Groundwater Atlas of Houston County released; public workshop offered Feb. 25

The Minnesota Department of Natural Resources recently published “The Groundwater Atlas of Houston County.” The report covers groundwater flow, groundwater chemistry and the pollution sensitivity of aquifers. It also expands on the geologic atlas previously produced by the Minnesota Geological Survey by:

• Identifying viable drinking water sources
• Supporting sustainability
• Guiding decisions on well and septic system construction
• Informing wellhead protection efforts for public water supplies
• Highlighting regional recharge and groundwater movement
• Assessing aquifer pollution sensitivity and possible contaminant migration

In Houston County, pollution sensitivity information is especially important because much of the area’s landscape features karst. Karst is a distinctive type of terrain that forms when precipitation and groundwater dissolve underlying carbonate sedimentary rock. Sinkholes, fractures and voids in karst mean water can rapidly move from the surface to underlying aquifers. This increases the risk of common surface pollutants contaminating groundwater in shallow aquifers. Deep aquifers tend to be protected by bedrock layers, which slow the movement of groundwater, resulting in older, more pristine waters.

Public workshop

The DNR will share details on the Houston County atlas’ contents and its use during a public workshop from 1-4 p.m. Wednesday, Feb. 25. Join in-person in Conference Room EOC at the Houston County Criminal Justice Center in Caledonia or there is also an option to join online. In the event of unsafe travel conditions, the workshop will move to Tuesday, March 10, with the time and location remaining the same. If that happens, those registered will be notified by email.

To attend in person or online, please register through the County Groundwater Atlas events page (mndnr.gov/AtlasEvents) under the upcoming events tab, or email ([email protected]) for more information. The workshop is in partnership with Houston County and the MGS.

More information about the County Groundwater Atlas program is available on the DNR website (mndnr.gov/groundwatermapping).

Partial funding for this project was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources and by the Clean Water Fund, which receives 33% of the sales tax revenue from the Clean Water, Land and Legacy Amendment, approved by voters in November 2008.

The atlas is available:

• Online
• The report (files.dnr.state.mn.us/waters/groundwater_section/mapping/cga/c33_houston/hous-report.pdf) is available in PDF format.
• Maps of the water chemistry (files.dnr.state.mn.us/waters/groundwater_section/mapping/cga/c33_houston/hous-plate5.pdf) and hydrogeologic cross section (files.dnr.state.mn.us/waters/groundwater_section/mapping/cga/c33_houston/hous-plate6.pdf) plates are also available.
• Geographic information system (GIS) files (files.dnr.state.mn.us/waters/groundwater_section/mapping/cga/c33_houston/c33b_met.html), including the associated metadata and an ArcMap file, can be downloaded.

• In print
  • Copies of the complete atlas (report and plates) can be purchased online (dnr.oceangrafix.com/shop/minnesota/p/houston-c33-groundwater-atlas) from OceanGrafix.

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