2.2.2 Geology and Soils
The depth to bedrock within the subwatershed varies from 200 to 300 feet. Quaternary deposits – the surficial material overlaying the bedrock – are generally high relief New Ulm loamy till, with pockets of peat and muck and two large areas of clay deposits in the western subwatershed. Soils within the watershed are predominantly classified as Natural Resources Conservation Service Hydrologic Soil Group B (loamy soils with moderate infiltration potential) and D (clayey soils with very low infiltration potential) (see Figure 3). The Group D soils are found in low-lying areas and are generally hydric, or showing indications of inundation (see Figure 4) or are in areas of mucky soils. There are also scattered areas of Group C soils, finer-grained sandy clay loam soils with low infiltration potential.