Water Resources Research Act Program

Details for Project ID 2010AK87B

The diminishing role of glacier runoff into Eklutna Lake: potential impacts on hydropower and water supply for the Municipality of Anchorage (year 2 renewal)

Institute: Alaska
Year Established: 2010 Start Date: 2010-03-01 End Date: 2011-02-28
Total Federal Funds: $13,670 Total Non-Federal Funds: $33,911

Principal Investigators: Michael Loso

Abstract: I propose to continuean existing study of the impacts of ongoing climatic changes on the glacier runoff contribution to Eklutna Lake. The existing study includes work funded by NIWR in the previous fiscal year and successfully completed by Alaska Pacific University faculty, graduate students, and undergraduates (see companion progress report: Loso 2009). Anchorage, the largest city in Alaska, is critically dependent upon the waters of Eklutna Lake for both drinking water (~80% of the city’s supply) and hydropower generation (10-15% of the city’s supply). Eklutna Lake is glacier-fed and has retreated dramatically over the last 50 years, losing approximately 1.5 km3 of ice. Impacts of this ongoing glacier retreat include the short-term provision of additional meltwater to the Eklutna Lake, but over the longer term will likely include a reduced contribution of meltwater during the mid-summer when Municipal demand for water and power peaks. Additional glacier-mediated changes to the temperature and sediment load of the lake’s inlet stream appear to have already altered the density-driven stratification of the lake with implications for water treatment and reservoir volume.The work proposed here will be led by the same two graduate students who worked on this project last year. Both are scheduled to complete their theses during the performance period of this grant, and a virtue of funding their continued work on this project (aside from the obvious benefit of gaining an additional year of data) is the ability it provides them to incorporate their experience with this logistically difficult work into improved field techniques that will benefit our research over the long-term. One student, focused on the glacier, will continue the mass balance and velocity measurement program. The second student, focused on hydrology, will continue a time-series of water and sediment discharge on East and West Forks of Eklutna River. Support is requested primarily for graduate student salary and logistical expenses; mentoring will be provided by research collaborators from Alaska Pacific University, US Geological Survey, the Anchorage Water and Wastewater Utility, and Municipal Light and Power.