Evaluation of a Prototype Surface Flow Bypass for Juvenile Salmon and Steelhead at the Powerhouse of Lower Granite Dam, Snake River, Washington, 1996-2000

Journal Article · Mon Feb 28 04:00:00 EST 2005 · North American Journal of Fisheries Management

DOI:https://doi.org/10.1577/M04-024.1· OSTI ID:15020531

Johnson, Gary E; Anglea, Steven M; Adams, Noah S; Wik, Timothy O

A surface flow bypass provides a route in the upper water column for naturally, surface-oriented juvenile salmonids to safely migrate through a hydroelectric dam. Surface flow bypasses were recommended in several regional salmon recovery plans as a means to increase passage survival of juvenile salmonids at Columbia and Snake River dams. A prototype surface flow bypass, called the SBC, was retrofit on Lower Granite Dam and evaluated from 1996 to 2000 using biotelemetry and hydroacoustic techniques. In terms of passage efficiency, the best SBC configurations were a surface skimmer (99 m3/s [3,500 cfs], three entrances 5 m wide, 5 m deep and one entrance 5 m wide, 15 m deep) and a single chute (99 m3/s, one entrance 5 m wide, 8.5 m deep). They each passed 62 ? 3% (95% confidence interval) of the total juvenile fish population that entered the section of the dam with the SBC entrances (Turbine Units 4-5). Smooth entrance shape and concentrated surface flow characteristics of these configurations are worth pursuing in designs for future surface flow bypasses. In addition, a guidance wall in the Lower Granite Dam forebay diverted the following percentages of juvenile salmonids away from Turbine Units 1-3 toward other passage routes, including the SBC: run-at-large 79 ? 18%; hatchery steelhead 86%; wild steelhead 65%; and yearling chinook salmon 66%. When used in combination with spill or turbine intake screens, a surface flow bypass with a guidance wall can produce a high level (> 90% of total project passage) of non-turbine passage and provide operational flexibility to fisheries managers and dam operators responsible for enhancing juvenile salmonid survival.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 15020531
• Report Number(s): PNNL-SA-39906; 400480000
• Journal Information: North American Journal of Fisheries Management, Journal Name: North American Journal of Fisheries Management Journal Issue: 1 Vol. 25
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
13 HYDRO ENERGY
Columbia River
DAMS
EFFICIENCY
EVALUATION
FISHERIES
FLEXIBILITY
GRANITES
JUVENILES
Lower Granite Dam
RIVERS
SALMON
SCREENS
SHAPE
SKIMMERS
Snake River
TURBINES
U.S. Army Corps of Engineers
WATER
biotelemetry
hydroacoustics
juvenile salmonids
salmon
surface flow bypass