Asking the Fish: Using Acoustic Telemetry Data (2008-2012) to Identify Safest Operating Conditions for Juvenile Salmonid Passage at Bonneville Dam

The USACE Turbine Survival Program, using field studies, laboratory studies, and physical and numerical hydraulic models, has been working to identify the best operating conditions for juvenile salmonids passing through turbines at USACE hydroelectric projects to reduce injury and mortality.  Additionally, there have been questions relative to spillway survival at Bonneville Dam (BON).  Recent survival studies have indicated that survival through the spillway is lower than other passage routes possibly due to structural erosion at several spill bays or accumulation of rock below the splillway.

From 2008 through 2012, acoustic telemetry studies were conducted at BON to evaluate fish passage behavior and survival.  Although the primary purpose of these studies was to estimate survival and passage behavior additional processing and analysis of these large datasets can be used to answer other relevant management questions.   Using these multi-year datasets, we evaluated survival of juvenile salmon passing through the turbines at BON over the turbine operating ranges to determine if there were survival differences in the 1% peak efficiency range and up to the generator limit.  We also estimated spillway survival to determine if lower passage survival could be attributed to certain regions of the spillway due to erosion or other factors.