A Possible Chance to Save Some Sacramento River Salmon in 2021

The Problem

The 2021 target upper water temperature limit for salmon spawning and gravel-bed egg incubation below Shasta/Keswick dams on the Sacramento River near Redding was 55oF.  It is a little late for that now.  Since September 1, Keswick releases have been greater than 56.5ºF, and are now approaching 58ºF.  That’s too warm for the winter-run salmon who have finished spawning (Figures 1 and 2).

But what about the far larger run of fall-run salmon during their peak October spawning?  Can water temperatures downstream of Keswick be lowered back to 55oF in October?  The answer is a qualified yes.

Figure 1. Daily average water temperature of Sacramento River near Redding (SAC gage), September 1-21, 2021.

Figure 2. Daily average water temperatures from Shasta Dam powerhouse (TCD), immediately below Shasta Dam (SHD), and from Keswick Dam (KWK) to Sacramento River, September 1-21, 2021.

The Solution

A “qualified yes” means it would be a complex undertaking involving two actions possible under Reclamation’s operation of its Shasta/Trinity Division:

  1. Switching most or all of Shasta releases to the cold-water lower river outlets of the dam and ceasing warm-water hydropower releases from the dam’s powerhouse.
  2. Minimizing warm-water hydropower releases from Whiskeytown Lake to Keswick Reservoir.

Much of the remaining cold-water pool in Shasta Reservoir is being used to overcome warm-water hydropower releases into Keswick Reservoir (~60oF or higher) before water is released to the Sacramento River below Keswick Dam.  Cutting hydropower releases and rationing the available cold-water-pool supply through Shasta Dam’s lower river outlets is therefore a potential solution to warm water releases to the river.  Though this would reduce hydropower in the short-term, it would save storage in the long-term.

The solution would require a substantial reduction in Shasta Reservoir releases to ensure the cold-water-pool is not exhausted over the next month or more.  However, reducing releases would lower river water levels and strand salmon redds or reduce egg-embryo survival of remaining active winter-run redds or any newly spawned spring-run and fall-run redds.

A possible resolution is to drop flows after the vast majority of winter-run fry have left their redds and before most of the fall-run salmon have spawned.  This has been the standard management approach in many years to save storage – sometime in late September or in October.

Further Context

Under present conditions in late September 2021, access to the cold-water pool in Shasta Reservoir occurs primarily during the afternoon/evening, during peaking-power releases (Figures 3-5) from the penstocks via the Temperature Control Device (TCD) on the face of the dam.  Side-gate openings on the TCD (Figure 6) are able to pull cold water from below only during peak releases.  This pattern indicates that a modified solution might be to reduce warm-water power releases during non-peak operations, while retaining some peaking power releases from Shasta Dam in combination with lower level dam outlet releases.

Figure 3. Hourly flow releases from Shasta Dam September 18-23, 2021.

Figure 4. Hourly water temperature of water releases from Shasta Dam September18-23, 2021.

Figure 5. Hourly water temperature of water releases from a Shasta Dam penstock September18-23, 2021.

Figure 6. Shasta Dam conditions and operation on September 15, 2021.


Addendum to the State Drought Plan – August 31, 2021, Part 3: Reclamation’s Bad Plan Left Fish Agencies with September Hobson’s Choice

Earlier this summer, the Bureau of Reclamation’s operations of Shasta Reservoir, under its Drought Plan jointly developed with the California Department of Water Resources (DWR), caused high water temperatures that delayed spawning of winter-run Chinook salmon to early summer (mid-June through mid-July).1 Winter-run salmon leave the redds after 2-3 months, which in 2021 will mean a mid-August through September peak emergence.

In their Addendum to the State Water Project and Central Valley Project Drought Contingency Plan issued August 31, 2021, Reclamation and DWR state how an increase in September releases responded to a request from fisheries agencies:

In the July Drought Plan update, Reclamation’s forecast for releases to the Sacramento River were 7,850 cfs in August, ramping down to a monthly average of 5,200 cfs in September, and then going back up to 7,550 cfs in October to move the transfer water referenced above. In late August, the fishery agencies reviewed updated data indicating that a flow of approximately 6,800 cfs was needed through early-October to protect several remaining winter-run Chinook salmon redds. As a result, Reclamation modified its previous plan and held releases at 6,800 starting August 26.

Not so fast. In 2021, as in 2014, Reclamation cast the die early in the year, releasing too much water that was too warm until late June (Figures 1 and 2). That was Reclamation’s call, not the choice of the fish agencies. The agencies know that in drought year 2014, Reclamation also maintained both high flow releases and high water temperatures early in the summer, and that therefore the winter-run salmon spawned late. The agencies also know that a drop the water level 2-3 feet at the beginning of September 2014 (Figures 1 and 2) proved catastrophic to eggs and alevin still in the redds. Such drops in water level, with most redds in 1-3 ft of water, cause dewatering, reduced inter-redd water flow, sedimentation within the redd, lower dissolved oxygen, higher redd water temperatures, early hatching, direct egg/embryo mortality, and restricted fry movement within and emergence from redds.

The planned drop in early September of 2-3 feet in water level, part of the original 2021 Drought Plan, was a bad part of bad plan from the get-go. In 2015, Reclamation at least tried to avoid the drop by keeping releases lower throughout the summer (Figures 1 and 2). The August Addendum insinuates that added loss of storage in September-October to maintain higher flow/stage was the result of fishery agency review, when the agencies never wanted nor originally approved the September drop in river flow. The steady flow/stages in 2015 (Figures 1 and 2) was the appropriate prescription.

Just as it was a happy circumstance for the Sacramento River Settlement Contractors that Reclamation delivered them too much water north of the Delta early in the year, it was a happy circumstance for Reclamation and the Settlement Contractors that their planned water transfers of about 200 thousand acre-feet (TAF) to buyers south of the Delta just happened to be ready to go just as the drop planned earlier in the summer was scheduled to happen. Transfer water in a market where prices are north of $1000/AF is the mother’s milk of the change in September Shasta operations (Figure 3).

The accelerated schedule of transfers from Shasta storage also reduces the opportunity for the State Water Board or its Executive Director to wake up and smell the receding predictions for the reservoir’s receding shoreline. The tables at the end of the August Addendum now predict end-of-November storage in Shasta to be an unprecedented 729 TAF, down from the July Addendum’s prediction of 849 TAF. The only numbers that have maintained relative consistency throughout the summer 2021 Sacramento River debacle are the levels of deliveries and transfers. That consistency has been matched and enabled by the silence of the Water Board.

In summary, the original 2021 Drought Plan did not address the real risk of redd stranding that proved devastating for the winter-run salmon spawn in summer 2014. The July-August 2021 stage drop was bad enough and should have been avoided, given that high water temperatures delayed the spawn of winter-run to late June. The fish agencies were cornered into choosing between a large September 1 stage drop in a bad original plan and the buy-now-but-pay-later option of maintaining higher flows through September. The additional drain on Shasta storage and Reclamation’s increasing inability to maintain cold water releases through October show the folly and poor design of the original Drought Plan.

This post is part 3 in a series on DWR and Reclamation’s August Addendum to the 2021 Drought Plan.

Figure 1. River stage below Keswick Dam June-October 2014, 2015, and 2021.

Figure 2. River stage at Bend Bridge, 60 miles below Keswick Dam June-October 2014, 2015, and 2021.

Figure 3: Reclamation’s Delta Exports August 15-September 15, 2021.

Addendum to the State Drought Plan – August 31, 2021, Part 2: This Is a Test(?)

The California Department of Water Resources (DWR) and the U.S. Bureau of Reclamation (Reclamation) released a Central Valley Drought Contingency Plan Update on August 31, 2021. Part of the Addendum’s section on Sacramento River Temperature Management describes bypassing Shasta Dam’s hydropower generating facilities in order to cool Shasta Reservoir releases to the lower Sacramento River:

Reclamation performed a cold water power bypass test on August 29 to determine the feasibility of using the bypass to cool Sacramento River temperatures in the late summer and early fall. The results of this test and any potential future partial bypass will be discussed with the fishery agencies through the Sacramento River Temperature Task Group to determine the potential benefits and impacts of taking the action and ultimately whether the group recommends a partial power bypass for consideration.

The Test

As summarized in the quote above, Reclamation conducted a test on August 29. The test involved releasing cold water from near the bottom of the dam rather than from the power penstock through the Temperature Control Device (TCD) tower on the inside face of the dam. Water temperatures of releases from the TCD steadily increased through late August as the water level in the reservoir continued to fall (Figure 1). Side gate intakes on the TCD were taking in increasing amounts of warmer water from near the surface each day (Figure 2).


The August 29 morning test involved releasing cold water from the bottom of Shasta Reservoir (with minimum TCD release). As expected, it dramatically reduced water temperatures (about 4º F), at the head of Keswick Reservoir immediately downstream of Shasta Dam, while the test was going on (Figure 3). The test was followed by the normal afternoon peaking-power, warmer releases from the TCD, penstocks, and turbines/powerhouse (Figure 4). It was difficult to determine the proportion of releases from the two sources (the blend) in the morning, but it was obvious that water released during the morning of August 29 was cooler than water released at other times during that day or other days that week. The effect of the August 29 test on the Sacramento River below Keswick Dam was barely noticeable (Figure 5).


Releasing cold water from Shasta Dam’s bottom outlet reduces river water temperature below Shasta Dam compared to release through the TCD. However, the Addendum leaves options for a “potential future partial bypass” of Shasta Dam’s power facilities a complete black box.

The prospective objective of a partial power bypass would be to cool the Sacramento River downstream of Keswick Dam, where the salmon are. So many more factors affect release temperatures from Keswick. The release from Shasta of 1000 acre-feet of water over a six-hour period, in a day when the total Shasta release was close to 14,000 acre-feet, offers little insight into a two or three-month strategy for managing the already-diminished cold-water pool that remains in Shasta Reservoir following a spring and summer of excessive releases by Reclamation.

Setting aside the element of time for a moment, Keswick release temperatures depend on the ratio of the colder water released from Shasta Dam to the warmer power releases from both Shasta Dam and Whiskeytown Dam (through the Spring Creek Powerhouse) to Keswick Reservoir. An immediate measure Reclamation can take to reduce the temperature of the Keswick release is to cease the 1000+ cfs it is releasing to Keswick from Whiskeytown.1 In the short term, this could bring the Keswick release close or closer to the 55º target maximum for the 10-mile reach downstream of Keswick.

Increasing the proportion of releases from Shasta’s bottom outlet would reduce water temperatures in the short-term. However, how long this benefit would last, and whether there would be a net improvement or the opposite over one month or two months, involves calculus of how much cold water the change in operations would drain from the cold-water pool, and how quickly. In this regard, the description in the August Addendum says nothing at all about “the action” or potential actions that “will be discussed” by the Sacramento River Temperature Task Group.

Reclamation has put itself in a position where deciding which fish to save is inseparably deciding which fish to sacrifice. Those may be the same fish: the fish saved now by decreasing water temperatures to protect eggs in the redds may die later when Reclamation runs out of accessible cold water to keep the alevin from those eggs alive in a month. About this, the breezy report of a test says nothing at all.

Then there is the unknown but potentially even more severe consequence of depleting Shasta storage this year in the face of looming disaster if water year 2022 is dry.

This post is part 2 in a series on DWR and Reclamation’s August Addendum to the 2021 Drought Plan.

Figure 1. Water temperature of Shasta powerhouse releases in August 2021.

Figure 2. Shasta Reservoir water temperature profile and TCD intake operation configuration at end of August 2021.

Figure 3. Water temperature of Shasta Dam releases 8/27-9/4 2021. Note August 29 morning power bypass test.

Figure 4. Flow from Shasta Dam August 27 – September 4, 2021.

Figure 5. Comparison of daily average water temperatures of Shasta and Keswick Dam releases in August 2021. Most of the difference is caused by warm water releases from Whiskeytown Reservoir (Trinity water) via Spring Creek power to Keswick Reservoir. Note the apparent small effect of August 29 power-bypass test on both river and TCD water temperature: water temperature leveled off rather continuing upward trend over previous 12 days.

  1. Spring Creek Powerhouse temperature had steadily increased to 57º by July 15, when the CDEC gage stopped reporting data.  The August Addendum says that Reclamation plans to reduce by half the Spring Creek Powerhouses releases it predicted in it July Drought update; Reclamation should finish the job and shut it down completely until the water is sufficiently cool.

Addendum to the State Drought Plan — August 31, 2021, Part 1: the Art of the Euphemism

The California Department of Water Resources (DWR) and the U.S. Bureau of Reclamation (Reclamation) released a Central Valley Drought Contingency Plan Update on August 31, 2021, stating:: “Project operations are still tracking with the operations forecast included in the July Drought Plan addendum. August has been fairly typical, with operations primarily controlled by system-wide depletions and Delta salinity.”  This is like a dispatch from the captain of the Titanic saying: the ship was tracking course since the last report, and yes, it hit the iceberg.  As is fairly typical under such circumstances, it sunk, primarily due to the hole in the hull.

The “depletions” that caused the current gaping hole in Shasta Reservoir’s storage and the resulting lethal downstream water temperatures, to reach full effect in September, didn’t just happen.  These glibly described “depletions” are primarily the excessive deliveries to Sacramento River Settlement Contractors to which this blog, CSPA, and others have been vociferously objecting since March.  And, of course, what is sunk is not the good ship Reclamation.  It is the year’s cohorts of Sacramento River salmon, just like in the disasters of 2014 and 2015.

Shasta-Keswick Storage Releases to the Upper Sacramento River

In 2021, Reclamation has not heeded the lessons learned in the 2013-2015 drought.  In 2021, Reclamation has not even implemented the feeble salmon-saving drought actions it applied in 2014 and 2015.

  1. April-May Keswick storage releases were higher in 2021 than 2014 (+257 TAF) and 2015 (+185 TAF) (Figure 1). Reclamation restricted releases in 2014 and 2015 in April-May to preserve Shasta’s cold-water pool.  It did no such thing in 2021.
  2. The higher releases in 2021 led to depleted storage in Shasta Reservoir (Figure 2). Storage at the end of May 2021 was 200 TAF lower than in May 2014, after having been 200 TAF higher at the beginning of April.
  3. The measures to maintain steady flow/stage and water temperature prescribed for drought year 2015 were not applied in 2021. In 2021 operations reverted to the 2014 regime, or worse.

Spawning Conditions for Winter Run Salmon

Winter-run salmon spawn from April to August, with a June-July peak in the ten miles of river downstream of Keswick Dam.  Early season (April-May) flow and water temperature conditions were erratic in 2014, 2015, and 2021 (Figures 1-4).  Rising flows and water temperatures stimulate the spawning migration and maturation leading up to the spawn.  Water temperature above 65ºF hinder migrations and stress adult spawners.  Water temperatures above 60ºF delay spawning and stress eggs in female salmon and eggs/embryos in redds.

  1. Conditions in 2014 proved devastating for the salmon spawn because of high water temperatures in late summer as Reclamation lost access to Shasta’s cold-water pool due to low storage. In addition,  a late summer drop of 2-3 feet in the stage height of the Sacramento River downstream of Keswick Dam caused spawning interruption and redd stranding (Figure 3).
  2. Despite concerted efforts in 2015 to retain storage, to maintain steady flows (and stage), and to sustain colder water releases, water temperature proved too high (>55ºF) for good egg/embryo survival. The lesson learned led to the current target for good survival of <53ºF in Keswick releases.
  3. Operations in 2021 were devastating, starting with high spring water temperatures, followed by a short period of good conditions in late June designed to stimulate spawning, before higher water temperature (Figure 4) and falling stage height greeted later winter-run spawners and egg/embryos/fry in redds.

Migration Conditions for Adult Salmon in Lower Sacramento River

Water temperatures in the lower Sacramento River 100-200 miles downstream of Shasta Dam remained far from typical in 2021 (Figure 5).  For the most part, water temperature from May through August were above the minimum stress level of 68ºF, and above the 72ºF avoidance level for weeks at a time.  These conditions not only affected the late migration of winter-run salmon, but also that of the spring-run (in spring) and fall-run (in summer) who spawn in early fall.


In summary, Reclamation’s operations of Shasta Reservoir have been as bad in 2021 as they were in 2014 and 2015, or worse.

Future posts will discuss more aspects of the failures of Reclamation’s Shasta operations in 2021.

Figure 1. Water releases from Keswick Dam (river mile 300) to the lower Sacramento River near Redding CA, April-August 2014, 2015, and 2021.

Figure 2. Shasta Reservoir storage (acre-feet) April-August in 2014, 2015, and 2021.

Figure 3. River Stage in Sacramento River below Keswick Dam April-August in 2014, 2015, and 2021.

Figure 4. Water temperature in Sacramento River below Keswick Dam April-August 2014, 2015, and 2021.

Figure 5. Water temperature in the lower Sacramento River at Wilkins Slough (river mile 120) May-August 2021, along with average for past 13 years. Note that the State’s year-round water quality standard for the lower Sacramento River is for water temperature to remain below 68ºF.

A Tale of Two Below-Normal Water Years – 2016 and 2020 More Shasta Reservoir Solutions to Save Salmon

Water years 2016 and 2020 were below-normal water years in the Central Valley. Water year 2016 followed three critically dry, drought years, whereas 2020 followed two wet years (2017 and 2019) and one normal (2018) year. So one might assume that 2020 would have been better for Sacramento River salmon than 2016. But it ain’t so – because two different federal administrations were managing Shasta operations. The Trump administration’s policy to “maximize deliveries” of water that began in 2020 had consequences that turned deadly for salmon in critically dry 2021.

First and foremost, Shasta Reservoir storage in 2016 was surprisingly about 500,000 acre-feet or more higher than it was in 2020 after the first of April (Figure 1). Although water year 2020 started out nearly 2 million acre-feet (MAF) higher after a wet year, Shasta storage rose sharply in 2016, nearly filling (4.6 MAF capacity) with winter rain. But the real question is why reservoir storage did not recover in spring 2020. The reason is simply that in 2020, high spring and early summer reservoir releases for water deliveries released water from Shasta almost as fast as it was coming in (Figure 2). If in mid-March, when the reservoir storage was at 3.5 MAF in both years, similar storage-release constraints were in place in 2020 as in 2016, then 2020 would have ended the summer about 500,000 acre-feet higher than it did, near the 2016 storage level (Figure 3).

As a consequence of the storage difference and summer reservoir management, water temperatures downstream of Shasta Reservoir were significantly higher in 2020 than they were in 2016 (Figures 4 and 5). One reason for this was a much reduced volume of the Shasta Reservoir cold-water pool in 2020 compared to 2016 (Figure 6).

In conclusion, the Bureau of Reclamation managed water for winter-run salmon in normal water year 2016 much better than it did in normal water year 2020. Knowing the reservoir would likely not fill in 2020, Reclamation should have deployed a more conservative spring and summer release pattern, similar to what it did in 2016, to sustain cold-water releases from the reservoir through the summer and fall.

Figure 1. Shasta Reservoir water storage (AF) in 2016 and 2020.

Figure 2. Keswick Reservoir to the lower Sacramento River from April-October in 2016 and 2020.

Figure 3. Shasta Reservoir storage in 2016 and 2020 along with author-calculated adjusted release for 2020 if flow release pattern in 2016 (Figure 2) had been employed.

Figure 4. Water temperature below Shasta Dam April-October 2016 and 2020.

 Figure 5. Water temperature below Keswick Dam April-October 2016 and 2020. Note target safe water temperature for salmon spawning and egg incubation is 53ºF.

Figure 5. Water temperature below Keswick Dam April-October 2016 and 2020. Note target safe water temperature for salmon spawning and egg incubation is 53ºF.

Figure 6. Coldwater pool volume (TAF) in Shasta Reservoir in 2016 and 2020, and other years.