Delta Passage Model:A quantitative framework for integrating and

understanding water project effects on migrating salmon

Funded byMetropolitan Water District of Southern California

Oregon • California • Washington • Idaho • Alaska www.fishsciences.net

Introduction to Chinook Salmon Delta Passage Model

• Habitat, predators and flow conditions influence survival among emigrating juvenile salmon

• Despite importance of Delta salmon survival and a wealth of excellent studies, biologists and managers lack tools capable of integrating and illustrating patterns of salmonid behavior in relation to flow conditions and water project operations

Introduction to Chinook Salmon Delta Passage Model

The core purpose of the Delta passage model… • to provide a common, transparent framework

upon which knowledge may be integrated and displayed.

• to serve as a “blackboard” upon which alternative hydrologies, water project operations, and fish behaviors may be evaluated• document ESA compliance • evaluate water project alternatives• identify areas of critical uncertainty requiring further

study

Findings from numerous CWT and acoustic tag studies have been incorporated into our model’s migration and survival functionality

Kjelson and Brandes (1989)Baker et al. (1995)

Brandes and McLain (2001)Newman and Rice (2002)

Newman (2003, 2008), Kimmerer (2008)

Vogel (2008)Perry and Skalski (2008)

Also VAMP Studies, North Delta Hydrodynamic and Juvenile Salmon Migration Studies, California Fish Tracking Consortium

Introduction to Chinook Salmon Delta Passage Model

What’s in the Delta Passage model?

• Model built using system dynamic software GoldSim• Model simulates migration and mortality of juvenile

Chinook salmon entering the Delta form the Sacramento, Mokelumne, and San Joaquin Rivers

• Model operates on a daily step• Flows and fish behavior simulated for 10 reaches and

five reach junctions

What’s in the Delta Passage model?

• Fish behavior and mortality modeled probabilistically using empirical observations

• Constant or daily input values for

• For each user defined scenario, 100 Monte Carlo simulation are generated– Providing estimates of salmon survival to Chipps Island and

confidence intervals

• Sacramento River flow• Mokelumne River flow• San Joaquin River flow• Exports

• DCC position• Yolo Bypass flow• Flow Diversion at Hood

Sacramento Inflow

Mokelumne Inflow

San Joaquin Inflow

Next, smolts are delayed in the “Reach_Migration” element to mimic the time it takes for smolts to migrate through the reach.

Delta Passage Model: What next?

• Model is ready to conduct runs with flow and water project operation provided by CalSim (or any other source)

• Model will evolve over time as experts continue review, results are analyzed, and new studies and analyses become available– Not a static product

• Looking for opportunities to apply this model!

Oregon • California • Washington • Idaho • Alaska www.fishsciences.net