The purpose of designating hydric soils as critical areas is to assure the protection of environmentally fragile soils classified as being hydric by the United States Department of Agriculture, Natural Resources Conservation Service. By definition, hydric soils are either saturated at or near the soil surface with water that is virtually lacking free oxygen for significant periods during the growing season or flooded frequently for long periods during the growing season.

As a result, hydric soils may develop anaerobic conditions that favor the growth of hydrophytic vegetation, and therefore, may be associated with a wetland. In Montgomery Township, the identified hydric soils consist of, but are not necessarily limited to, Bowmansville, Cokesbury, Croton, Elkton, Fluvaquents, Lamington, Parsippany, Parsippany Variant, or Watchung soils.