Summary of Hydrogeologic Conditions by County for the State of Michigan (USGS, 2007)

Purpose of the Report

• To provide a county-by-county overview of Michigan’s hydrogeologic conditions.
• Prepared as part of Michigan’s Groundwater Inventory and Mapping program (GWIM).
• Serves as a reference for state agencies, water managers, and the public.

Content and Structure

• Each county section includes:
  • Watersheds present in the county.
  • Glacial geology (extent, thickness, and nature of deposits).
  • Bedrock geology (rock units, aquifer potential, and confining units).
  • Well data from the Wellogic database (number of wells in glacial vs. bedrock aquifers).
  • Aquifer properties where available, such as transmissivity and permeability.

Major Points

• The report compiles data from multiple sources, including well records, geologic maps, and previous USGS studies.
• Hydrogeologic conditions vary greatly across the state depending on glacial deposits and underlying bedrock.
• Some counties have extensive glacial deposits that form productive aquifers; others rely more heavily on bedrock aquifers.
• The report provides tabular and mapped data to show aquifer distribution and well use by county.
• It includes notes on water quality issues when available (e.g., hardness, iron, salinity in deeper units).

To view this report: –> Summary of Hydrogeologic Conditions by County for the State of Michigan (USGS, 2007)