Hydrogeologic Assessment of the Kenosha Dunes

Kristen Carlson, Daniel Kerstan, Benjamin Sieren and Advisor Dr. John Skalbeck, Department of Geosciences, University of Wisconsin – Parkside, 900 Wood Rd, Kenosha, WI 53144

The Kenosha Dunes complex within Chiwaukee Prairie State Natural Area in southeastern Wisconsin has recently experienced rapid shoreline erosion due to high water levels in Lake Michigan.  A hydrologic assessment was initiated in November 2019 to evaluate the impact of groundwater flow and bluff seepage on the erosion.  Monitoring wells PZ-1 and PZ-2 were installed between the erosion bluff and a wetland west of the dunes to measure groundwater elevations using dedicated pressure transducers.  Water samples from the wetland, the two wells, and the bluff seepage were collected for measuring field water quality parameters and for analysis of general chemistry at the UW–Parkside SC Johnson Integrated Science Laboratory.  Laboratory water chemistry results show a steady decline in sodium and chloride from the wetland toward the bluff suggesting the wetland serves as a source for groundwater recharge. Sieve analysis was conducted on cuttings from the well installation and from bluff samples to characterize grain size distribution and estimate the hydraulic conductivity.  Aquifer slug tests at the two wells were performed to calculate the hydraulic conductivity as well.  Agreement was found in the hydraulic conductivity values obtained from the two methods to yield an average value consistent with dune sands. An analytical model was created using Microsoft Excel to simulate groundwater elevations using local annual rainfall data for model recharge, the average hydraulic conductivity for aquifer transmissivity, and water level elevations from the wetland, the two wells, and the bluff seepage.  Model water elevations show good agreement with measured groundwater elevations and mimic the elevations consistent with the Dupuit–Forchheimer assumption for unconfined flow with a high hydraulic gradient adjacent to the bluff seepage.  The model can be used to simulate changes in hydraulic gradient and associate seepage flow with continued bluff erosion.

Additional Abstract Information

Presenters: Kristen Carlson, Ben Sieren , Daniel Kerstan

Institution: University of Wisconsin - Parkside

Type: Poster

Subject: Geography/Geology

Status: Approved

Time and Location

Session: Poster 7
Date/Time: Tue 3:30pm-4:30pm
Session Number: 5079