The HHPLS identified the infiltration potential of the most of the upland areas within the subwatershed as medium to low with some areas of variability where the soils are organic in nature (see Figure 16). A large area of high infiltration potential in the eastern subwatershed is associated with an area of sandy till and glacial outwash deposits. There are numerous areas of high aquifer sensitivity in the subwatershed (see Figure 17).
The Wellhead Protection Area for a Minnetrista municipal well is located in the subwatershed, as well as parts of wellhead protection areas for Minnetrista, Minnetonka and Plymouth wells. In addition, Drinking Water Sensitivity Management Areas (DWSMA) for those areas noted above have been defined as well. The Minnesota Department of Health has designated these areas to be of low to moderate risk and vulnerability to contamination of the drinking water supply. Figure 18 shows the DWSMAs and associated Wellhead Protection Areas.
The County Well Index has records of approximately 990 wells in the subwatershed, mostly shallow (less than 300 feet deep) domestic water supply wells.