"Evapotranspiration, Surface Water, and Ground Water Influences at a Nebraska Sand Hills Wetland Mitigation Site" Wyatt Webster; Advisor Kyle Hoagland The development of a water budget for a wetland mitigation site to address performance standards outlined by the United States Army Corps of Engineers (USACoE) is essential in determining site viability in maintaining wetland functions replaced due to Section 404 procedures of The Clean Water Act. The history of wetland mitigation sites in the Sand Hills region of north-central Nebraska is poorly-defined and often non-existent. Although several wetland complexes in interdunal valleys are well studied (e.g., Burba et al. 1999; Gosselin et al. 2006; Harvey et al. 2007), studies focusing on the enhancement or restoration of wetland mitigation sites in the Sand Hills are lacking, yet essential in preserving regional aquatic resources. A year-long field study was conducted on a semi-arid wetland mitigation site in the Sand Hills. The principal objective of this study was to develop a more complete water budget necessary to meet USACoE regulatory performance standard specifications. Utilizing on-site meteorological instrumentation and the Bowen-ratio energy budget approach, surface energy balance ET measurements were correlated with the influence of the highly variable water table depth and on-site surface water retention and flow. Groundwater and surface water fluxes were assessed via observation wells and a flume. A secondary objective was to make use of these estimates to meet credit certification requirements, to allow its use as a wetland mitigation bank site for future Nebraska Department of Roads (NDOR) projects. Thus, this study will benefit NDOR in providing a monitoring protocol, as well as the potential acquisition and restoration of additional wetland mitigation sites in the Nebraska Sand Hills.