November 12, 2002
Report

Optimization of Hydroacoustic Deployments at John Day Dam

Abstract

This report describes short-term studies conducted in late November and early December 2001 to optimize hydroacoustic sampling techniques for John Day Dam before the 2002 fish passage efficiency (FPE) study. Knowledge gained in this study should significantly improve hydroacoustic sampling and the accuracy of estimates of fish passage at two locations that have presented problems in past studies. The spillway has been most problematic because many fish detected there were not entrained. Without correction, non-commitment of fish can result in multiple detections and overestimation of fish passage and FPE. Trash-rack-mounted, down-looking transducers for sampling unguided fish at a submerged traveling screen (STS) also have posed problems because the beam was aimed so far downstream that researchers had concerns about fish aspect and detectability. The deployments, aiming angles, and ping rates described here should eliminate all problems encountered in previous studies. This report describes hydroacoustic evaluations. The spill-bay deployment identified in this study should completely eliminate multiple detections of fish by limiting the sample volume for counting fish to the deep high-discharge volume adjacent to the gate. Results from testing of transducers deployed in a turbine intake with an STS suggest that, after testing in 2002, it may be possible to cut the number of powerhouse transducers sampling STS units by 50% or to double the spatial sampling coverage with the same number of transducers, all while improving detectability.

Revised: September 21, 2007 | Published: November 12, 2002

Citation

Ploskey G.R., C.B. Cook, P.S. Titzler, and R.A. Moursund. 2002. Optimization of Hydroacoustic Deployments at John Day Dam Richland, WA: Pacific Northwest National Laboratory.