Feasibility of Adaptively Managing Reclamation's Klamath Project Reservoirs to Provide Suitable Water for Endangered Species, Refuges, Tribal Trust Assets, and Agriculture
* Is there a correlation between Klamath Project water operations and associated water levels in supply reservoirs and river flows, water suitability, meteorological conditions, and fish survival?
* Is it feasible to manage lake levels and river flows for water suitability and water delivery?
Need and Benefit
Managing water elevations at Upper Klamath Lake (UKL), Oregon is one of the most controversial issues for Reclamation's Klamath Project. Water stored in UKL is used to meet Reclamation's legal and contractual obligations for agricultural supply, endangered species, waterfowl refuges, and Native American Tribal trust assets. Water supplies for irrigated agriculture were severely curtailed in 2001 to maintain high lake levels for protecting endangered suckers in UKL and higher river flows for threatened coho salmon in the Klamath River. However, in 2002 the Federal Government asked the National Research Council (NRC) to review the data and analytical effort that were used to support the higher lake levels and river flows in 2001. NRC concluded that there was no clear connection between water level in UKL and conditions that are adverse to the welfare of the endangered suckers or increased flows in the Klamath River main stem for coho salmon. The principal populations of the federally listed endangered Lost River and shortnose suckers endemic to shallow UKL are subject to periodic catastrophic and annual localized mortality events caused by a combination of factors that include high levels of unionized ammonia, pH, and critically low levels of dissolved oxygen (DO). From 1995 to 1997, three major die-offs killed a substantial portion of the adult population. We are at present unable to predict or prevent such events. It is crucial to determine what role project management of UKL has on the mechanisms that cause adverse water suitability, and ultimately in finding solutions that will allow Reclamation to avoid or reduce catastrophic sucker mortality events and at the same time provide acceptable water delivery downstream.
Phase 1 of this research will entail using a risk assessment model designed to predict the possible percentage (spatial acreage) of the lake that might be impacted by critically low DO at dawn given the distribution of observed DO levels at dusk. The model is designed to incorporate reservoir stage to determine potential acreage affected under differing operational levels. The model is not designed to predict which areas of the reservoir are most susceptible to critically low DO at dawn, though possibly a sub-model could be built to do this. Spatial heterogeneity is averaged out via the monte-carlo simulation. The model is generalized and will provide directionality. A sensitivity analysis of each parameter will allow identifying which parameters are most critical to model operation.
Phase 2 will verify and determine feasibility of using the model as a tool for assessing impacts of water level management on water suitability for endangered fish in UKL. Also, a project-wide water suitability monitoring plan would be developed. This activity is intended to meet Reclamation's Endangered Species Act (ESA) requirements identified by the U.S. Fish and Wildlife Service (FWS) in the 2002 Biological Opinion. Results of the risk assessment model will aid in developing linkages between modeling outputs and decision support systems for managing water resources and would have broad application to other hypereutrophic reservoirs. Developing the monitoring plan would provide information to be used for adaptive management in avoiding future fish kills and improving water delivery reliability in the Klamath Project.
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This information was last updated on March 31, 2015
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