Water Quality Analysis Support for Hydroelectric Projects

Overview

Water quality analysis is a key component of fish survivability and passage improvements. Hydroelectric projects across the Federal Columbia River Power System (FCRPS) rely on robust water quality analysis for decision making and compliance strategies. Furthermore, changing environmental conditions, aging infrastructure, and increased water demand increase the need for technically accurate and statistically rigorous assessments.

Our Role

Four Peaks provides technical support for water quality analysis, including temperature and total dissolved gas (TDG), for multiple utility clients within the FCRPS. In one location, we evaluated the effect of TDG on juvenile salmonids transported in barges downstream on the Columbia and Snake rivers. As part of this study, water pumped from hydroelectric projects served as the source water to imprint juveniles. The juveniles were then held in raceways adjacent to the tailrace and transported downstream in barges. Four Peaks evaluated the accuracy of the current TDG data collection methods and possible monitoring alternatives. We then assessed the effects of TDG control measures and the barge holding environment on juveniles. Four Peaks reported on the results, which the client incorporated into the ongoing water management strategy for this project.

In another project, Four Peaks staff evaluated the efficacy of a temperature control structure installed in a Washington hydroelectric facility. Due to record setting water temperatures at the time, a thermal barrier inhibited passage of migrating salmonids through the fish ladder. The client proposed a cooling system to lower the water temperature in the forebay in the vicinity of the adult fish ladder exit. Four Peaks staff evaluated the temperature changes from the temperature control spray in the forebay compared to potential migration paths for salmonids.