Effectiveness of Water Release as Mitigation for Hydroelectric Impacts to Fish

Since the early 1980s, a water temperature management program has been in existence on the Nechako River system in central British Columbia, Canada. The program releases water based on anticipated meteorological conditions in an attempt to prevent temperature from exceeding a specified threshold of 20°C downstream during a period when spawning migrations of sockeye salmon Oncorhynchus nerka are in the Nechako River. Since the inception of the program, this threshold has been exceeded only rarely; however, the variables that influence water temperature and that are used to manage water releases in the Nechako River watershed have not been subject to an independent analysis. Increasing demand for water at other times of year and a desire to restore a more natural hydrograph to the river to meet other ecological demands have impelled this analysis. A principal components analysis that examined the factors contributing to river temperature demonstrated that the summer controlled flow releases accounted for 24% of the temperature variability and were probably a factor in maintaining compliance with the program's temperature threshold. Furthermore, during most summers, the Nechako River provided a cooling influence to input from the Stuart River tributary in a downstream reach that is used by the majority of the migrating sockeye salmon. Water temperature has a modest influence on prespawning mortality (up to 22% of the variability), suggesting that attempts to reduce summer water temperatures through releases in the upper Nechako River watershed can mitigate against poor spawning success of sockeye salmon populations that migrate through the lower reaches of the system. Received April 19, 2011; accepted December 9, 2011

show abstract

scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.

Contact Info

customersupport@researchsolutions.com

10624 S. Eastern Ave., Ste. A-614

Henderson, NV 89052, USA

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Blog Terms and Conditions API Terms Privacy Policy Contact Cookie Preferences Do Not Sell or Share My Personal Information

Made with 💙 for researchers

Part of the Research Solutions Family.

Effectiveness of Water Release as Mitigation for Hydroelectric Impacts to Fish

Cited by 2 publications

References 1 publication

Undamming Rivers: A Review of the Ecological Impacts of Dam Removal

Undamming Rivers: A Review of the Ecological Impacts of Dam Removal

The Efficacy of Reservoir Flow Regulation for Cooling Migration Temperature for Sockeye Salmon in the Nechako River Watershed of British Columbia

Contact Info

Product

Resources

About