The Role of Groundwater in the Flooding History of Clear Lake, Wisconsin

Wisconsin_2012_1What: The 2012 Clear Lake project will investigate the causes and impacts of the persistence and magnitude of groundwater flooding at Clear Lake and other kettle lakes in the glaciated terrain of the upper midwestern United States.

When: July 8-August 4

Where: Project members will spend three weeks in the field at Clear Lake. The final week of the program will be spent on the campus of Beloit College, so that we can utilize the laboratory and computer facilities at Beloit College and Northern Illinois University.

Who: Six students, Sue Swanson (Beloit College), Justin Dodd (Northern Illinois University), and Madeline Gotkowitz (Wisconsin Geological and Natural History Survey)

Project Overview and Goals

Record precipitation in 2007 and early 2008 contributed to widespread flooding across southern Wisconsin in June 2008. Yet months after surface waters drained, some areas outside of delineated floodplains remained inundated with water. This groundwater flooding resulted as water levels in the shallow sand and gravel aquifer rose, and then fell very slowly. Residents of Clear Lake, Wisconsin report about 7 feet of lake level rise over the last several years, peaking in summer 2009. In addition to flooded homes and cabins, local residents must contend with flooded septic systems, a potential source of pathogens and other contaminants to Clear Lake and to the many shallow wells that supply nearby residences. These economic losses and detrimental health impacts attest to the need for an improved understanding of the hydrogeologic and climatic conditions that lead to groundwater flooding. This project seeks to refine a hydrogeologic conceptual model for Clear Lake, a kettle lake in the glaciated portion of Wisconsin, and the significant components of the lake’s water budget. We will also explore long-term climate proxies to better understand the context within which the current groundwater flooding event is occurring and evaluate immediate and detrimental water quality impacts of the flooding.

Potential Student Projects

Listed below are student projects within the overall project goal of evaluating causes and impacts of the persistence and magnitude of groundwater flooding at Clear Lake and other kettle lakes in the glaciated terrain of the upper midwestern United States.

  • Hydrogeologic Assessments. Development of a conceptual model for groundwater flow in the vicinity of Clear Lake: One student will develop a hydrostratigraphic framework for groundwater flow by interpreting well construction reports for private wells near Clear Lake. Monitoring wells will also be drilled and installed as part of the project. The student will be responsible for logging and describing sediments during drilling and conducting single well response tests (slug tests) after well installation to estimate hydraulic properties of the geologic materials.Assessment of lake seepage conditions: One student will measure and map the distribution of seepage into and/or out of the lake using mini-piezometers and seepage meters. The student will also develop a complementary bathymetric map of the lake so that lake volume and storage can be evaluated at differing lake levels.
  • Evaluating Long-Term Flooding and Climate Conditions. Geochemical analyses of lake core sediments: Two students will examine variations in the stable isotope composition of the lake sediments. One student will isolate diatom frustules from the lake cores and measure the oxygen isotope values of the diatom silica. The second project will focus on the carbon and oxygen isotope composition of authigenic carbonate minerals and organic material from the lake sediments.Microfossil description: Diatom species are sensitive to changes in lake hydrology; therefore, another student will focus on species variations in the diatom assemblage to reconstruct long term changes in lake conditions.
  • Impacts of Groundwater Flooding. Evaluating the environmental impacts of flooded septic systems on lake water quality: This project will involve sampling lake and shallow groundwater and analyzing samples for constituents that are typically elevated in domestic wastewater, including major ions, conductivity, and nitrate-nitrogen isotopes.

Working Conditions

The group will spend three weeks in the field and one week on the Beloit College and NIU campuses. A cabin on Clear Lake will serve as our base in the field. We will drive or canoe to field sites on a daily basis. Fieldwork will involve hiking, walking through and working in wetlands, wading in the lake, and working from canoes and rafts. Students should be comfortable in the water and able to swim. Hiking boots and waterproof knee boots are required, and waterproof sandals are highly recommended. Life jackets and waders will be provided. The cabin that we will stay in has electricity and plumbing. It also has a fully-equipped kitchen, so the group will cook together. While on the Beloit College campus, students will be housed in dorms.

Required Gear

Wisconsin_2012_2

Beyond the obvious clothes/toiletries/prescription medications, you’ll want:

  • waterproof knee boots
  • hiking boots
  • swimwear
  • rain gear
  • sleeping bag
  • day pack
  • sunglasses
  • sunscreen
  • bug repellent

Recommended Courses/Prerequisites

Students should have completed the junior year and have had at least one course in hydrogeology, geomorphology, geochemistry, or sedimentology. Courses in geographic information systems, freshwater ecology, or paleontology (for the diatoms project) will also be helpful.

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