Engineering Commons^™

Development And Assessment Of A Groundwater Sustainability Index In Climatically Diverse Groundwater Irrigated Regions In Nebraska, Maria A. Mulet Jalil

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The aim of this research was to evaluate the impact of regional change in ET on groundwater level changes and the assessment and development of a groundwater sustainability index for climatically diverse regions across Nebraska during 2000-2014. Irrigation in the selected regions is predominantly supplied by groundwater. The hypothesis is that groundwater use can become sustainable if the regional evapotranspiration (ET) is managed so that it equals the ET of vegetation that is native to the region. Site locations were Box Butte, Chase, Dundy, Holt LNNRD and York Counties and 3 ecosystems were evaluated: native vegetation, dryland and irrigated cropping …

Seepage And Stability Of A Dam In An Artesian Setting, Sean A. Parks

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Willow Creek Dam is located in a unique region on the boundary of a confined aquifer, where artesian conditions exist. Recently, groundwater levels have exceeded the elevation of the downstream berm well above anticipated piezometric elevations. It was presumed from limited evidence that these high piezometric levels resulted from pressure in the aquifer rather than from seepage out of the reservoir. The purpose of this investigation was to determine the relative contributions of the reservoir and the regional groundwater to observed piezometric levels and how these levels affect seepage exit gradients and slope stability of the dam.

Comparing the head …