A hydric soil is a soil that is saturated, flooded, or ponded long enough during the growing season to develop anaerobic conditions. In Michigan, the state's legal definition of wetland makes no mention of soils. However, the administrative rules do direct the use of soils as an indicator of the presence of water under abnormal circumstances or when signs of hydrology are not conclusive. Many different types and textures of soils are found in wetlands including mucks, peat, loams, clays, and sands. Mucks and peat are obvious wetland soils, but even loam, clay, and sandy soils can be wetland soils if they are frequently saturated or inundated.
Soil scientists can interpret soils in a way that describes the history of water exposure.
Soil surveys are available for most counties in Michigan and those unavailable will be completed soon. Modern Soil Surveys have been produced by detailed field work translated into coded areas on aerial photographs. Each major soil series is identified throughout the county and described in text. Reviewing descriptions for soils on a parcel can provide a great deal of information about the likely presence or absence of wetland conditions. Other useful information is seasonal depth to groundwater, typical vertical profiles, suitability of the soil for various purposes, etc.