Evaluation of salmonid smolt survival at Roza Diversion Dam and the downstream 11-mile Reach

Project ID: 2237
Principal Investigator: Cathy Karp
Research Topic: Fish Passage and Entrainment
Funded Fiscal Years: 2012 and 2013
Keywords: managing river flows for human and fish use, salmonid smolt survival, threatened and endangered species

Research Question

How to manage dam operations and flows in the 11-mile reach below Roza Diversion Dam (Yakima River, WA) to reduce predation and increase survival of outmigrating salmonids smolts and adult steelhead?

This reach has been identified by the Systems Operations Advisory Committee (SOAC) as critical to the salmonid recovery program in the Yakima River because current minimum flow standards have created conditions in which it's believed excessive bird and fish predation occur. National Marine Fisheries Service is concerned over excess mortality to juvenile outmigrating steelhead in this reach and the impact to recovery of the upper Yakima steelhead population. The spring Chinook and coho hatchery supplementation programs in the upper Yakima River managed by the Yakama Nation are likely being impacted through excessive smolt mortality in this reach as well.

Need and Benefit

Many native fish species continue to decline in western rivers altered by dams and associated operations (e.g., flood control, storage, power generation, etc.). Determination of necessary rivers flows to sustain threatened and endangered species (T&E) is critical to reverse the ongoing declines. Reclamation is uniquely positioned to help formulate new compromises in allocation of freshwater resources between human needs and freshwater fish needs. This becomes more urgent as these resources become more limiting due to human population expansion in the western US and possible climate change predictions.

Only a few methods exist to evaluate fish passage/survival in large rivers. We will determine how to apply state-of-the-art PIT-tag technology in a highly fluctuating large river system (400-12,000 cfs; targeting flows<2000cfs). This information will be highly useful in other large western river systems with similar issues.

Contributing Partners

Contact the Principal Investigator for information about partners.

Research Products

Bureau of Reclamation Review

The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.

Summary of Initial Efforts to Research Vertical PIT-Tag Scanners for Deep Rivers (final, PDF, 713KB)
By Cathy Karp
Report completed on March 25, 2014

We began investigating the feasibility of detecting downstream migrating juvenile Chinook salmon smolts using full-duplex PIT tag technology.

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Last Updated: 6/22/20