Jackson Graham
Department of Geosciences, UW-Milwaukee, jpgraham@uwm.edu
A local-scale groundwater-flow model of the Cedar Creek Watershed and Cedarburg Bog area was constructed to determine the effects of future changes in temperature and precipitation on water resources. The Cedar Creek Watershed is a 330 km2 subbasin of the Milwaukee River Watershed located about 30 km north of Milwaukee. The importance of this watershed lies in its location at the sub-continental divide separating the Mississippi River Basin from the Great Lakes Basin. The coupled steadystate and transient flow models incorporate interaction between surface water features and groundwater-surface water interactions.
The 4-layer model simulates the influence of recharge on the local flow regime using recharge estimates using the Soil-WaterBalance Code (SWB) from the USGS. The model contains two geologic units, surficial glacial deposits and the Silurian dolomitic bedrock. The hydraulic conductivities and storage parameters were calibrated using the parameter estimation software, PEST, based on 192 head targets of the static groundwater level reported by well drillers over the past four decades. Calibrated hydraulic conductivities from a 15-year average climate result in model simulations with residual mean of 0.14 m, standard deviation of 2.68 m and RMS error of 2.69 m. Results from the simulations show that the water table remains relatively stable over years of very low recharge and very high recharge, in addition to an approximate three month lag of lowering groundwater table after a summer of significant low recharge. M.S. Thesis research, Dr. Weon Shik Han, Major Advisor