Projected Sulfate Redistribution As Impacted by Lake Level Stabilization Scenarios: Devils Lake, North Dakota

Abstract

Devils Lake, a terminal, saline lake, of glacial origin, in North Dakota has experienced a 7.5 m rise in lake elevation resulting in the flooding of over 243km2 from 1992 to 2002. At lower water surface elevations, Devils Lake functions as a series of connected basins with salinity increasing in an eastward direction due to evaporation. The recent increase in water depth provides an opportunity for increased dispersive exchange flows and mixing between the lake’s basins due to wind and buoyancy forces. This increased mixing will change the future water quality distribution in Devils Lake, and may therefore have an impact on plans for lake level stabilization. In this paper, a model based on energy and conservation of mass principles is applied to estimate the potential redistribution of sulfate within Devils Lake. The rate of redistribution may affect the lake’s ecosystem and the design of a possible water diversion to the Red River of the North for the purpose of stabilizing the water surface elevation. Included in the paper is the selection of model input parameters, model calibration with field measurements, and application of the model to five future scenarios.