Michigan Dept. of Environment, Great Lakes, and EnergyHydric soils indicate a current or former wetland condition, and for this layer, hydric inclusions (>15% hydric soils) were not added to the layer, while hydric complexes (<15% hydric soils) were included. This is a statewide layer that can be used as one resource in identifying current or former wetland areas. United States Department of Agriculture-National Resource Conservation Service (USDA-NRCS) Soil Survey Geographic database (SSURGO) Soils were used as the base dataset and hydric soil types were queried out on a county by county basis in a GIS environment. USDA-NRCS State Soil Scientists provided the hydric soil types in Excel table format by county, and Wetlands, Lakes, and Streams unit (WLSU) produced this layer from that official list. Field Name Descriptions CoverType This is the approximate historical landcover type. This data was pulled from the land 1800 Michigan Natural Features Inventory dataset. Its typcially used as part of the Landscape Level Wetland Functional Assesement. MapUnitSymbol Map unit symbol is an attribute that tracks the type of soil. This code can be used to look up information for a partical soil. Acres Size of the hydric soil polygon. AreaSymbol County code for location of the polygon. AreaName Name of the county in which the soil is found. MapUnitCode A symbol used to uniquely identify the soil map unit in the soil survey MapUnitName Correlated name of the mapunit (recommended name or field name for surveys in progress). Component Name assigned to a component based on its range of properties. Local Phase - Phase criterion to be used at a local level, in conjunction with "component name" to help identify a soil component. Representation The percentage of the component of the mapunit. Landforms A word or group of words used to name a feature on the earth's surface, expressed in the plural form. HydricRating A yes/no field that indicates whether or not a map unit component is classified as a "hydric soil". If rated as hydric, the specific criteria met are listed in the Component Hydric Criteria table. Because this data is a hydric layer all will be yes HydricCriteria Criterion code for the soil characteristic(s) and/or feature(s) that cause the map unit component to be classified as a "hydric soil." These codes are the paragraph numbers in the hydric soil criteria publication. NWIWater The approximated National Wetland Inventory water regime code assigned to this soil type. This was done as part of the Landscape Level Functional Assessment. NWICode Code generated from the landcover type and NWI water field. The approximated National Wetland Inventory Code approximated for this historic landcover. HGMCode Code for the Landscape Level Assessment. Combines each of the coded types. For example TEBAVR = Terrene Basin Vertical Flow Landform The type of geological feature in which the wetland resides. Slope (SL) Wetlands occurring on a slope of 5% or greater. Island (IS) A wetland completely surrounded by water. Fringe (FR) Wetland occurs in the shallow water zone of a permanent waterbody. *NWI water regime F, G, and H Floodplain (FP) Wetland occurs on an active alluvial plain along a river and some streams. *Modifiers FPba (Basin) and FPfl ( Flat) Basin (BA) Wetland occurs in a distinct depression. *NWI water regime C and E Flat (FL) Wetland occurs on a nearly level landform. *NWI water regime A and B Landscape_Position Landscape position values are determined by cross referencing NWI with hydrology and topography. NWI polygons that spatially intersect a stream/river in the National Hydrography Dataset (NHD) are classified as lotic. Lotic type wetlands can be further refined to indicate their adjacency to a stream or a river (lotic stream or lotic river). High resolution NHD data was used to differentiate rivers from streams in this analysis. A NHD classification completed by MDNR, Institute for Fisheries Research separated rivers by temperature gradient (cold, cool, warm) and size, based on average water flows (cubic feet per second or CFS). This dataset was used in the LLWFA analysis to mark this distinction. NWI Polygons that are determined to be within the basin of a lake are classified as lentic. Identifying the extent of a lake basin, and thus which wetlands fall within it, is done with the assistance of digital elevation models (DEM). NWI Polygons that don't intersect surface water features or aren't spatially located within a lake basin are classified as terrene Waterbody_Type Waterbody type classification is the simplest of the 4 LLWW descriptors. Ponds, lakes, and rivers are classified as such based explicitly on NWI Cowardin code. Lakes and ponds were separated at the 5-acre mark, all open-water polygons less than or equal to 5 acres were classified as ponds, while all open-water polygons larger than 5 acres were classified as lakes. The 5 acre cutoff was chosen to remain consistent with previously existing EGLE regulations. High resolution NHD data was used to differentiate rivers from streams in this analysis. A NHD classification completed by MDNR, Institute for Fisheries Research separated rivers by temperature gradient (cold, cool, warm) and size, based on average water flows (CFS) This dataset was used in the LLWFA analysis to mark this distinction. Waterflow_Path Water flow path, otherwise known as hydrodynamics, is classified by automated and manual interpretation of the intersection of NHD surface water features and NWI. Automated methods include intersecting NHD and NWI to capture throughflow wetlands (in-stream wetlands), both natural and artificial. A distinction is drawn in NHD between natural stream/river features and artificial canal/ditch features. Vegetated NWI wetlands that don't intersect any surface water body are classified as isolated. Detailed coding was developed in an effort to differentiate intermittent, artificial, and perennial connections between wetlands and other surface waterbodies. Any wetland classified as lentic (Landscape Position) is automatically assigned a water flow path of bidirectional, accounting for the tidal effects of lakes on adjacent wetlands Landform1 A secondary code used to determine type of floodplain and if a vegetated wetland is associated with a pond. Associated w/Pond (pd) Basin (ba) Flat (fl) Landscape1 Field used to display if a wetland falls within a Headwater area Headwater (hw) LLWFAComments Field used to make notes during the LLWFA coding process. HMValues All function Values combined to perform the count. FunCount Number of Functions each wetland could be performing. VegOrNotVeg<o:p></o:p> Is the wetland vegetated or open water (non veg). FloodWaterStorage Function field for Flood Water Storage H (2) = High M (1) = Moderate StreamflowMaintenance Function field for Streamflow Maintenance H (2) = High M (1) = Moderate NutrientTransformation Function field for Nutrient TransformationH (2) = High M (1) = Moderate SedimentRetention Function field for Sediment Retention H (2) = High M (1) = Moderate ShorelineStabailization Function field for Shoreline Stabilization H (2) = High M (1) = Moderate FishHabitat Function field for Fish Habitat. H (2) = High M (1) = Moderate StreamShading Function field for Stream Shading H (2) = High M (1) = Moderate WaterfowlWaterbirdHabitat Function field for Waterfowl and Water Bird Habitat. H (2) = High M (1) = Moderate ShorebirdHabitat Function field for Shorebird Habitat. H (2) = High M (1) = Moderate InteriorForestBirdHabitat Function field for Interior Forest Bird Habitat. H (2) = High M (1) = Moderate AmphibianHabitat Function field for Amphibian Habitat. H (2) = High M (1) = Moderate GroundWaterInfluence Function field for Ground Water InfluenceH (2) = High M (1) = Moderate CarbonSequestration Function field for Carbon Sequestration H (2) = High M (1) = Moderate PathogenRetention Function field for Pathogen Retention 1 = Wetlands that intersect 303d listed streams, 2 = Wetlands within a 500 ft buffer of 303d streams, 3 Streams that intersect wetlands that filter Pathogens, 4 wetlands within a 500 ft buffer that filter pathogens. For historical wetlands this would be showing best areas to do potential restoration. The hydric soils polygons are not updated, however attributes will be updated when Landcape Level Wetland Functional data is completed. For questions about this content reach out to Jeremy Jones at jonesj28@michigan.gov . or Chad Fizzell at fizzellc@michigan.gov You can also visit www.michigan.gov/wetlands or https://www.nrcs.usda.gov/conservation-basics/natural-resource-concerns/soil/hydric-soilsArcGIS DynamicMapLayerhttps://hub.arcgis.com/datasets/550aad975c21425e8a6ca124d32bcd3d_5engState of Michigan Open Data PortalPublicHydric Soils [Michigan]Web servicesMichiganLast Modified: 2025-09-24