Category Archives: Chinook Salmon

False River Barrier 2015

Posted on by

This summer’s placement of the False River Barrier in the central Delta has been touted for saving reservoir storage during this fourth year of drought.

Contra Costa Times quoted DWR on the recent removal of the False River Barrier: “The state also managed to reduce the volume of fresh water it released from reservoirs to add to the Delta, preserving the resource instead for the times that salmon need infusions of colder water to survive.” (Contra Costa Times 10/2/15)

DWR also posted: “The barrier helped limit the tidal push of saltwater from San Francisco Bay into the central Delta and minimized the amount of fresh water that had to be released from upstream reservoirs to repel saltwater.”1

A DWR news release stated: “The barrier was an essential part of DWR’s strategy to maintain good water quality in the Delta and preserve water in upstream reservoirs to help keep young salmon cool enough to stay alive downstream of dams….The water users in the interior of the Delta, including many farmers and residents there, would have experienced much higher salinity without it… Monitoring at various stations in the Delta showed that the barrier indeed helped improve water quality in the central and south Delta.”2

Question 1. Did the False River Barrier save reservoir water by reducing release requirements?

A. Shasta – the answer is no, Shasta retained its prescribed releases all summer. There was thus no benefit of False River Barrier in retaining Shasta’s cold-water pool.
B. Trinity – no, it too contributed only to the fixed release to Sacramento River.
C. Oroville – releases to Feather River were relatively high much of the summer contributing substantially to Delta inflow.
D. Folsom – Releases to American River were relatively high all summer contributing substantially to Delta inflow, although depleting the reservoir’s overall storage and cold water pool.
E. New Melones – Stanislaus and San Joaquin flows were minimum all summer.

The overall answer is that slightly less Oroville and Folsom releases may have been needed with the False River Barrier; whether releases were lower or not is difficult to determine

Question 2. Was less freshwater outflow to the Bay required because of the False River Barrier?

No, outflow standards were prescribed by State Board and for the most part were met.

Question 3. Was less freshwater inflow needed to maintain the salinity standards at Threemile Slough, Jersey Point, and South Delta?

Threemile Slough was the controlling compliance point this summer, at times requiring increased Delta inflow and closure of the Delta Cross Channel for compliance. The False River Barrier likely increased the effectives of these measures to lower Threemile salinity.

Question 4. Did False River Barrier result in lower salinity in Central and South Delta?

No, salinities were higher than either 2013 or 2014.

Question 5. Was Franks Tract salinity lower because of the False River Barrier?

No, because salinity entered via the lower San Joaquin from San Andreas Landing via the mouth of Old River, as both these sites had higher salinity than in 2013 or 2014. The lower San Joaquin from Jersey Point to Prisoners Point thus suffered higher salinities in 2015 to meet South Delta export demands without False River inputs.

Question 7. Were South Delta exports higher than would have been possible without the False River Barrier?

Yes, because a higher proportion of freshwater inflow from the Sacramento River via the Delta Cross Channel and Georgiana Slough could be exported with False River closed.

Conclusion:

The Department of Water Resources’ assertion in the news article that salmon benefitted from the False River Barrier is unfounded. There were no measurable savings to reservoir storage or cold water pools essential to salmon.

Salinity found another path into Franks Tract via the mouth of Old River, but to the detriment of upstream movement of the Low Salinity Zone in the lower San Joaquin River. South Delta exports were able to take a higher portion of the freshwater inflow to the Delta from the Sacramento River because of the False River Barrier. Higher South Delta salinities in 2015 demonstrated a willingness to accept higher salinities in exports with the False River Barrier in place or simply an extreme demand for some summer export. Salinities dropped sharply in September with higher freshwater inflows (and outflows) to accommodate South Delta export and water transfers. The transfers were possible as water demands from the Sacramento Valley and Delta sharply declined, and water was sold for transfer south of the Delta. The False River Barrier likely helped facilitate the across-Delta transfers, which declined after the False River Barrier was removed at the end of September.

State Water Projects south Delta exports at Clifton Court Forebay summer 2015

State Water Projects south Delta exports at Clifton Court Forebay summer 2015.

Central Valley Project south Delta exports at Tracy Pumping Plant summer 2015.

Central Valley Project south Delta exports at Tracy Pumping Plant summer 2015.

Hydraulic Injection of Salmon Eggs in River Gravels: A Promising Salmon Restoration Measure

Posted on by

There is an opportunity to alleviate salmon losses during drought years when low river flows and warm water can cause mortality of incubating salmon eggs. The technique was previously used in Alaska that proved to be highly successful in populating under-utilized salmon streams: hydraulic injection of eyed salmon eggs obtained from hatcheries into the natural environment of streams and rivers. It is currently used in some streams in Oregon. Last year, prompted by concerns over anticipated losses of salmon eggs because of warm water, this technique was proposed for the upper Sacramento River and Battle Creek using Coleman Hatchery eggs but was not implemented due to a variety of concerns by the fishery resource agencies. Prominent among those concerns: 1) the technique has never been implemented in California, and 2) it could interfere with the genetic integrity of fall-run salmon in the Central Valley. On this latter concern, as pointed out by Tom Cannon in a prior blog entry, “Studies have shown that [fall-run Chinook] populations across the Valley are homogeneous, with little or no genetic diversity, and consist mainly of hatchery fish and some natural offspring of hatchery fish. There really are no viable “wild” Fall Run Chinook populations left in the Central Valley.”1 Additionally, hatcheries such as Coleman Hatchery purposefully breed natural-origin salmon with hatchery-origin salmon to prevent domestication of hatchery stocks (USFWS 2011).

The egg injection concept is as follows. Using facilities at a Central Valley salmon hatchery (e.g., Coleman Hatchery on Battle Creek or Feather River Hatchery), incubate surplus fall-run Chinook eggs in chilled, sterilized water to eyed stage then hydraulically inject the eggs back into the river after water temperatures have naturally cooled to tolerable levels in November or December. The eggs would be injected using an egg planting device invented by Tod Jones and described by his patent and Vogel (2003) (Figure 1).

Figure 1. The hydraulic egg planting device.

Figure 1. The hydraulic egg planting device.

One objective of this approach would be to partially compensate for the anticipated loss of fall-run salmon production during October caused by deleterious water temperatures in drought years. The intent is to repopulate the river with fertilized salmon eggs originating from a hatchery but hatched and reared in the natural riverine environment. Specifically, the intent would be to reseed the river with fertilized salmon eggs to boost future ocean sport and commercial salmon catch, in-river sport catch, and salmon runs returning to spawning grounds. If properly implemented, the survival of salmon eggs implanted in the river can greatly exceed that of naturally-spawned eggs (Tod Jones, pers. comm., September 8, 2014).

In addition, this approach would help retain the diversity in spawning timing from the salmon lost during the October spawn in warm, drought years. Because salmon primarily return as three-year-old fish to spawn, loss of a major portion of the early-spawning component of the fall-run Chinook could propagate forward in time such that many future generations of salmon may not possess the early spawning characteristics. If actions are not taken to preserve the early spawning component of the fall run, the run three years hence would not only be expected to be depressed but also lack many of the October-spawning fish. Loss of the October spawning component of the fall run will unfavorably truncate the usual timing of spawning to those fish spawning in November and December. Retaining the early spawning component of the fall run will increase resilience of future salmon runs approximately every three years thereafter.

Furthermore, this project could increase the survival of juvenile salmon outmigration. Because fall-run salmon eggs laid during October incubate and hatch earlier than eggs laid later in November and December, the earlier fish are anticipated to emigrate sooner. If the drought persists, an earlier outmigration of salmon would be beneficial because riverine and Delta conditions will be inhospitable for salmon in the spring. For example, the present-day management strategy of Coleman Hatchery is to rear and release the normal smolt production in April when riverine and Delta conditions are more favorable as compared to May when the hatchery previously released salmon during the 1980s.

The egg injection technique has great promise for salmon restoration. It could save many salmon during drought years and could be an invaluable technique to rapidly populate new, presently unused areas envisioned for salmon restoration. It has now been 12 years since this project was proposed for implementation in California: Vogel (2003). It would certainly be preferable to doing nothing and could have potentially saved millions of salmon eggs in the fall of 2014 when conditions in some Central Valley rivers were lethally warm. Hopefully, a pilot demonstration of the egg injection project may be implemented in the fall of 2015 in the Feather River thanks to the cooperation of the California Department of Fish and Wildlife and, depending on the outcome, a larger-scale project in 2016.

References

  • U.S. Fish and Wildlife Service. 2011. Biological assessment of artificial propagation at Coleman National Fish Hatchery and Livingston Stone National Fish Hatchery: program description and incidental take of Chinook salmon and steelhead. July 2011. 372 p.
  • Vogel, D.A. 2003. Evaluation of a proposal for hydraulic salmonid egg deposition. Report prepared for the U.S. Bureau of Reclamation. Natural Resource Scientists, Inc. October 2003. 36 p.

Water Transfer Workshop and Klamath-Trinity-Sacramento Salmon

Posted on by

Water transfers are allowed through the Delta under federal biological opinions during the summer, but in 2015 the period was extended through the fall by the State Water Board, with the approval of the federal fisheries agencies responsible for administering the Endangered Species Act (ESA). There are many types of water transfers, but I am referring specifically here to transfers of federal Shasta-Trinity storage through the Sacramento-San Joaquin Delta to state and federal water contractors south of the Delta. Water released from Trinity and Shasta reservoir storage is passed down the Sacramento River into the Delta where it is exported in the south Delta and then delivered to south-of-Delta water contractors (who purchased the water from northern California contractors who have priority on the Shasta-Trinity water). This was the largest component of water transfers in the Central Valley in 2015.

This week, the Delta Stewardship Council held a workshop on these transfers through the Delta. The Council concluded: “On the issue of single-year water transfers and whether they impacted the coequal goals and therefore should be subject to the Delta Plan’s covered action process, the Council did not feel they had all the information they needed, so a determination was made to exempt single-year transfers from the covered action process until December 31, 2016, and a request made for further information.” 1In other words, the Council decided it needs more information before it can support these single-year water transfers.

At the workshop, DWR’s representative Bill Croyle stated: “2014 was a banner year. People needed the water, there was a little bit more water in the system, it was the third year of a drought, and I think the water transfer system, the market, the experience, the education, and some new tools and also a high level of involvement as necessary from the executive offices of all of our agencies resulted in over 400,000 acre-feet of water being moved to where it was really needed.”

Tom Howard, Executive Director of the State Water Board stated: “Really the concern is in the Delta, and then the question becomes how do you protect Delta resources. The way the water board has been looking at it is if you are meeting all your Delta objectives, then that’s what the water board at least at one time considered adequate to protect public trust resources. We’re in the process of taking another look at that because there have been a lot of issues associated with the existing standards potentially. Also when we did the modeling for a lot of the development of these standards 20 years ago, we didn’t throw a lot of transfers in, so here we are throwing 500,000 – 700,000 acre-feet of transfers or more in a period in a four month period so as we work to update the Bay Delta plan, we will be assuming a large transfer load into the system as well beyond just operation of the projects and how they move water.”

DWR’s Jerry Johns stated: “The Bureau when they did their EIR on long-term water transfers, they also evaluated these impacts and came to the conclusion that there wouldn’t be significant impacts, so I think it has been evaluated in a pretty robust fashion.”

Representing the fish, Bruce Herbold, retired EPA biologist, offered: “So my recommendations on single year transfers is just don’t do them….We’ll have more water in storage upstream, we will have less streamflow modifications, and we’ll have less exports out of the Delta in each year.”2

I agree with Dr. Herbold. The big impact is in the loss of Shasta-Trinity storage, which can be seen in the release of Keswick Reservoir water to the Sacramento River near Redding in the figure below.

Release of Keswick Reservoir water to the Sacramento River near Redding

Sacramento River releases recommended in the 2015 Salmon Plan developed by the State Water Board, fisheries agencies and the Bureau of Reclamation called for 6000 cfs for September and 5500 cfs for October. The 500-1000 cfs extra in September and 1000 cfs extra in October amount to approximately 80 TAF of “extra” storage releases that have gone to transfers so far this year in just six weeks.

The diversion from the Trinity River as seen below as Whiskeytown Reservoir power releases to the Sacramento River (most to Keswick Reservoir via Spring Creek Powerhouse) amounted to approximately 80 TAF between September 1 and October 14. This water represented over 10 percent of the remaining water in Trinity Reservoir, already at critical low levels after four years of drought. This new low level is well below the critical end of year storage level needed to sustain flows through the winter and next year’s cold-water pool for Klamath-Trinity salmon.

The diversion from the Trinity RiverBecause Shasta’s cold-water pool has been needed over these same six weeks since September 1 (and prior to that) to cool the warm Trinity water before it is released to the Sacramento River from Keswick Reservoir, Shasta’s cold-water pool and storage has also been used for the transfers. Shasta Reservoir’s cold-water pool and storage are needed to sustain salmon through the fall, but also the entire water supply for California next year. Shasta Reservoir is now down to 1.6 MAF out of its 4.55 MAF of capacity, its lowest level since the 1991-92 and 1976-77 droughts.

These transfers also have significant effects on the Delta and its low salinity zone critical habitat for native Delta fish species, including the Delta smelt. Delta exports are the mechanism for transferring water from the north to the south. Transfers are evident in recent Delta exports. As shown in the chart below, CVP exports increased in amounts between 600-1500 cfs in September and early October in response to CVP and other transfers. Most of the extra CVP export was sourced in Shasta and Trinity reservoirs. State Water Project transfers through the Delta also occurred (see next chart).

With flows through and out of the Delta to the Bay very low in this critical drought year, such exports have higher than normal environmental effects; however, transfers are exempt from restrictions applied to project exports   Even large volumes transferred at once do not trigger additional protections from the effects of pulling more water and more fish from the Sacramento River into the central Delta. We are glad to see that Mr. Howard has at least acknowledged these impacts. During drought workshops in 2014 and 2015, CSPA objected to this free pass for transfers through the Delta for years, calling them “the phantoms of the exports.” In early 2015, Mr. Howard explicitly re-authorized their special exempt status.

CVP Exports in summer 2015

CVP Exports in summer 2015. The total “extra” export is less than the total transfer by about 20 %, because some transfer water is required to pass through to the Bay as “carriage water” to repel salinity.

SWP Exports in summer 2015. Most of the SWP transfers were in early September.

SWP Exports in summer 2015. Most of the SWP transfers were in early September.

Part 4 – Solutions to save Shasta-Trinity salmon

Posted on by

This is the last of four part series on the effects of the Shasta-Trinity Division on Sacramento and Klamath-Trinity River salmon. Part 1 introduced the problem: the failure of Reclamation to manage the Shasta-Trinity Division to protect the salmon resources of the Sacramento and Klamath-Trinity river systems. Parts 2 and 3 summarized the effects on salmon in the Sacramento River and Klamath-Trinity, respectively. In part 4, we suggest solutions to the problems.

The Reasonable and Prudent Alternative (RPA) in the NMFS 2009 Biological Opinion (NMFS OCAP BO) for operation of the federal Central Valley Project (CVP) and the State Water Project (SWP) simply does not go far enough to protect salmon resources affected by the Shasta-Trinity Division of the CVP. NMFS has concluded the RPA is all it can order, acknowledging that it is not enough in the driest years. But even in the worst years, there is much that could be reasonably done to save the salmon in both river systems, including action under Reclamation’s control and NMFS’s jurisdiction.

NMFS’s Biological Opinion states: “NMFS recognizes that the RPA must be an alternative that is likely to avoid jeopardizing listed species or adversely modifying their critical habitats, rather than a plan that will achieve recovery.”1 However, the RPA is not adequate to avoid jeopardy because the two long-term elements (reintroduction above Shasta and restoring Battle Creek) are too slow in developing. NMFS has also failed to petition the State Board to modify Water Right Order WR-90-05 to limit deliveries to Sacramento Valley Settlement Contractors in drought years, a need described in the BO. Continuing deliveries to the Settlement Contractors in summer of 2014 led directly to the loss of the 2014 Winter Run brood year.

“Providing fish passage at Shasta, Nimbus, and Folsom Dams, which ultimately is the only means of counteracting the loss of habitat needed for egg incubation and emergence, and steelhead over-summering habitat at lower elevations. This habitat loss has already occurred and will be exacerbated by climate change and increased water demands”. Habitat and CVP operations were adequate in the early 1970s, 30 years after Shasta Dam was constructed to sustain the Winter-Run population at 40 to 50 thousand spawners each year. It is the conditions below the dams that have changed to make sustaining salmon more difficult. Many of the effects are reversible through CVP operation changes and restoration of habitats below the dams. It was just over a decade ago the population had again reached 20,000 under the concerted funding and management afforded by the CVPIA and prescriptions of the previous NMFS BO.

“The effects analysis in this Opinion highlights the very challenging nature of maintaining an adequate cold water pool in critically dry years, extended dry periods, and under future conditions, which will be affected by increased downstream water demands and climate change. This suite of actions is designed to ensure that Reclamation uses maximum discretion to reduce adverse impacts of the projects to winter-run and spring-run in the Sacramento River by maintaining sufficient carryover storage and optimizing use of the cold water pool.” Reclamation has not used maximum discretion, and thus has not maintained sufficient carryover storage in Shasta or Trinity reservoirs and has failed miserably at managing the cold-water pools in both reservoirs.

There are many instances where Reclamation has misrepresented its abilities and intentions and has inadequately portrayed its underlying reasons for taking specific actions in the operation of the Shasta-Trinity Division. Its primary objective has been to meet the water demands of contractors and to generate the maximum amount of peaking power possible from the Division’s many hydropower plants.

“The effects analysis in this Opinion, and supplemental information provided by Reclamation, make it clear that despite Reclamation’s best efforts, severe temperature-related effects cannot be avoided in some years. The RPA includes exception procedures to deal with this reality. Due to these unavoidable adverse effects, the RPA also specifies other actions that Reclamation must take, within its existing authority and discretion, to compensate for these periods of unavoidably high temperatures. These actions include restoration of habitat at Battle Creek that may be support a second population of winter-run, and a fish passage program at Keswick and Shasta dams to partially restore winter-run to their historical cold water habitat.” The severe temperature related effects on the Sacramento and Klamath-Trinity rivers can be avoided by better balancing the water supply between contractor water demands, peaking power generation, and salmon.

5-mile reach between Redding and Keswick Dam

The BO allows sustaining Winter Run spawning to only the 5-mile reach between Redding and Keswick Dam in drought years like 2014 and 2015. Even in these years salmon were not protected in this minimal reach. (Map Source)

“An RPA must avoid jeopardy to listed species in the short term, as well as the long term.   Essential short-term actions are presented for each division and are summarized for each species to ensure that the likelihood of survival and recovery is not appreciably reduced in the short term (i.e., one to five years).  In addition, because the proposed action is operation of the CVP/SWP until 2030, this consultation also includes long-term actions that are necessary to address project-related adverse effects on the likelihood of survival and recovery of the species over the next two decades.”   The RPA prescribed in the NMFS BO obviously is inadequate to avoid jeopardy especially in the short term.  The following are further actions necessary to avoid jeopardy.

Reduce Reservoir Releases Designed to Meet Contractor Water Demands

Reclamation, NMFS and the State Board must reduce Shasta and Trinity reservoir releases to meet downstream water demands.  They have instead adopted the illegal and ineffective strategy of  weakening standards to satisfy demands during the present four-year drought, and salmon have gone unprotected.  Redistribution of water demands via use of spring and fall water transfers in the Central Valley has generally aggravated the problem by adding to water demands from August through November when cold water pools in reservoirs are limited.  Transfers are a further burden because of the need to add carriage water.  Export of Trinity water to the Sacramento River to meet contractor demands places a burden on both the Trinity and Shasta cold water pools.  Target end-of-September “safe” carryover storage levels have not been achieved in 2014 or 2015 at either Shasta or Trinity reservoirs.

Changes in Hydropower Operations

The Shasta-Trinity Division produces a lot of “green” energy through hydropower.  Having Lewiston and Keswick reservoirs below Trinity and Shasta reservoirs further allows hydro-peaking to meet daily patterns of electricity demands.  The two-step drop for Whiskeytown transfers from the Trinity to the Sacramento adds even more potential peaking power.  Trinity Reservoir water drops from a 2200-2400 ft elevation to 1900-ft at Lewiston Reservoir, to 1200-ft at Whiskeytown, to 600-ft at the Spring Creek Powerhouse on Keswick Reservoir providing a substantial potential for peaking hydropower.

Our analysis of operational data shows that peaking power generation leads to added heating of Lewiston, Whiskeytown, and Keswick reservoirs, and added loss of cold water pools from Shasta and Trinity.  Afternoon peaking generation pulls warmer water into penstocks than nighttime generation.  Generating more at night reduces the loss of cold water pools, but at the expense of the high-value peak power.  No mention of this option is included in the NMFS BO RPA.

The RPA does include Reclamation’s ability to bypass the hydropower systems at both Shasta and Trinity dams and releasing cold water via the lower level outlets.  The option was not employed effectively in 2014 or 2015 at either dam.

Installation of temperature control devices and temperature curtains at reservoir inlets to the hydropower systems has proven beneficial but not totally effective.  Planned improvements should be immediately implemented.  The Shasta Temperature Control Devise proved ineffective in late summer 2014.  The Whiskeytown temperature curtain fails to reduce water temperatures in water released to Keswick Reservoir below 58°F, thus requiring the added release of Shasta cold water pool to meet the 54-56°F required release from Keswick Reservoir to the Sacramento River.

Summary of Potential Measures

Changes in the operation of the Shasta-Trinity Division of the Central Valley Project in the following are necessary to preserve Sacramento and Trinity River salmon:

  1. Provide a better balance between water supply demands, hydropower production, and salmon needs.
  2. Improve management of reservoir storage, especially the amount of cold-water pool in reservoir storage
  3. Better manage the distribution of reservoir releases between power turbines (warmer) or lower level bypasses (colder)
  4. Improve the daily pattern of reservoir releases to meet peaking power demands for electricity while minimizing demands on reservoir coldwater pools.
  5. Improve blending capabilities in reservoir outlets to power turbines (Shasta has a Temperature Control Devise that allows pulling water from different lake levels)
  6. Improve water temperature mixing in the two re-regulating reservoirs (Keswick below Shasta and Lewiston below Trinity)
  7. Improve water temperature management of releases to the Sacramento and Trinity Rivers (do not relax water temperature standards)
  8. Better manage the export of Trinity Reservoir water via Lewiston and Whiskeytown reservoirs to Keswick Reservoir (to Sacramento River) to minimize the use of Shasta’s cold water pool to cool water originating in the Trinity .
  9. Truly address the NMFS BO RPA goals and objectives for the near-term:

“In the near term, adverse effects of project operations to winter-run will be reduced primarily through the following measures:  Modifications to Shasta reservoir management will result in more reliable provision of suitable water temperatures for spawning and egg incubation in the summer months.  The new year-round Shasta management program is expected to minimize frequency and duration of temperature related egg mortality in dry and critically dry years, thus reducing, though not eliminating, the population level stress of these temperature related mortalities.  The new Shasta program will allow for an expanded range of habitat suitable for spawning and egg incubation in wetter year types (i.e. through meeting downstream compliance points more often).  Over time, this will help to preserve diversity of run-timing and decrease the risk of a single event in a localized area causing a population level effect.  Temperature related effects on winter-run will persist into the future, and cannot be fully off-set through Shasta reservoir storage actions, due to physical and hydrological constraints on the CVP system, and the delivery of water to non-discretionary CVP contractors (e.g. Sacramento River Settlement Contractors).  Given a fixed supply of cold water in any given year starting in May, as an overall strategy, the RPA prioritizes temperature management in favor of winter-run due to their endangered status and complete dependence on suitable habitat downstream of Keswick for their continued survival.”

  1.   All italicized quoted text in this post is from the NMFS OCAP Biological Opinion. ↩

Part 3 – Trinity River Salmon

Posted on by

This is part 3 of a four-part series on the effects of the Shasta-Trinity Division on Sacramento and Trinity-Klamath salmon. Part 1 is an introduction to the series. Part 2 is a discussion of the effects of the Shasta-Trinity Division on Sacramento River salmon. Part 3 is a discussion of the effects of the Shasta-Trinity Division operation on Trinity-Klamath salmon.

Operations of the Shasta-Trinity Division affects Trinity River salmon as well as salmon in the lower Klamath River downstream of the mouth of the Trinity River. The main effect on the Trinity-Klamath salmon comes from the export of approximately half of Trinity Reservoir’s inflow to the Sacramento River, resulting in lower Trinity storage. This in turn may cause lower Trinity-Klamath flows and higher water temperatures in the Trinity River and lower Klamath.

National Marine Fisheries Service (NMFS) is in the process of conducting a separate consultation on the effects of the Shasta-Trinity Division operations on listed Coho salmon in the Trinity River. NMFS is committed to ensuring appropriate coordination between the analysis and results of Sacramento Winter Run Opinion and the forthcoming Coho opinion. The NMFS OCAP BO RPA1 will be analyzed in the Trinity Coho Opinion, and the OCAP BO may be adjusted as necessary to avoid jeopardy to Trinity-Klamath Coho salmon and adverse modification of their critical habitat.

The biggest threat to Trinity salmon results from the drawdown of Trinity Reservoir as Trinity water is exported to the Sacramento River. Without adequate carryover storage, Trinity reservoir cannot be counted on to provide sufficient cold-water flow to the Trinity and lower Klamath Rivers. Without a sufficient cold water pool in Trinity Reservoir, warm water from the reservoir can threaten the Trinity, Lower Klamath, and Sacramento River salmon. While the large die-off of salmon in the lower Klamath in 2002 may not be directly attributable to low warm water flows to the upper Trinity River below Lewiston Reservoir, pulses of cold water from Trinity Reservoir in late summer under conditions like 2002 have averted similar die-offs in 2014 and 2015. Pulses of cool water released from Trinity Reservoir continue this month despite unsuccessful attempts by Central Valley water contractors to stop that action. So far, the cold water pool in Trinity Reservoir appears adequate to save Trinity and Klamath River this year despite its ongoing depletion by exports to the Sacramento River. Approximately three quarters of the water released from Trinity Reservoir this summer has gone to the Sacramento River.

Trinity Reservoir storage in acre-feet over the past three years.

Trinity Reservoir storage in acre-feet over the past three years.

Trinity Reservoir water export to Sacramento River via Whiskeytown Reservoir summer 2015.

Trinity Reservoir water export to Sacramento River via Whiskeytown Reservoir summer 2015.

Trinity Reservoir water released to Trinity River from Lewiston Reservoir summer 2015. Note recent flow releases to flush and cool the lower Trinity and Klamath.

Trinity Reservoir water released to Trinity River from Lewiston Reservoir summer 2015. Note recent flow releases to flush and cool the lower Trinity and Klamath.

Temperature of water released from Lewiston Reservoir in spring-summer 2015.

Temperature of water released from Lewiston Reservoir in spring-summer 2014.

Temperature of water released from Lewiston Reservoir in spring-summer 2015.

Temperature of water released from Lewiston Reservoir in spring-summer 2015.

  1.  The Reasonable and Prudent Alternative(s) in the National Marine Fisheries Service’s Biological Opinion for the long term Operations and Criteria Plan for the State Water Project and the Central Valley Project. ↩