D2026-01 Top of Page
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| 1. SOR Request |
SPECIFICATIONS: We request the United States Bureau of Reclamation (USBR) to implement a 4-week strategy in 2026 to augment river discharge in the Columbia River from Chief Joseph Dam to Bonneville Dam. The requested strategy consists of: Releasing volumes of water from Grand Coulee Dam each week from 17 April to 15 May. Each weeks flow augmentation from Lake Roosevelt will begin on Friday and end on Thursday. The fish managers will request each weeks augmentation volume no later than the Tuesday before the Friday start of a weeks augmentation (Table 1). The volume should be released as evenly as economically, logistically, and environmentally feasible; said another way, the daily average draft rate should be relatively stable within weeks. The aggregate 4-week drafted volume requested in 2026 will not exceed 1 Maf, but the USBR may release more than 1 Maf from GCL storage if doing so is consistent with guiding documents and authorizations (Appendix 1). A weekly request under this SOR may range from 0 to 500 Kaf and will be informed by river conditions, fish passage timing, and existing constraints of the CRS. Specific Request for 17-23 April 2026: Begin release of 200 Kaf of stored water from GCL on 17 April 2026 to augment flow from Chief Joseph Dam to Bonneville Dam. Complete release on 23 April 2026 with smooth transition to forthcoming Week 2 request that will be provided on 21 April 2026. JUSTIFICATION: The goal of the request is to increase survival of yearling Chinook salmon and steelhead and reduce the amount of time required for smolts to move through the hydrosystem. The 4-week volume-based strategy in this SOR is designed to make spring flow augmentation from Grand Coulee Dam more directly quantifiable and permit effectiveness evaluation as part of the adaptive management process. Background and concepts underlying requested operation: Storage reservoirs and run-of-river dams had profound effects on water velocity through the mainstem Columbia River with consequences for anadromous fishes. Run-of-river projects reduce water velocity year-round by increasing the cross-sectional area of the river channel, while storage reservoirs reduced peak river discharge during spring runoff. The completion of storage reservoirs and implementation of coordinated flood control in the upper Columbia River Basin reduced median spring discharge by 53% at Priest Rapids and 42% at The Dalles (Appendix 2). The consequences of reduced river discharge combined with mainstem run-of-river dam development were quickly apparent (McCann et al. 2024 Chapter 8) and flow augmentation was one of the first strategies implemented to mitigate for hydroelectric development under the Northwest Power Act of 1980. The first Water Budget called for 3.45 Maf of flow augmentation measured at Priest Rapids that fish managers could shape between 15 April and 15 June — this water was shaped out of Grand Coulee Dam. Spring flow augmentation from Grand Coulee continued in modified form following ESA-listing of Snake and Columbia River salmon and steelhead through the 1995 NMFS Biological Opinion and subsequent ESA consultations on the operations of the FCRPS/CRS. The 2020 Proposed Action maintains flow augmentation from Grand Coulee Dam as a mitigation action as weekly flow requests and seasonal average flow targets (USACE, BPA, USBR 2020 Appendix V Section 2.3.2.1). |
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| 2. Requester(s) | Columbia River Inter-Tribal Fish Commission, Oregon Department of Fish and Wildlife, Washington Department of Fish and Wildlife, Confederated Bands and Tribes of the Yakama Nation, Idaho Department of Fish and Game | ||||
| 3. TMT Recommendation |
April 15, 2025, TMT Meeting. This section will be updated soon. |
4. AA decision |
April 15, 2026, TMT Meeting. This section will be updated soon. |
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| 5. Actual Implemented Operation |
April 15, 2026, TMT Meeting. This section will be updated soon. |
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| 6. If different from AA decision, why? | |||||