Extent of available data.
This data layer is Soil Drainage Class from the Soil Survey Geographic Database (SSURGO). It was developed by the Natural Resources Conservation Service. SSURGO contains information on soils collected by the National Cooperative Soil Survey over the course of a century. Soil Drainage Class indicates how quickly water drains from an area and the frequency and duration of wet periods for the soil. There are seven drainage classes ranging from excessively drained to very poorly drained. The drainage characteristics of soil dictate the types of vegetation that can grow and the activities that can take place. Poorly drained soils often indicate the presence of wetlands.