Date of Award:


Document Type:


Degree Name:

Master of Science (MS)


Civil and Environmental Engineering

Committee Chair(s)

Brian Mark Crookston


Brian Mark Crookston


Som Dutta


Bethany T. Neilson


The Great Salt Lake in Utah, USA, is a terminal, saline lake and is divided into two primary sections (northern and southern) by an east-to-west railroad causeway. Shortly after completion of the earth-fill causeway in the late 1950s, the two sections became dramatically different with differences in water surface elevation and water density. These differences cause the formation of a unique flow behavior commonly referred to as a density-driven exchange flow or bi-directional flow; a behavior observed in other lake and ocean settings where two fluids of differing densities interact. Measuring these exchange flows is a priority for lake managers who face the challenge of preserving the numerous societal and environmental benefits the lake provides. Due to rising environmental and economic concerns associated with varied lake salinity and water surface elevation, a new 50 m-wide breach was added to the railroad causeway to enhance salt and water exchange between the northern and southern sections. To support management efforts, exchange flows through the new breach were investigated using a computer modeling technique called computational fluid dynamics (CFD) supplemented by a field campaign. The results of this investigation indicate exchange flows through the breach are sensitive to fluctuations in density and water surface elevation differences in addition to the breach geometry and bathymetry. The model accurately predicted flow velocities and volumes and was used to forecast discharge through the breach as a function of the water surface elevation and density gradients under future lake conditions.