State and Federal Hatcheries Release Salmon Smolts to Rivers, Delta, Bay, and Coast

Hatcheries in California are releasing tens of millions of salmon smolts in 2022, per normal operations.  State hatcheries are trucking over ten million fall-run salmon to the Bay again this spring because of the drought.  State and federal hatcheries are releasing another ten million-plus fall-run smolts to the rivers near the hatcheries.

Future salmon fisheries will depend mostly on the Bay releases, because few of the hatchery smolts released to the river or wild salmon smolts will survive the journey to the ocean this drought year.  Yet even the prognosis for smolts released to the Bay is poor.  Delta outflows near 4000 cfs under the State’s TUCP will keep survival below one percent (Figure 1).

Meanwhile, the prognosis for wild fall-run smolts under the TUCP is grim as they began moving through the Delta in late April and early May (Figures 2 and 3).  The extra month of normal outflow needed to help the salmon get to the ocean would amount to about 100-150 TAF, less than 10% of what is being supplied to water users from reservoirs in spring 2022.  Is the TUCP allocation to outflow and fish reasonable?

Figure 1. Fall-run salmon adult returns to the American River hatchery from Bay releases vs Delta outflow to Bay at time of release. Years noted are percent returns for below normal years 2016 and 2018, and wet year 2017 under normal rules. Blue dots with outflow below 5000 cfs are from 2014 and 2015, TUCP years. Red line is hypothesized relationship. Returns under normal rules are approximately triple the returns under TUCP rules.

Figure 2. Red circle denotes wild fall-run and spring-run smolts passing through the Delta in late April and early May 2022.

Figure 3. Peak migration of fall-run and spring-run smolts into Bay from Delta in late April and early May 2022.

2022 Sacramento River Operations – Temperature Management Plan

So much is at stake in this water year 2022: water supplies, water quality, agricultural production, hydropower production, as well as the future of salmon, steelhead, sturgeon, smelt, and other native fishes of the Klamath and Sacramento-San Joaquin watersheds. Despite the lessons of the 1976-1977, 1987-1992, 2007-2009, and 2013-2015 droughts, the choices and tradeoffs are more difficult, and effects more significant and consequential to the fish, in 2022, the third year of the 2020-2022 drought. The State Water Resources Control Board is about to approve 2022 water operation plans for Central Valley Project (CVP) and the State Water Project (SWP). Among the most immediate effects of these plans will be the fate of iconic fisheries resources of the Sacramento and Klamath Rivers, in 2022 and beyond.

The two key elements of the plans are (1) the Sacramento River Temperature Management Plan (TMP) governing Shasta/Trinity operations, and (2) the Temporary Urgency Change Petition (TUCP) governing Delta operations. A 4/5/22 post covered some aspects of the TUCP on Delta operations, which serves to cut demands on federal and state reservoir storage in the Sacramento River watershed by lowering Delta outflow requirements. (See also CSPA and allied organizations’ protest and objection to the TUCP.)

This post covers the 2022 TMP, which focuses on Shasta/Trinity storage releases and management of Shasta Reservoir’s storage releases and cold-water pool in support of Sacramento River salmon. It starts with a review of both the hydrological and biological effects of Shasta and Trinity operations in 2021. Starting with 2021 creates context in two ways. First, it explains the severe depletion of CVP and SWP storage in 2021, which created the avoidable portion of the extreme storage conditions of 2022. Second, it describes the disastrous failure to protect fish in 2021, both as consequence of bad management and contributor to the dire conditions of fisheries in 2022.

2021 Sacramento River Operations

The predominant characteristic of 2021’s operations of Shasta Reservoir and the Sacramento River was excessive reservoir storage releases over the spring and summer for water deliveries. Within this constrained context, the dominant biological features in 2021 were management of the cold-water pool for salmon , along with associated “downstream” effects on the lower river and Bay-Delta. The 2021 Sacramento River operations plan led to significantly reduced production in brood year 2021 of all four runs of Sacramento salmon.

I have divided the 2021 story into five event periods (Figure 1), each with differing conditions and outcomes:

Period A: The early-April through early-June period was characterized by rapidly rising high releases (6000-9000 cfs) for water deliveries in late April and May. Reclamation claimed it saved 300 TAF of Shasta’s cold-water pool using power bypass of warm surface water for the high spring releases. In reality, the excessive delivery of irrigation water unnecessarily depleted total Shasta storage by nearly 500 TAF and depleted the cold-water pool by 200 TAF. Those storage losses also crippled any ability to subsequently sustain the cold-water pool through the summer.

The releases of unseasonably warmer water (56-60ºF) also (as planned) inhibited spawning in the late-April to early-June portion of the winter-run salmon spawning season (about half of the historical season). It also stressed winter-run and spring-run adults in their upper river pre-spawn holding areas. Recent scientific studies suggest that such stress (extended holding and warmer water) may have contributed to thiamine deficiencies in spawners that contributed to poor subsequent fry survival and smolt production. Rapidly rising flows and water temperatures may have also compromised late-fall-run salmon egg incubation that normally continues into April. Irrigation deliveries in the middle and upper river led to lower flows and high water temperatures in the lower river (Figures 2 and 3); this both reduced the survival of emigrating spring smolts of all four races of salmon, and hindered and stressed upstream migrating winter-run and spring-run adults.

Period B: The mid-June period of cold-water releases (53-55ºF) was designed to stimulate winter-run adult spawning. It also provided 8000 cfs irrigation releases that unnecessarily depleted total storage and the cold-water pool by 6-8 TAF per day for nearly two weeks (~100 TAF lost cold-water pool and total storage). It also resulted in salmon spawning at 8000 cfs, spawning habitat conditions that led to water surface elevations that increased by one-foot and then dropped by two-feet over the summer salmon egg incubation season. I have not assessed the role of flow on the amount of quality spawning habitat available or on the potential of redd dewatering/stranding, although such factors should also be considered in evaluating an operations plan. Irrigation deliveries in the middle and upper river led to lower flows and high water temperatures in the lower river (see Figures 2 and 3), hindering and stressing winter-run and spring-run adults that were late in migrating upstream.

Period C: The late-June to early-August period was the main winter-run egg incubation period under 2021 operations. Flow releases increased to accommodate irrigation demands. Irrigation diversions, in turn, reduced flows in the river further downstream, leading to high water temperatures (72-78ºF) that blocked early arriving fall-run adult immigrants. A rise of almost two feet in water level in early June from the increased flow likely caused some redd scouring in the upper river spawning reach below Keswick Dam.

Period D: The mid-August to mid-September period was characterized by falling storage releases, associated declining water levels, and warming water as the cold-water pool and access to it declined. Winter-run egg incubation continued through the period and likely suffered from stressful water temperatures and redd dewatering. Flows in the lower river increased, and water temperatures declined, becoming less stressful for upstream migrating adult fall-run.

Period E: The late-September through November period was characterized by continued warming of water temperatures due to lessening access to Shasta’s severely depleted cold-water pool, followed by natural fall cooling. Releases and water levels declined rapidly in the spawning reach. At the beginning of the period, warm water interrupted or delayed spring-run and fall-run spawning, while a water level drop of several feet led to redd dewatering and stranding. Winter-run fry were also subjected to potential stranding during the drop in water level. Spring-run and fall-run spawning was likely hindered or delayed into November due to high water temperatures and decreasing flows and associated water levels.

The 2022 Plan

The May 2 2022 Final TMP Is a radical change from the 2021 plan and actual operations. For the first time, Reclamation has prioritized protection of fish over irrigation deliveries to senior Sacramento River Settlement Contractors. The changes also reflect the much lower available storage in this third year of drought (Figure 4). Water release projections are much lower to sustain the cold-water pool and cool downstream temperatures through the summer (Tables 1 and 2).

April Operations and Effects

April operations closely followed the draft plan that Reclamation submitted to the State Water Board on April 6. April operations using middle TCD gates and small imports of Trinity River water maintained Keswick releases at 52-53ºC and 3250 cfs per the draft 2022 TMP. Such operation helped preserve Shasta storage and the volume of the deeper, cold-water pool (<50ºF). Valley-wide precipitation since mid-April increased flows in the middle and lower Sacramento River, stimulating juvenile salmon emigration and adult spring-run and winter-run salmon immigration. A small pulse flow from Keswick to the 30 miles of spawning and rearing habitat below Keswick Dam would have helped stimulate and benefit these salmon migrations, especially those from the upper 30-mile reach that saw little or no benefits from the April storms, but this did not occur.

The draft TMP (April 6) had the same proposed releases from Keswick Reservoir as the final TMP (May 2). However, the end-of-September storage in Shasta Reservoir predicted in the final TMP (1135 TAF) is over 100 TAF lower than was the prediction in the draft TMP (1250 TAF).

Proposed May Operations

The proposed May 4500 cfs release would come from Shasta Dam’s middle gates with access to warmer surface water in the lake, thus saving some of the cold-water pool. Such savings would require warmer releases that would delay spawning and stress holding adult winter-run and spring-run salmon.

For those winter-run who do spawn in May, egg survival could be compromised by the warmer water. With warming surface waters and warmer reservoir inflows in May, and more pre-spawn adult salmon arriving in the 10-mile spawning reach below Keswick Dam, a Keswick release temperature maintained at or below 51ºF would ensure the 10-mile spawning and holding reach is maintained near 53ºF. A colder release would require proportionately more cold water be released from deeper dam gates.

In reality, middle gate operation through early May (Figures 5 and 6) has sustained cooler-than-expected daily-average release temperatures at 51-52ºF. Hydropower peaking has accessed the warmer upper layers of the reservoir (Figures 7 and 8), saving some of the cold-water pool as planned. However, middle-gate operation under hydropower peaking, and gradual warming of reservoir surface waters, will result in increasing release temperatures per the plan later in May. A rapidly warming reservoir may necessitate use of lower gates or less hydropower peaking operations to maintain <54ºF through May per the plan. If spawning commences in early May due to cooler than planned dam releases, higher late May release temperatures would begin to compromise earlier-spawned egg survival. This should cause some re-evaluation of the plan.

Proposed June-September Operations

The proposed June-September 4500 cfs release (4000 cfs in September) from Shasta Dam will be from the lower TCD gates from the cold-water pool at ~50ºF (Table 2). Slightly higher Keswick Dam release water temperatures are predicted due to warming in Keswick Reservoir at ~4500 cfs through-flow. Water temperatures 5 miles downstream at Highway 44 will increase slightly more due to warm air temperatures.

The final temperature management strategy, based on recommendations received from the Sacramento River Temperature Task Group (SRTTG), is to target 58ºF at Highway 44 during the initial part of the season and then target 54.5ºF for 16 weeks around the estimated peak spawning date of Aug 2. This would result in targeting 54.5ºF from June 7 through September 27 or until the cold water is used up. Due to the limited available control in operating the middle gates (as described above), temperatures in June and July may be cooler than 54.5ºF. Reclamation will operate the TCD to target as close as possible to 54.5ºF to conserve cold water for maintaining target temperatures throughout the critical period.

Reclamation also received feedback from SRTTG members that an initial target of 58ºF would help to conserve cold water for later during the more critical portion of the temperature management season. The problem with this is that it will delay spawning, stressing yet-to-spawn adults and compromising survival of earlier-spawned embryos.

Fall Operations

Fall operations will be similar to those described above for Period E in 2021, with the exception of a lesser drop in flow. Water temperatures in late summer and fall will increase as the cold-water pool is depleted and access to it ends. Increasing temperatures will delay spring-run and fall-run spawning and stress pre-spawn adults (potentially aggravating the thiamine deficiency problem).

Uncertainties

The planners have noted significant uncertainties that will require intensive real-time operations and management throughout the summer to achieve the various goals and targets throughout the system. To address uncertainty, Reclamation has employed conservative estimates of future conditions in the modeling assumptions (e.g., hydrology, operations, and meteorology) and projections, and has included as part of the TMP the potential to make changes, in consultation with the SRTTG, Water Operations Management Team, and/or the Shasta Planning Group. The State Board and NMFS should be included in the decision process.

Infrastructure limitations

The 2022 TMP was developed in consideration of the limitations on using the TCD and the need for temperatures below 56ºF at the Livingston Stone National Fish Hatchery. Efforts to address these limitations should be accelerated. Hydropower peaking operations changes should also be considered.

Related Actions to the Final 2022 TMP

1. Six-Fold Increase in Winter-Run Hatchery Smolt Production
Reclamation plans to fund a six-fold increase in the production of hatchery winter-run smolts this year with staged fall-winter releases from the hatchery and Battle Creek. Such releases should timed to coincide with natural flow pulses and pulse flows from Keswick Dam.

2. Transfers of Adult Salmon
The plan includes the capture and transport of adult winter-run salmon to the headwaters of Battle Creek. Good additional measures would be to give these adult fish thiamine injections and to enhance spawning gravels in Battle Creek as soon as possible.

3. Thiamine Treatments
Stresses imposed prior to spawning (e.g., delayed spawning, low flows, warm water during migration) and holding contributes to thiamine deficiency and high mortality of yolk sac fry, both in hatcheries and wild salmon1. Only hatchery salmon can be treated effectively at adult or egg stage, so efforts should be made to treat any wild adults that are handled, as well as to minimize pre-spawning stresses (e.g., erratic flows and high water temperatures).

4. Water delivery cut to 18% to Settlement Contractors
The TMP proposes to limit water deliveries to Sacramento River Settlement Contractors to 18% of their contracted amounts. The State Board should enforce this limitation. Reclamation should subordinate the timing of water releases to contractors to the needs of salmon downstream of Keswick Dam.

5. Reduced Downstream Deliveries
Demand on Shasta storage for Delta inflow/outflow has been reduced by relying more on other SWP/CVP and non-project reservoirs. However, lower Sacramento River and Delta inflows have reached water temperatures above 65ºF in early May, which puts additional stress on salmon that are immigrating in late spring. It is not a question of whether in May or June lower river water temperatures will exceed 68ºF – the state standard – but when.

6. System-Wide Water Management
Reclamation plans to manage system water supplies to minimize demands on Shasta’s cold-water supply. The Plan and temperature modeling relies on numerous drought actions throughout the Sacramento watershed to reduce reliance on stored water from CVP and SWP reservoirs this summer. “These drought actions have added a degree of flexibility to manage storage at Shasta, Oroville and Folsom reservoirs for meeting public health and safety needs, repelling salinity in the Delta, producing hydropower and providing additional cold water for fishery protection throughout the summer.” In 2022, Reclamation has finally cut deliveries to Sacramento River Settlement Contractors substantially below minimum amounts stated in contracts, in order to protect salmon. However, DWR has not done so for Feather River Settlement Contractors. Reclamation and DWR should be looking at system-wide delivery reductions. Reclamation should also call on New Melones for Delta salinity control as needed. See also NRDC et al. Objection to the TMP (May 6, 2022) for additional recommended system measures.

7. Real-Time Adjustments and Reporting
“Daily releases may vary from these flows to adjust for real-time operations. Significant uncertainties exist within the forecast that will require intensive real-time operations management throughout the summer to achieve the various goals and targets throughout the system.” Reporting, scrutiny, and decision making should be open processes.

8. Restoration of Salmon Upstream of Dams
Reclamation is committed to restoring endangered salmon to their historical habitat upstream of Central Valley rim dams. This program should be accelerated.

Tables 1 and 2 are copied directly from the Final TMP dated May 2, 2022.

Figure 1. Keswick Dam release water release rate and temperature, April-November 2021. Five general periods (A-E) are depicted, based on flow-temperature conditions as described in more detail in text. A. Spring high storage release rate (6-9K cfs), including extensive power bypass releases of warm surface water. B. A late-June cold water release to stimulate winter-run salmon spawning (<53ºF). C. A post-spawn higher irrigation release period with late-egg-stage sustaining water temperatures. D. Cold-water pool saving period with falling flows and higher water temperatures. E. Early fall period with loss of access to cold-water pool and reduction in storage releases.

Figure 2. April-December 2021 Sacramento River flow below Keswick Dam (river mile 300) and below Wilkins Slough (river mile 120). The difference between the two locations, plus tributary and ag return inputs, equals total irrigation deliveries via surface diversions and ground water depletions.

Figure 3. 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. Water temperatures above 65ºF are stressful to migrating juvenile and adult salmon. Water temperatures above 70ºF hinder adult salmon migration. Water temperatures above 75ºF are lethal to salmon.

Figure 4. Shasta Reservoir storage in 2022 and other selected years.

Figure 5. Shasta Reservoir water temperature profile at end of April 2022.

Figure 6. Water temperatures of Shasta and Keswick Dam releases in 2021 and to date in 2022.

Figure 7. Hourly water temperature in Shasta Dam releases, 4/27-5/7 2022.

Figure 8. Hourly Shasta Dam flow releases 4/27-5/7 2022.

  1. Adult salmon thiamine stores reduce most during the pre-spawning fast (Vuorinen et al. 2020).  Vuorinen PJ, Rokka M, Ritvanen T, Käkelä R, Nikonen S, Pakarinen T, Keinänen M. 2020. Changes in thiamine concentrations, fatty acid composition, and some other lipid-related biochemical indices in Baltic Sea Atlantic salmon (Salmo salar) during the spawning run and pre-spawning fasting. Helgol Mar Res. 74(1):1–24. doi:https://doi.org/10.1186/s10152-020-00542-9. (Crossref), (Web of Science ®), (Google Scholar) https://hmr.biomedcentral.com/articles/10.1186/s10152-020-00542-9

Water Projects’ Temporary Urgent Change Petition 3/18/22 Comment on Provision #1 – Spring (April-June) Delta Outflow and Salinity Intrusion

The U.S. Bureau of Reclamation and the California Department of Water Resources (Reclamation and DWR) filed a “Temporary Urgency Change Petition” (TUCP) on March 18, 2020.  If granted, the TUCP reduce Delta outflow requirements.  The proposed averaging requirements in the TUCP pose a problem in addition to the problem of too little overall outflow.

The TUCP states:

Reclamation and DWR are requesting to modify certain terms as the Projects’ storage and inflow may not be sufficient to meet D-1641 requirements and additional operational flexibility of the Projects is needed to support Reclamation and DWR’s priorities, which include: operating the Projects to provide for minimum health and safety supplies (defined as minimum demands of water contractors for domestic supply, fire protection, or sanitation during the year); preserve upstream storage for release later in the summer to control saltwater intrusion into the Sacramento-San Joaquin Delta (Delta); preserve cold water in Shasta Lake and other reservoirs to manage river temperatures for various runs of Chinook salmon and steelhead; maintain protections for State and federally endangered and threatened species and other fish and wildlife resources; and meet other critical water supply needs. (3/18/22 TUCP, p. 1)

The TUCP is requesting reduced Delta outflow requirements for the April 1 through June 30, 2022 period, for the stated primary purpose of preserving storage in Oroville and Folsom reservoirs.   What I term Provision #1 is reduction of outflow requirement from 3-day average of 7,6001 to 14-day average of 4,000 cubic feet per second (cfs).

The requirement in Revised Water Rights Decision 1641 of a 3-day average of 7,600 cfs is meant to keep salt water from encroaching upstream from the Bay into the Delta in drought years like 2021 and 2022.   This helps to protect the beneficial uses in the Delta including fish, fish low-salinity habitat, Delta agriculture, and south Delta water export water quality.  The TUCP’s proposed Delta outflow of 4000 cfs is meant to provide minimum protection in the face of low available water supply (reservoir storage and precipitation).

The overriding problem with the TUCP’s proposed flow reduction is that it does not require enough flow.  Yet, even accepting the need to reduce flow to allow storage of more water in Reclamation and DWR’s reservoirs, the requested change could be modified to better protect beneficial uses.

Under past TUCPs, DWR and Reclamation have used the 14-day averaging window to game operations to skate as closely as possible to the edge of compliance.  This has led to erratic outflows, often below 4000 cfs (Figure 1).  More precise estimates taking into account tides show outflow is lower than intended (Figure 2).  In these circumstances, salinity has increasingly moved up from the Bay into the Delta under such minimum freshwater outflow (Figures 3-6).

I recommend the outflow required be more stable, allowing for only minimal salinity increase over the spring.  A 3-day average of 4,000 cfs measured outflow would provide greater protection of beneficial uses.

Salinity criteria are more easily defined and measured, and more directly related to beneficial uses.  Criteria for Collinsville, Emmaton, Jersey Point, and Old River that have a maximum for a 3-day average or a maximum daily level with a minimum increase over the spring would also be more protective.

Figure 1. Daily Delta outflow estimated from measured Delta hydrology conditions in spring 2014, 2015, and 2021, drought years when previous TUCPs were implemented

Figure 2. Measured Delta outflow into Suisun Bay in spring 2021.

Figure 3. Salinity in eastern Suisun Bay in spring 2021.

igure 4. Salinity in lower end of Sacramento River near Rio Vista in late April 2021.

Figure 5. Salinity and net tidal flow in lower San Joaquin River channel at Jersey Point in spring 2021.

Figure 6. Salinity (EC) and net tidal flow in lower Old River channel in south Delta near Byron in spring 2021.

  1. The normal requirements are stated in Revised Water Rights Decision 1641, Table 3, footnote 10, pp. 185-186.  The April-June requirement in a Critically Dry year is also met if either the daily average or 14-day running average EC (measurement of salinity) at the confluence of the Sacramento and the San Joaquin rivers is less than or equal to 2.64 mmhos/cm (Collinsville station C2).  From May 1 through June 30, if the Sacramento River Index is less than 8.1 million acre-feet, the flows requested in the TUCP would be the same as the required flows under Decision 1641.

Salmon Released from Central Valley Hatcheries

Hundreds of thousands of smolts of endangered salmon are being released to the lower Sacramento River from federal and state hatcheries this winter, the San Francisco Chronicle reported on March 2.1 It is a drought year, and most of the young salmon will likely perish in the jaws of predators on their 300-mile journey to the ocean through the river, Delta, and Bay. Without the protection of adequate river flow, cold water, and turbidity for the journey, there is little hope. Reservoir storage is depleted from the past two years of overzealous water deliveries. What little rain and snowmelt there has been in the Valley is being stored in reservoirs. Warm weather has come early. The 400 thousand smolts released on March 2 could use some help, but they have not received it and are not likely to get it.

River Flow

Flow from Shasta Reservoir to the upper river via Keswick Dam has been minimal (Figure 1, KWK). 40 miles downstream at the Bend (BND) gage near Red Bluff, the river received some snowmelt from tributaries in January, but even that tapered off by the end of January. Flow into the Delta from the Sacramento Valley at Freeport (FPT) reached minimal levels by the end of January. Delta outflow (Figure 2) settled at its minimal prescribed level near 12,000 cfs after some January export taking.

Water Temperature

Warm weather and low flows have allowed water temperatures in the lower Sacramento River and north Delta migration corridor to reach the mid-fifties (Figure 3), temperatures that activate lower river predators like striped bass, resident trout, and pikeminnow.

Turbidity

Turbidities (Figure 4) are now at seasonal lows from the upper river near Red Bluff (RDB) to the Delta near the Rio Vista Bridge (RVB), reflecting clear waters needed by sight-feeding predators like striped bass.

Delta Salmon Salvage

Hatchery salmon smolts released in December at least reached the Delta during the December storms (Figure 5). It remains to be seen if the February and March smolt releases even reach the Delta.

What’s Needed

The article in the Chronicle mentioned that only one of the 140 radio-tagged hatchery smolts released in February has reached the Delta. The March 2 release of 400,000 smolts could use a pulse of cold turbid water from Shasta, Oroville and Folsom reservoirs to help them reach the Bay. So far, only Oroville releases have increased, from 3500 to 5500 cfs in recent days, with the added 2000 cfs showing at Freeport (Figure 1). While this helps near the Delta, it does little for the upper 200 miles of river the smolts have yet to transit.

Figure 1. River flows near Keswick (River Mile-RM 300), Bend (RM 250), and Freeport (RM 50) in winter 2022.

Figure 2. Delta outflow in tidally averaged daily cfs in winter 2022.

Figure 3. Water temperature in Sacramento River near Bend (RM 250), Wilkins Slough (RM 140) and Freeport (RM 50) in winter 2022.

Figure 4. Water turbidity in Sacramento River near Bend (RM 250), Red Bluff (RM 240), Freeport (RM 50), and Rio Vista (RM 30) in winter 2022.

Figure 5. Salmon salvage observed at Delta Fish Facilities in water year 2022.

Yuba River Salmon in 2022

In a December 2020 post, I described the status of the fall-run salmon population in the Yuba River.  Hatchery salmon predominate, while natural production is minimal.  The population remains in a very poor state – at about 10% of recent historical levels during and subsequent to multiyear droughts such as 2007-2009 and 2013-2015 (Figure 1).

In a January 11, 2022 post, the South Yuba River Citizens League (SYRCL) promotes cleaning the two fish ladders at Daguerre Dam half way up the river to the impassable Englebright Dam, in order to provide better passage for spawning salmon to prime spawning habitat.  Without effective ladders, salmon are delayed or even forced to spawn downstream of Daguerre Dam in marginal habitat.  The ladders must be maintained per the federal NMFS biological opinion and take permit to operate Daguerre Dam as a water diversion dam for the Yuba County Water Agency (YCWA).

SYRCL’s plea to clean the fish ladders is helpful in bringing attention to the problems facing salmon (and steelhead) in the lower Yuba River.  However, the fish ladders at Daguerre are only a small part of the problem for Yuba River salmon.  River flows and habitat in the lower Yuba River need improvement.

River Flows

It is instructive to compare flows in 2020 (Figure 2) to flows in 2021 (Figure 3), particularly at the Marysville gage, where water has passed downstream of all the local agricultural diversions at Daguerre Dam.

2020

From May through mid-August of 2020, flows at Marysville averaged about 1000 cfs (Figure 2).  The vast majority of this water was released through YCWA’s New Colgate Powerhouse upstream of Englebright Dam.  In the fiscal year from July 1, 2020 to June 30, 2021, YCWA had revenues from power sales of over $80 million. 1 Water released during the summer creates more power revenue than flows released in spring.

Better management for fish would release more of the water in the spring, providing more areas in the lower Yuba River for juvenile salmon and steelhead to grow and higher flows to move them downstream when they are ready to leave the system.  SYRCL, CSPA, and other conservation organizations, as well as staff from fisheries agencies, have recommended such a change in release pattern during the ongoing relicensing of YCWA’s hydropower project.

Some of this water released in the summer of 2020 was also sold out of the watershed, generally to entities south of the Delta.  In the fiscal year ending June 30, 2021, YCWA also made $12 million on water sales.2 The large flow increase at the end of August 2020 – likely a water sale – had no benefit for fish.  Its biggest effect on fish was that It drew down storage in New Bullards Bar Reservoir, which created a cascading effect in the very dry year 2021, when flows for all purposes were limited by lack of stored water.

2021

In a very dry year like 2021 that follows a dry year like 2020, river flows in spring and summer (Figure 3) become a major limiting factor.  First, there are no late-winter, early-spring flow pulses to attract adult spring-run salmon.  At a flow of 400 cfs at the bottom end of the lower Yuba River, there is insufficient flow to help adult spring-run salmon move upstream through many shallow riffles and through the Daguerre ladders.  Very low late-summer and fall low flows likewise hinder fall-run salmon.  Second, flows in late winter and early spring are too low to efficiently carry juvenile salmon downstream while avoiding the many predators on their way to the Bay and ocean.  Downstream of Daguerre Dam, over-summering juvenile salmon and steelhead must contend with low flows and associated stressful water temperatures.  Additionally, spawning at 400 cfs flow leads to redd scour if fall rainstorms occur: a late-October storm in 2021 brought Yuba flows up to 15,000 cfs and raised water levels nearly 10 feet (Figure 4).

Habitat

Feeding and cover habitat in the lower Yuba River are virtually nonexistent.  Predatory fish abound below Daguerre Dam.  Floodplain off-channel habitat and woody debris are severely lacking, especially during when winter-spring river flows are relatively low.  Many fall-run salmon spawn in poor spawning habitat below Daguerre.  To its credit, YCWA has contributed on a voluntary basis to several habitat improvement projects in the lower Yuba River, including the ongoing restoration at Hallwood.  However, it has vigorously resisted the establishment of regulatory requirements for additional projects.

Biological Opinion (BO)

Keeping the ladders clean is already a mandate.

  • Measures shall be taken by the Corps to minimize the effects of debris maintenance and removal at the Daguerre Point Dam fish ladders.
  • When Yuba River flows exceed 4,200 cfs, the Corps shall provide notifications to NMFS on the status of debris accumulations and fish passage conditions at the Daguerre Point Dam fish ladders.
  • The Corps shall take action within 24 hours, or as soon as it is safe, to remediate fish passage conditions related to debris maintenance and removal at the Daguerre Point Dam fish ladders.
  • The Corps shall, by January 31 of each year, report to NMFS an update on previous year’s debris maintenance and removal actions, including details on amount of debris removed, the timing of removal and the conditions that triggered debris accumulation.
  • The Corps should consider predator removal at Daguerre Point Dam.

 Summary and Conclusions

Flow regimes and habitat improvements are necessary to save Yuba salmon, in addition to ladder repairs and cleaning at Daguerre Dam.  The Yuba River Accord, which has defined lower Yuba River flows since 2008, leaves too much flow in the summer by shorting flows that salmon and steelhead need in the spring.  The channel of the lower Yuba River also needs extensive physical improvement.

Figure 1. Yuba River salmon escapement 1953-2020.

Figure 2: Yuba River flow (cfs) March 1 – September 15, 2020 above (orange) and below (blue)
Daguerre Dam.

Figure 3. Yuba River flow (cfs) March 15 – September 15, 2021 above (orange) and below (blue) Daguerre Dam.

Figure 4. River flow (cfs) and stage (feet) in lower Yuba River below Daguerre Dam near Marysville in fall 2021.

  1. See YCWA financial report for 2021 and 2020 at https://www.yubawater.org/Archive.aspx?ADID=310, pdf p. 14.
  2. Id. Compare wet year 2019, with likely no out of basin water sales, and water sale revenues of $531 thousand.