2.2.2 Geology and Soils

The depth to bedrock within the subwatershed varies from 300 to 400 feet.  Quaternary deposits – the surficial material overlaying the bedrock – are high relief New Ulm loamy till, with pockets of peat and muck distributed throughout the subwatershed.  The northeastern corner of the subwatershed is sandy till, part of a larger area of sandy till that surrounds St. Albans Bay.   Soils within the watershed are predominantly Natural Resources Conservation Service Hydrologic Soil Group B (loamy with moderate infiltration potential) (see Figure 3).   Group C (loamy clay with low infiltration potential) and D (clayey with very low infiltration potential) soils are found in low-lying areas and are generally hydric, or showing indications of inundation (see Figure 4).