Species | Red Bluff Diversion Dam | Tisdale RST | Knights Landing RST | Sac Trawl (Sherwood) | Chipps Island Trawl | Salvage |
|---|---|---|---|---|---|---|
Chinook, LAD Winter-run, Unclipped | 99% | 98% | 98% | 58% | 12% | 42% |
Chinook, DNA Winter-run, Unclipped (Water Year) | 40% |
Assessment for Delta Operations on Salmonids
Last updated: Monday, March 02, 2026 at 3 PM
For more detailed data on salmonid conditions in the Delta see corresponding webpage on SacPAS.
Executive Summary
Entrainment management season is active.
Annual Loss: 4 (0.03% of annual loss threshold) natural winter-run, 0 (0.00% of annual loss threshold) hatchery winter-run, 182 natural steelhead, 830 (13.6% of annual loss threshold) hatchery steelhead, and 1055 (48.00% of annual loss threshold) spring-run surrogates.
Single-year Incidental Take Limit (ITL) Status: 4 (0.07% of 5,922 ITL) natural winter-run; 0 (0.00% of 1,301 ITL) hatchery winter-run; 182 (3.44% of 5,294 ITL) natural steelhead.
Spring-run surrogate yearlings (0.5% ITL per experimental release group): Group 1: 0 (0% of 376 ITL); Group 2: 257 (84.64% of 304 ITL); Group 3: 35 (12.26% of 286 ITL).
LAD winter-run presence in the Delta is high based on historical monitoring.
Steelhead presence in the Delta is high based on historical monitoring.
Natural Winter-run Chinook
Juvenile Production Estimate
The Juvenile Production Estimate for winter-run is 1,057,452 for the current water year.
Current Status
Delta Entry Timing - Historically, as of Mar 01, 58% of length-at-date (LAD) winter-run have entered the Delta based on Knights Landing RST catch, 12% have exited the Delta based on Chipps Island Trawl Catch, and 40% of DNA confirmed winter-run have been salvaged.
Red Bluff Diversion Dam Passage Estimate - As of Feb 23 estimated passage to date of LAD winter-run at Red Bluff Diversion is approximately 4.17 million fish. Note that outmigration timing overlaps with spring-run migrating fish, and true winter-run abundance likely differs from these estimates.
Delta Monitoring - Total catch of LAD winter-run at RSTs at Delta Entry (Tisdale, Knights Landing, Lower Sacramento River) between Feb 16 and Feb 22 is 10 individuals. Total catch at Sacramento Trawl and Beach Seines in the delta between Feb 17 and Mar 01 is 41 individuals. Total catch at Delta Exit at Chipps Island between Feb 17 and Feb 27 is 11 individuals.
Annual Loss
The annual loss threshold for natural winter-run is 1% of the JPE or 10,575 fish. The single-year incidental take limit (ITL) is 0.56% of the JPE (5,922 fish) or 0.36% on a 3-year rolling average (BiOp Table 184). As of March 01, cumulative loss of genetically confirmed winter-run is 4 or 0.03% of the annual loss threshold. Cumulative loss in the past 7 days has been 0.
STARS
The Delta STARS Model is an individual-based simulation model that predicts survival, travel time, and routing of juvenile salmon migrating through the Sacramento–San Joaquin River Delta. This model gives insight into survival and routing patterns of winter-run based on most current conditions.
As of March 01, overall through delta STARS estimated survival probability (with 80% credible intervals) is 0.73 (0.67-0.79) placing it in the 80th percentile of historical STARS survival estimates for the month of March (WYs 2018-2025). STARS estimated routing and survival probabilities (with 80% credible intervals) into the interior delta are 0.06 (0.05-0.08) and 0.68 (0.57-0.79), respectively, corresponding to the 14th and 75th percentiles of historical March estimates (WYs 2018-2025).
Hatchery Winter-run Chinook
Hatchery Releases
Livingston Stone National Fish Hatchery released a total of 466,344 winter-run Chinook salmon (February 18). All fish were 100% CWT-marked production fish released at the Sacramento River at John F. Reginato River Access. Release details are shown in the table below and available on SacPAS.
Release Date | Hatchery | Release Site | Release Type | Fish Released | % CWT Marked | CWT Tagcodes |
|---|---|---|---|---|---|---|
February 18, 2026 | Livingston Stone NFH | Sacramento River at John F. Reginato River Access | Production | 466,344 | 100% | 053800 056770 056788 056789 |
Juvenile Production Estimate
The Juvenile Production Estimate for hatchery winter-run is 130,096 for Livingston Stone releases. The annual loss threshold is 1% of the JPE (1,301 fish), which is the same as the single-year ITL (BiOp Table 184).
Annual Loss
As of March 02, cumulative loss of Livingston Stone hatchery fish is 0 or 0.00% of the annual loss threshold (which equals the single-year ITL). Cumulative loss in the past 7 days has been 0.
Natural-origin Central Valley Steelhead
Current Status
Delta Entry Timing - Historically, as of Mar 01, 47% of CCV steelhead have entered the Delta based on Knights Landing RST catch, 36% have exited the Delta based on Chipps Island Trawl Catch, and 28% have been salvaged.
Species | Chipps Island Trawl | Knights Landing RST | Red Bluff Diversion Dam | Sac Trawl (Sherwood) | Salvage | Tisdale RST |
|---|---|---|---|---|---|---|
Steelhead, Unclipped | 36% | 45% | 2% | 47% | 28% | 44% |
Delta Monitoring - Total catch of unclipped steelhead at RSTs at Delta Entry (Tisdale, Knights Landing, Lower Sacramento River) between Feb 16 and Feb 22 is 6 individuals. Total catch at Sacramento Trawl and Beach Seines in the delta between Feb 17 and Mar 01 is 0 individuals. Total catch at Delta Exit at Chipps Island between Feb 17 and Feb 27 is 0 individuals.
Annual Loss
As of March 01, cumulative loss of unclipped steelhead is 182 or 3.43% of the single-year incidental take limit (ITL). There is no annual loss threshold for natural steelhead. The single-year ITL is 5,294 juveniles or 2,319 juveniles as a 3-year rolling average (BiOp Table 184). Cumulative loss in the past 7 days has been 43.
Hatchery-origin Central Valley Steelhead
Surrogate Releases
There have been a total of 7 releases totaling 1,451,464 steelhead in Water Year 2026. JPE for the hatchery releases as of today is 610,752 based on estimated survivals using forecasted water year types (see details in table below). The annual loss threshold, equal to 1% of the JPE, is currently 6,108, but is subject to change with additional steelhead releases.
Hatchery | Date of Release | Number Released | Estimated Survival | Juvenile Production Estimate |
|---|---|---|---|---|
NIM | 2025-11-10 | 233,109 | 72% | 167,838 |
Coleman | 2025-12-15 | 555,720 | 38% | 211,174 |
Coleman | 2025-12-17 | 90,019 | 38% | 34,207 |
FRH | 2026-01-06 | 376,640 | 36% | 135,590 |
FRH | 2026-01-09 | 117,715 | 36% | 42,377 |
MOK | 2026-02-17 | 39,130 | 25% | 9,783 |
MOK | 2026-02-18 | 39,131 | 25% | 9,783 |
Hatchery | Survival Estimate | Source |
|---|---|---|
Coleman NFH | 0.205 – 0.433 | Sandstrom et al. 2020 |
Feather River Hatchery | 0.09 – 0.45 | Kurth 2013 |
Nimbus Hatchery | 0.62 – 0.83 | Brodsky et al. 2020 |
Mokelumne River Hatchery | 0.25 – 0.33 | Del Real et al. 2012 |
Total loss of hatchery-origin steelhead is 830 or 13.6% of the annual loss threshold. Note that hatchery origin of salvaged fish cannot be determined at this time and salvage is based on the assumption of similar routing and survival probabilities of individual hatchery releases.
Spring-run Chinook
Current Status
Delta Entry Timing - Historically, as of Mar 01, 5% of LAD spring-run have entered the Delta based on Knights Landing RST catch, 0% have exited the Delta based on Chipps Island Trawl Catch, and 1% have been salvaged.
Species | Red Bluff Diversion Dam | Tisdale RST | Knights Landing RST | Sac Trawl (Sherwood) | Chipps Island Trawl | Salvage |
|---|---|---|---|---|---|---|
Chinook, LAD Spring-run, Unclipped | 16% | 18% | 32% | 5% | 0% | 1% |
Red Bluff Diversion Dam Passage Estimate - As of Feb 23 estimated passage to date of LAD spring-run at Red Bluff Diversion is approximately 0.03 million fish. Note that outmigration timing overlaps with winter-run and fall-run outmigration, and true spring-run abundance likely differs from these estimates.
Delta Monitoring - Total catch of LAD spring-run at RSTs at Delta Entry (Tisdale, Knights Landing, Lower Sacramento River) between Feb 16 and Feb 22 is 62 individuals. Total catch at Sacramento Trawl and Beach Seines in the delta between Feb 17 and Mar 01 is 79 individuals. Total catch at Delta Exit at Chipps Island between Feb 17 and Feb 27 is 0 individuals.
Spring-run Surrogate Releases
A total of 805,323 spring-run surrogate fish have been released in Water Year 2026, with an estimated Juvenile Production Estimate (JPE) of 219,852 fish entering the Delta. This includes 805,323 Coleman Late-Fall Run Chinook (JPE: 219,852) released from Coleman National Fish Hatchery across 12 coded-wire tag groups. See details in table below.
Hatchery | Release Date | Type | # of CWT Fish Released | JPE | ITL (0.5%) | Confirmed Loss | CWT Codes |
|---|---|---|---|---|---|---|---|
Coleman NFH | 2025-11-13 | Production | 143,346 | 39,134 | 9 | 056808, 056809 | |
Coleman NFH | 2025-11-17 | Experimental | 75,119 | 20,507 | 376 | 0 | 056810 |
Coleman NFH | 2025-12-17 | Production | 468,876 | 128,002 | 754 | 053700, 056806, 056811, 056812, 056814, 056815, 056817 | |
Coleman NFH | 2025-12-22 | Experimental | 60,873 | 16,618 | 304 | 257 | 056813 |
Coleman NFH | 2026-01-08 | Experimental | 57,109 | 15,591 | 286 | 35 | 056816 |
Annual Loss
The annual loss threshold is 1% of the JPE entering the Delta, which equals 2,199 fish. As of March 01, cumulative loss is 1,055 fish or 48.00% of the annual loss threshold. The single-year incidental take limit (ITL) is 0.5% of the estimated number of each surrogate release group (BiOp Table 184). ITL status by experimental release group: Release Group 1 (2025-11-17): 0 loss of 376 ITL (0%); Release Group 2 (2025-12-22): 257 loss of 304 ITL (84.64%); Release Group 3 (2026-01-08): 35 loss of 286 ITL (12.26%)
Loss Prediction and Trajectories
The following figures display the current loss predictor model outputs for winter-run Chinook salmon and steelhead.
Evaluation
What is the probability of exceeding natural or hatchery winter-run Chinook salmon loss thresholds in the upcoming week?
LOW RISK: Natural winter-run cumulative loss is currently 0.03% of the threshold. LOW RISK: Hatchery winter-run cumulative loss is currently 0.00% of the threshold.
What is the probability of exceeding spring-run Chinook salmon surrogate yearling loss thresholds in the upcoming week?
LOW RISK: Spring-run surrogates cumulative loss is currently 48.00% of the threshold.
What is the probability of exceeding natural or hatchery steelhead loss thresholds in the upcoming week?
LOW RISK: Natural steelhead cumulative loss is currently 3.43% of the threshold. LOW RISK: Hatchery steelhead cumulative loss is currently 13.60% of the threshold.
References
Brodsky, A., Zeug, S. C., Nelson, J., Hannon, J., Anders, P. J., & Cavallo, B. J. (2020). Does broodstock source affect post-release survival of steelhead? Implications of replacing a non-native hatchery stock for recovery. Environmental Biology of Fishes, 103(5), 437–453.
Del Real, S. C., Workman, M., & Merz, J. (2012). Migration characteristics of hatchery and natural-origin oncorhynchus mykiss from the lower mokelumne river, california. Environmental Biology of Fishes, 94(2), 363–375.
Kurth, R. (2013). Downstream migration success of feather river fish hatchery steelhead smolts under different release strategies.
Sandstrom, P. T., Ammann, A. J., Michel, C., et al. (2020). Low river survival of juvenile steelhead in the sacramento river watershed. Environmental Biology of Fishes, 103(5), 531–541.