outplanted will be determined through RM&E activities under this measure (traps upstream of reservoir) and Measure 12a (traps upstream of reservoir and life history sampling in streams upstream of the reservoir.

South Santiam River Sub-basin: Foster Dam

Management (Abbreviated from Implementation Plans & Long Term RM&E Plan):

Starting after Labor Day weekend, Foster Reservoir will be drawn down to a forebay elevation of 620–625 ft. by October 01. From October 1–December 15 the Foster spillway will be operated from one hour before sunset to one-half hour after sunrise; turbine unit 1 (only) will be operated at station service to reduce/balance TDG levels created by the spill operation. Spill gates should be opened to a 1 ft. gate opening; outflow amounts will be dictated by reservoir elevation. Flows will be spread across multiple gates if necessary. During the day, the Foster turbine units will be operated from one-half hour after sunrise to one hour before sunset, with full generation. The spillway will not be used to discharge water during this time unless required for flood risk management.

Starting 01 February maintain Foster Reservoir at minimum conservation pool (El. 613 ft.) prioritizing spillway operation from one hour before sunset to one-half hour after sunrise. During the day (one-half hour after sunrise to one hour before sunset, the Foster turbine units will be operated with full generation. The spillway will not be used to discharge water during this time unless required for flood risk management. On 15 May the Corps will begin refilling Foster Reservoir using stored water from Green Peter Reservoir and South Santiam River inflow targeting full pool of Foster Reservoir by Memorial Day Weekend.

From May 16 – June 15, operations at Foster Dam will continue as described above.

From June 16 – late July, the focus of Foster operations will transition to downstream water temperature control. The fish weir will be installed in one spillbay and operated continuously (day and night) to improve downstream water temperatures and upstream migration. Outflows from the fish weir are approximately 300 cfs.

Management Purpose and Biological Goal: <Excerpt from Implementation Plans and Long Term RM&E Plan> The overall goal [of the Foster operations] is to establish self-sustaining populations of spring Chinook salmon and winter steelhead upstream of Foster Dam. The goal of this spill operation is to provide improved downstream fish passage and survival for juvenile spring Chinook salmon and steelhead through Foster Reservoir and past Foster Dam [including operating Foster Dam in a manner that reduces reservoir holding time and increases downstream passage survival for juvenile salmonids]. A primary objective of the delayed refill operation is to provide conditions for volitional passage of juvenile Chinook (especially fry, including fry that pass Green Peter Dam) as well as winter steelhead.

The target fish for the fall operations would be salmon fry and subyearlings that entered the reservoir in the previous winter–spring and reared through summer in the reservoir, and subyearlings that enter the reservoir in summer and fall.

Juvenile winter steelhead (age 0 and age 1) are present in the reservoir and have been observed in high numbers in the forebay. Although few steelhead were caught downstream of the dam in previous years, fall spill operations could provide passage opportunities for these fish. Passage would also be provided for juvenile salmon migrating past Green Peter Dam.

The target fish for the spring operations would be salmon fry and subyearlings that enter the reservoir in winter–spring and juvenile salmon that reared through fall-winter in the reservoir. Juvenile winter steelhead pass the dam in the spring as age 2 smolts. Age 1 juvenile steelhead are also present in the reservoir and may benefit from passage measures. Passage would also be provided for juvenile salmon migrating past Green Peter Dam.

South Fork McKenzie River Sub-basin: Cougar Dam

Management (Abbreviated from Implementation Plans & Long Term RM&E Plan):

The Cougar Reservoir will be drawn down to elevation 1505 ft. from early

November through December 15. Once Cougar Reservoir is drawdown to El.

1571 ft. and below, the regulating outlets (ROs) will be operated at night, and powerhouse (i.e., generate) during the day. From El. 1532 ft. to El. 1505 ft., the ROs will be prioritized at all times to discharge water from the reservoir. On December 16, the Cougar Reservoir refill will begin and use the ROs during nighttime hours until El. 1532 ft. is reached. The diversion tunnel will not be used during this special operation.

After the winter drawdown of Cougar Reservoir, initiate reservoir refill to the minimum conservation pool El. 1532 on December 16. Hold the reservoir to El.

1532 ft. until 01-March. On 01 March, begin to draft Cougar Reservoir to El.

1520 ft., targeting this elevation on 01-April. The intent is to provide an increased downstream flow signal that encourages outmigration of fish from the reservoir.

Delay refill from 1520 ft. as long as possible, while maintaining a high likelihood of reaching El. 1571 ft. by July 1. For the entirety of the spring operation, the ROs should be prioritized at night when passage is highest. Generation is allowed during the day. Note: additional powerhouse discharges may be required depending on rain events, inflow conditions, or downstream water quality values.

Use adaptive management to determine the refill starting date. The decision on when to initiate refill will be made by the Federal agencies’ Flow and Water Quality Management Team (FWQMT) considering hydrologic data from April and May, including snowpack, average weekly inflows, and extended Water Supply forecasts from the NW River Forecast Center, and fish migration data from trapping upstream and downstream of the reservoir and dam.

After the winter drawdown of Cougar Reservoir (IM 14), initiate reservoir refill to the minimum conservation pool El. 1532 on December 16. Hold the reservoir to El. 1532 ft. until 01-March. On 01-March, begin to draft Cougar Reservoir to El. 1520 ft., targeting this elevation on 01-April. The intent is to provide an increased downstream flow signal that encourages outmigration of fish from the reservoir. Delay refill from 1520 ft. as long as possible, while maintaining a high likelihood of reaching El. 1571 ft. by July 1. Use adaptive management to determine the refill starting date. The decision on when to initiate refill will be made by the Federal agencies’ Flow and Water Quality Management Team (FWQMT) considering hydrologic data from April and May, including snowpack, average weekly inflows, and extended Water Supply forecasts from the NW River Forecast Center, and fish migration data from trapping upstream and downstream of the reservoir and dam.

Management Purpose and Biological Goals: <Excerpt from Implementation Plans and

The metrics of interest include spring Chinook juvenile passage timing, passage size and condition, passage rate and survival.

The objective of the fall measure is to provide volitional passage for juvenile

Chinook salmon at Cougar Dam during fall and early winter with high passage efficiency, and high immediate and long-term survival.

The target fish for the fall operations would be salmon fry and subyearlings that entered the reservoir in the previous winter–spring and reared through summer in the reservoir, and subyearlings that enter the reservoir in summer and fall. The number and proportion of salmon fry that remain and rear in the reservoir will depend on the passage effectiveness of spring operations under Measure 15.

Determine if downstream fish passage conditions at Cougar Dam have improved compared to previous operations as a result of implementing this operation.

RM&E should be prioritized to understand active outmigration versus reservoir use (i.e., “movers” and “stayers”).

The target fish for the spring operations would be salmon fry and subyearlings that enter the reservoir in late winter and spring, and yearlings that either enter the reservoir in late winter and spring (small number) or entered the reservoir in the previous winter-fall and remained through the winter. The number and proportion of juvenile salmon in the latter group will depend on the passage effectiveness of fall-winter operations under Measure 14.

Determine if downstream fish passage conditions at Cougar Dam have improved compared to previous operations as a result of implementing this operation. Results will used to determine whether structural improvements/modification to Cougar’s regulating outlets will be necessary to ensure safer fish passage. RM&E should be prioritized to understand active outmigration versus reservoir use.

Middle Fork Willamette River: Dexter Dam, Lookout Point Dam, Hills Creek Dam

Middle Fork Willamette River Sub-basin: Fall Creek Dam

Description of Operations for Downstream Fish Passage and Water Temperature Management (Abbreviated from Implementation Plans & Long Term RM&E Plan):

Extend the drawdown of Fall Creek reservoir from December 1 through January

15. Ensure that Fall Creek Reservoir hits streambed (El. 780-785 ft.) by December 01. Hold at this elevation through January 15. On January 16, begin refill to El. 700 ft. and hold at this elevation (+/- 3 ft.) for the spring passage operation (Injunction Number 20), except as needed to provide downstream flood damage reduction or sediment management. The Corps may need to provide flushing flows to clear the RO tailrace of sediment.

Fall Creek Reservoir will refill from streambed level to El. 700 ft starting January 16 and will be held at that level until March 15, except as needed for flood control or sediment management. Refill, following rule curve, will begin on March 16.

The overall goal is to establish a self-sustaining population of spring Chinook salmon upstream of Fall Creek Dam. The goal of this drawdown operation is to provide downstream fish passage and high survival for juvenile spring Chinook salmon through Fall Creek Reservoir and past Fall Creek Dam.

The target fish for the fall operations would be salmon fry and subyearlings that migrated downstream in the previous winter–spring and reared through summer in the reservoir, and subyearlings that enter the reservoir in summer and fall (before drawdown). The number and proportion of salmon fry that remain and rear in the reservoir will depend on the passage effectiveness of spring operations under Measure 20.

The target fish for the spring operations would be salmon fry and subyearlings that migrate downstream in late winter and spring, and yearlings that migrate downstream from winter through spring.

[The purpose of the fall/winter measure is to] extend the opportunity for juvenile Chinook salmon to pass through the reservoir and past the dam in the late fall and early winter. The metrics of interest for biological monitoring include juvenile Chinook salmon passage timing, passage rates, and passage survival.

The primary objective of [the spring] measure is to provide safe and timely passage for young- of-year juvenile Chinook salmon that enter Fall Creek reservoir such that they may avoid extended reservoir residence and express their natural life-history strategy. The metrics of interest include juvenile Chinook salmon passage timing with an emphasis on fry.

Middle Fork Willamette River Sub-basin: Lookout Point and Dexter Dams

Management (Abbreviated from Implementation Plans & Long Term RM&E Plan):

The Corps anticipates, beginning in 2023, to draw down the Lookout Point

Reservoir to elevation 750 ft. in the winter while prioritizing use of the regulating outlets (ROs) during this time. Drawdown likely to be initiated in late summer / early fall, using a combination of the spillway, regulating outlets and powerhouse.

Once the reservoir is below minimum conservation pool, the ROs will be used exclusively to pass outflows.

Starting as early in March as possible, and once Lookout Point Reservoir elevation reaches 2.5 feet over spillway crest (El. 890 ft.), continuous, ungated spillway releases will be implemented at Lookout Point Dam, along with continuous gated spill at Dexter Dam. Spill operations will be implemented continuously (24/7) for at least 30 days at both projects. After the 30-day continual ungated spill operation, transition to a nighttime, gated spill operation with generation during the day at Lookout Point and Dexter for as long as water is available and downstream conditions allow.

When water temperatures as measured at the USGS gage downstream of Dexter Dam near 60°F, operate the Lookout Point ROs to reduce downstream water temperatures.

The overall goal is to establish a self-sustaining population of spring Chinook salmon upstream of Lookout Point Dam. The goal of the [spring measure] is to provide volitional passage for juvenile salmon at Lookout Point Dam in spring with high passage efficiency, and high immediate and long-term survival. Safe, timely, and effective passage includes minimizing juvenile residence time in Lookout Point reservoir. Objectives of the spring spill are twofold: first to reduce residence time in Lookout Point Reservoir. This will subsequently reduce the risks of predation and copepod infestation by increasing migration rates through the reservoir. Second, to increase passage survival at the dams. At a larger scale, an objective of the spring spill is to increase survival of juvenile salmon below Dexter Dam.

The target fish for the spring operations would be salmon fry, subyearlings, and stream-reared yearlings that enter the reservoir in late winter and spring; and subyearlings that entered the reservoir in the previous winter–fall and remained through the winter.

Intent of spring operations is to provide operations that minimize reservoir rearing time and reduce turbine passage for juvenile Chinook salmon at Lookout Point and Dexter dams. Determine if downstream fish passage conditions through Lookout Point Reservoir and at Lookout Point and Dexter dams have improved compared to previous operations as a result of implementing this operation. Compare passage of juvenile Chinook salmon under 30-day continuous spill to that under nighttime spill. RM&E should be prioritized to understand active outmigration versus reservoir use.

General research questions are:

What is the travel time of juvenile salmon from reservoir entry to the forebay during conditions of spring spill and how does it compare between continuous spill and nighttime spill, and to previous years with limited or no spill?

What is the passage rate and passage survival of juvenile salmon during spring spill and how does it compare between continuous spill and nighttime spill, and to years with limited or no spill?

The metrics of interest include migration timing into the reservoir, migration timing through the reservoir, size at passage, dam passage rates and passage survival.

Middle Fork Willamette River Sub-basin: Hills Creek Dam

Management (Abbreviated from Implementation Plans & Long Term RM&E Plan):

Once Hills Creek Reservoir is drawn down below El. 1460 ft., operate the regulating outlets daily from 6:00 PM to 10:00 PM. This operation is expected to be implemented from approximately December 1 through March 1.

The overall goal is to establish a self-sustaining population of spring Chinook salmon upstream of Hills Creek Dam. The goal of this drawdown operation is to provide downstream fish passage and high survival for juvenile spring Chinook salmon through Hills Creek reservoir and dam.

The intent is to operate Hills Creek Dam in a manner that reduces reservoir holding time and increases passage survival for juvenile salmonids. The metrics of interest for biological monitoring include juvenile Chinook salmon passage timing, passage rates, and passage survival.

Adult Chinook salmon were not outplanted upstream of Hills Creek Dam in 2021. Therefore, effectiveness of the measure cannot be fully evaluated for this cohort in winter-spring 2022 (for fry) or winter-spring 2023 (for fall migrants, spring yearling migrants, and reservoir residents). However, juvenile salmon from previous outplants would be present and studies could be conducted in winter-spring 2023 with experimental releases.