Vermillion River Groundwater Plan+Study
documenting groundwater contributions and protecting groundwater resources
Located in a rapidly developing county, the Vermillion River is one of five high priority trout streams in the Twin Cities Metropolitan Area. As anticipated development within the watershed and along the river banks could significantly impact the Vermillion River, EOR evaluated the interaction of groundwater in the river, identified key recharge areas, and developed management policies for protecting the Vermillion River and cold water fisheries.
A total of 23 stream reaches were monitored as part of a long-term program which evaluated over 55 miles of river channel. The data were analyzed to determine the significance of groundwater interaction at each reach. EOR then created a suite of maps documenting the ground water influences on the Vermillion River that illustrated water contours, key recharge areas, and infiltration potential.
EOR’s groundwater monitoring included the recording of:
- surface water levels
- water levels at private residential wells
- water levels within the river using shallow hand driven piezometers
- water chemistry in the river, its tributaries, and nearby lakes
- river and river bed temperatures
- base-flow measurements
As the result of the study, EOR helped to develop an overlay district to guide groundwater policy and created a model ordinance to protect groundwater dependent resources and groundwater recharge quality and quantity. The model ordinance can also be used to help mitigate potential thermal impacts on groundwater.