Sluiceway Operations to Pass Juvenile Salmonids at The Dalles Dam, Columbia River, USA

Abstract

Existing ice and trash sluiceways are commonly used as benign, nonturbine routes for downstream passage of juvenile salmonids at hydropower dams. At The Dalles Dam on the Columbia River, we studied various operational configurations of sluiceway weirs to maximize sluiceway passage of juvenile Pacific salmon Oncorhynchus spp. and steelhead O. mykiss. We applied hydroacoustic methods to compare fish passage rates and sluiceway efficiencies for two weir configurations in each year: three weirs (SL 1; i.e., collectively referring to the three weirs above main turbine unit [MU] 1) versus six weirs (SL 1+18) during 2004; and middle (SL 2+5) versus east (SL 2+19) powerhouse weir locations during 2005. Horizontal distributions at the sluiceway and turbines and the effects of operating turbines beneath open sluiceway gates were also analyzed. Sluiceway passage efficiency relative to the powerhouse (SLYphs) varied between study years, between spring and summer, and between day and night. In 2004, sluiceway passage rates were significantly higher (P = 0.0003) for SL 1+18 than for SL 1 during summer–night but were not significantly different between the two configurations during the other three season–day/night periods. The SLYphs was significantly higher for SL 1+18 than for SL 1. The location comparison during 2005 revealed no significant differences between the SL 2+5 and SL 2+19 configurations, except for summer–day. The experimental findings led to recommendations for long‐term operations of The Dalles Dam sluiceway: open six rather than three sluiceway weirs to take advantage of the maximum hydraulic capacity of the sluiceway; open the three weirs above the westernmost operating MU and the three weirs at SL 8, where turbine passage rates are relatively high; operate the MUs below open sluiceway weirs as a standard procedure; operate the sluiceway 24 h/d year‐round to maximize its benefits to juvenile salmonids; and use the same weir configuration year‐round. These operational concepts are transferable to dams where sluiceway surface flow outlets are used to protect downstream‐migrating fishes.Received July 19, 2012; accepted June 26, 2013

Passage and Survival of Juvenile Salmonid Smolts through Dams in the Columbia and Snake Rivers, 2010–2018

“…With the installation of weirs, sluiceways, and bypass screens and greater emphasis on spillway passage, systemwide FPE values have improved since the 1990s (Johnson et al 2013). The 1994 FCRPS biological opinion (NMFS 1994) specified an FPE target of at least 0.8 for all dams in the FCRPS.…”

“…Early structural enhancements included the construction of juvenile bypass systems (JBS), which use screens and other structures to direct fish that enter the powerhouse out of the path of turbines (Matthews et al 1977; Harmon and Park 1980; Raymond and Sims 1980). In the early 2000s, existing bypass structures were further improved (Ferguson et al 2007) and resources were shifted to the construction and enhancement of surface flow outlets such as sluices, weirs, and the corner collector at Bonneville Dam (Whitney et al 1997; Odeh 2000; Johnson et al 2013). Properly designed surface flow structures encourage nonpowerhouse passage and reduce forebay residence time (Johnson and Dauble 2006; Ploskey et al 2006; Li et al 2018).…”

Evaluation of Juvenile salmon passage and survival through a fish weir and other routes at Foster Dam, Oregon, USA

“…There is a need to balance the tradeoffs between water management and fish passage and survival at hydropower dams (Ferguson et al, 2005; Johnson et al, 2013). With respect to optimal pool elevation for operating the fish weir at Foster, fish passage over the weir was generally highest during high pool; therefore, it would be tempting to operate the weir at high pool as much as feasible.…”

“…Spillway operations can create increased levels of total dissolved gas in the river downstream of the dam (Adams et al, 2014) and shear environments as fish pass through the spillway into the tailrace of the dam (Geist et al, 2018). In addition, managers of hydropower dams must balance water availability with power generation and other uses, such as spill for fish passage (Ferguson et al, 2005; Johnson et al, 2013). One approach to enhancing spillway operations for fish passage is to retrofit selected spill bays with surface spill weirs that are designed to pass less water yet still provide a safe route for fish (Adams et al, 2014; Johnson & Johnson, 2000; Sweeney et al, 2007).…”

Rapture facilitates inexpensive and high-throughput parent-based tagging in salmonids

“…Previous challenges associated with SNPs in forensic analysis, such as needing high concentrations of DNA for sequencing, are no longer relevant [36]. SNP-based genotyping methods include whole genome sequencing, reduced representation sequencing such as restriction-site associated DNA (RAD) sequencing, Amplicon sequencing (e.g., Genotyping-in-Thousands), SNP chips, and PCR assays (e.g., SNP Type or Taqman) [34,[37][38][39][40][41][42]. Parent-based tagging (PBT) is a method of genetic tracking that can use any of these technologies to identify the offspring of specific individuals (e.g., hatchery broodstock) from genetic information [29,30,[32][33][34][35].…”