The US Bureau of Reclamation is well on its way to failing to adhere to its 2026 Sacramento River Temperature Management Plan (TMP). The cold-water pool supply in Shasta Reservoir has fallen as low on this date in 2026 as it was in critical drought years 2015 and 2022 (Figure 1). Survival of winter-run Chinook salmon in the Sacramento River from brood years 2015 and 2022 was less than 5 percent because the cold-water-pool supply in Shasta Lake was exhausted before the end of summer. Reclamation is again creating similar conditions that threaten this year’s production onf winter-run and fall-run Chinook salmon in the upper Sacramento River below Shasta Reservoir.

The 2026 TMP proposed relaxing the requirements for salmon under the National Marine Fisheries Service’s (NMFS) 2024 LTO Biological Opinion for the Long-Term Operation (LTO) of the Central Valley Project and the State Water Project. Reclamation implemented TMPs under the LTO Biological Opinion in 2024 and 2025. 2024 and 2025 were similar water years that, like 2026, had above-average April storage in Shasta Reservoir. Part of Reclamation’s stated rationale is that 2026 had a low snowpack and thus a smaller cold-water pool in Shasta Reservoir.

Reclamation moved ahead with the 2026 TMP despite not receiving the approval of the State Water Board. The conflict with the Board is mainly over the target end-of-September (EOS) storage in Shasta Reservoir, with Reclamation planning for a 2.2 million acre-feet (MAF). The “Shasta Framework” in the LTO Biological Opinion calls for EOS Shasta storage of 2.4 MAF.

Also at issue is Reclamation’s ability to fulfill the TMP’s commitment to maintain a water temperature of 53.5°F at the Clear Creek gage near Redding through October 31 to protect salmon reproduction. Reclamation has achieved that temperature through July. A cooler than normal spring helped sustain the cold-water-pool supply. However, Reclamation is rapidly using up the cold-water pool by meeting high contractor water demands, by using cold water from Shasta to offset the import of warm Trinity-Whiskeytown water (about 15-20% of total Keswick Dam releases to the upper Sacramento River), and by maximizing peaking-power production at Shasta Dam.

Keswick Dam releases in July are a steady 13,000 cfs, providing approximately 6,000 cfs of contractor demands and 7,000 cfs flows and 68°F target water temperatures in the lower Sacramento River (at Wilkins Slough gage above the mouth of Feather River). At that rate, EOS Shasta storage of even 2.2 MAF will be difficult to achieve without exceeding agreed-to water temperature conditions. Reclamation will prematurely exhaust Shasta’s cold-water pool (Figure 1). Target water temperatures in the lower Sacramento River will be exceeded, as in past years.

Comparison of 2026 with Water Years 2024 and 2025, and Drought Year 2022

At the beginning of spring 2026, there was less snowmelt and a smaller cold-water-pool volume in Shasta Reservoir than there had been in 2024 and 2025 (Figure 2). The spring cold-water-pool conservation period was warmer, but the cold-water release target nevertheless started promptly on May 15. It will continue through October 31, unless the cold-water pool is depleted in September or October, as occurred in 2024.

Reclamation’s 2026 TMP is comparable to water year 2020 TMP, a dry water year (Figure 3). In 2020, the EOS storage was close to the 2.2 MAF target, but Reclamation failed to preserve the cold-water pool. Beginning in September and lasting through November, Reclamation released water from Keswick Dam that exceeded the temperature target in the 2020 TMP. The failure to sustain the cold-water supply increased mortality during the spawning and early incubation season of the winter-run salmon (September-October) and fall-run salmon (October-November).

Summary

In 2026, Reclamation must at minimum immediately revise its TMP to include the following criteria:

• Reclamation must revise its present plan for contractor water deliveries. Otherwise, Reclamation will not meet temperature requirements to protect the salmon through the end of the irrigation season and beyond. Reclamation will have to reduce water deliveries to the 2020 levels or less to save the cold-water-pool supply and meet temperature criteria (Figure 4). The cold-water-pool supply in late July is at the drought year 2015 and 2022 level (see Figure 1), yet the Shasta Dam cold-water release is triple the 2022 level and double the 2015 level (Figure 5).
• Reclamation must maintain water temperatures at a maximum of 53.5°F and 56°F at the Clear Creek and Balls Ferry gages, respectively, through October.
• Reclamation must maintain maximum water temperatures of 68oF at the Wilkins Slough gage in the lower Sacramento River.
• Reclamation must meet a target Shasta Reservoir EOS storage of 2.4 MAF.

Figure 1.

Figure 2. Shasta Reservoir storage and release temperature 2024-2026 with annotations.

Figure 3. Shasta Reservoir storage and release temperature 2020-2022 with annotations.

Figure 4. Keswick Dam releases (cfs) May-Oct 2020 and 2024-2026.

Figure 5. Daily average flow release (cfs) from Keswick Dam May-Oct 2015, 2022, and 2026.

Water year 2026 is an average or normal year in terms of total precipitation, similar to 2024 and 2025 (Figure 1).

On April 29, 2026, the Bureau of Reclamation sent a Draft Sacramento River Temperature Management Plan (TMP) to the State Water Resources Control Board (State Board) for review. The Draft TMP stated that it would manage Shasta Reservoir (near Redding) in 2026 according to a drier-year standard than the amount of actual storage in Shasta Reservoir required on paper. The requirement is given in the National Marine Fisheries Service’s 2024 Biological Opinion for the Long-Term Operation of the Central Valley Project and State Water Project (LTO).

Reclamation explained that it based its classification of 2026 on the “Action 5” Operations Plan for the LTO. Action 5 is Reclamation’s modification of the 2024 LTO Biological Opinion. Reclamation adopted Action 5 in December 2025 to comply with a January 2025 presidential order to increase water deliveries.

The Draft TMP also proposed locations on the Sacramento River where Reclamation would meet water temperatures to support spawning and egg incubation of winter-run Chinook salmon. June is the peak spawning season for winter-run salmon below Shasta Dam.

The State Board responded to Reclamation on May 15, 2026 with a comment letter on the Draft TMP.  The State Board’s comments requested additional analyses, including reduced deliveries and increased end-of-September storage in Shasta Reservoir.  On June 1, 2026, Reclamation issued a Final TMP whose proposed operations were functionally the same as those that Reclamation proposed in the Draft TMP.

On June 10, 2026, the Executive Director of the State Board sent a response to the Final TMP to Reclamation “objecting to the final TMP as per the language in Water Rights Order 90-5.” However, the Executive Director’s response does not specify any specific actions the State Board will take against Reclamation. Instead, it requires Reclamation to meet 53.5ºF in the Sacramento River at Clear Creek (River Mile or RM 290) through the summer and to report to the State Board when water temperatures do not meet 56ºF at Balls Ferry (RM 276). 53.5ºF in the Sacramento River at its confluence with Clear Creek provides about ten miles of river with water cold enough for salmon eggs.

In June 2026, Reclamation released water from Shasta Reservoir to maintain Sacramento River temperatures at 56ºF at Bend Bridge (RM 258). Also in June, Reclamation released enough water to deliver approximately 6000 cubic feet per second (cfs) of water to its contractors along the Sacramento River (Figure 2).

The State Board’s main problem with Reclamation’s TMP is the high amount of Shasta releases (approximately 12,000 cfs, or 24,000 acre-feet per day) to meet both the temperature standards and contractor demands. Those releases are expected to increase in July. In combination, this level of release could deplete Shasta’s cold-water pool before the end of the salmon spawning and incubation season.

The Board is concerned because prior-year TMPs failed to maintain Shasta’s cold-water pool through the salmon spawning seasons (Figure 3 and 4). Spawning success of fall-run salmon and winter-run salmon was compromised in past years with relatively average precipitation.

The challenge is to make sure there’s enough water for all uses through autumn. The State Board wants a plan that targets 2.4 million acre-feet of storage in Shasta Reservoir at the end of September, as shown in Figure 5. This is the amount shown on paper in the Biological Opinion that governs Shasta Reservoir. It is unclear how, even with Reclamation’s “Action 5” modification of the Biological Opinion, Reclamation arrived at its proposed lower end-of-September storage level.

Achievement of end-of-September Shasta storage of 2.4 million acre-feet could mean cutting back on scheduled water deliveries or finding a balance with river flows and water temperature goals.

Other possibilities to reduce summer and autumn water temperatures in the Sacramento River include adjusting the timing and volume of water Reclamation imports from the Trinity River to the Sacramento River through Whiskeytown Reservoir. They also include modifying Reclamation’s hydropower operations at Shasta Dam; Reclamation’s turbines sometimes draw water from relatively warm parts of Shasta Reservoir.

Figure 1. Eight-River Index in June 2026 compared to past years. Source: CDEC.

Figure 2. From May 1 through mid-June 2026, Reclamation did not meet water temperature standards in the upper Sacramento River at the Bend Bridge (BND) or in the lower Sacramento River below Wilkins Slough (WLK). In mid-May and mid-June, Reclamation was delivering about 6000 cfs to contractors from the Sacramento River upstream of Wilkins Slough.

Figure 3. Sacramento River water temperature at Clear Creek gage near Redding June through October 2024 and 2025. Dotted red line is water temperature target of temperature management plans in 2024 and 2025.

Figure 4. Sacramento River water temperature and streamflow at Bend Bridge gage near Red Bluff June through October 2024 and 2025. Dotted blue line is water quality standard and permit requirement for water temperature. Note general lack of compliance in June, August, and September of both years. Note also drops in flow from14,000 to 8,000 cfs over the summer can lead to winter run salmon redd dewatering and winter-run egg and alevin mortality.

Figure 5. Shasta Reservoir water storage and releases in drought year 2022 and average year 2026. The State Board wants a Temperature Management Plan from Reclamation that meets a target end-of-September storage of 2.4 million acre-feet.