ENHANCING THE NATIONAL WETLAND INVENTORY FOR LANDSCAPE-LEVEL WETLAND FUNCTIONAL ASSESSMENT
EXAMPLE OF NWI
COWARDIN WETLAND CLASSIFICATION SYSTEM 5 DESCRIPTORS SYSTEM SUBSYSTEM CLASS WATER REGIME SPECIAL MODIFIER
FWS Classification Shortcomings Shortcomings No landscape position No landform No water flow direction General pond classification Features important for assessing many functions are lacking Most of these features can be interpreted from the maps
Some Questions How many wetlands are there? What is the size range of wetlands? What is the average size of a given wetland type? How many wetlands are in various size classes? How much and how many occur along rivers? along streams? in lake basins? are isolated? are sources of streams? have inflow but no outflow? are connected to other wetlands? What types of ponds are there and what is their extent?
Add New Descriptors to the NWI Database LLWW Descriptors Landscape Position - relationship between a wetland and an adjacent waterbody or not Landform - shape or physical form Water Flow Path - directional flow of water Waterbody Type more specificity
Data for Watershed-based Wetland Primary Source Data NWI Digital Data USGS Digital Hydro Data (1:24K) Other Sources USDA Digital Soil Survey Data State Wetland Digital Data More Detailed Hydro Data Aerial Photos Assessments
Limitations of Landscape-level Assessment First approximation Source data limitations All wetlands not shown Possible upland inclusions All streams not shown Age of data LLWW wetland classifications based largely on map interpretation (field review variable) Correlations between functions and characteristics = work in progress (report available for Northeast US; most applicable nationwide, need some modification for habitat functions)
STATUS & TRENDS Two-fold approach QUANTITY QUALITY VS. Quantifiable acreage amounts Status of each wetland over time Changes in wetland type Tracking of gains/losses Reason for wetland loss Landscape-level functional assessments Enhancement of NWI data Functional Correlations
Non-Regulatory Programs Level 1: Landscape Level Assessment/ NWI Enhancement and Functional Assessment 2 WATERSHEDS --- 2 APPROACHES Approach 1 -- Paw Paw River Watershed - Work done by LWMD staff in-house - Approximately 7500 wetlands to be classified Approach 2 -- River Raisin Watershed - Work done by watershed council staff with guidance from LWMD staff - Approximately 11,000 wetlands to be classified
Non-Regulatory Programs Level 1: Landscape Level Assessment/ NWI Enhancement and Functional Assessment Determining LLWW Descriptors 1. Build a Geodatabase that encompasses spatial watershed data: Hydrology (NHD, State data), Digital Imagery, Topography, Soils, Geology 2. Based on NWI Code (Water Regime) and hydrological characteristics of a wetland, classify descriptors 3. Concatenate HGM Code for each wetland based on: Landform, Landscape Position, and Water Flow Path = Vegetated Wetlands Waterbody Type and Water Flow Path = Open Waterbodies 4. Connect HGM Code with Functional Correlations prepared by USFWS
Non-Regulatory Programs Landform Landscape Position Water Flow Path Waterbody Type Level 1: Landscape Level Assessment/ NWI Enhancement and Functional Assessment Slope Island Terrene Lentic Isolated Inflow Lake River EXAMPLE 1 -NWI Code = PF01C -H20 Regime = C or Seasonally Flooded LANDFORM = BASIN Fringe Floodplain Basin Flat Lotic River Lotic Stream Outflow Throughflow Bidirectional -Nontidal Pond Vegetated Wetland LANDSCAPE POSITION = TERRENE WATER FLOW PATH = ISOLATED WATERBODY TYPE = VEGETATED WETLAND HGM CODE = TEBAIS Example 2 CORRELATED FUNCTIONS = Surface Water Retention (High), Nutrient Transformation (High) Example 1
Non-Regulatory Programs Landform Landscape Position Water Flow Path Waterbody Type Level 1: Landscape Level Assessment/ NWI Enhancement and Functional Assessment Slope Island Terrene Lentic Isolated Inflow Lake River EXAMPLE 2 -NWI Code = PF02B -H20 Regime = B or Saturated LANDFORM = FLAT LANDSCAPE POSITION = TERRENE Fringe Floodplain Basin Flat Lotic River Lotic Stream Outflow Throughflow Bidirectional -Nontidal Pond Vegetated Wetland WATER FLOW PATH = OUTFLOW HEADWATER WATERBODY TYPE = VEGETATED WETLAND HGM CODE = TEFLOUhw CORRELATED FUNCTIONS = Surface Water Detention (Moderate), Streamflow Maintenance (High) Example 1 Example 2
Surface Water Detention (flooding mitigation) High Potential Fringe Wetlands Basin Wetlands Floodplain Wetlands Throughflow Ponds (in-stream) Moderate Potential Flats Interfluves Other Ponds (except sewage treatment ponds and similar waterbodies)
Streamflow Maintenance High Potential Nonditched Headwater Wetlands (hw) 1 st order perennial streams and above 2 nd order perennial streams in mountainous/hilly regions Moderate Potential Ditched Headwater Wetlands (hw + NWI d wetland) Lotic Floodplain Wetlands Throughflow Ponds and Lakes* (PUB on NWI) and associated wetlands Outflow Ponds and Lakes* (PUB on NWI) Terrene Outflow Wetlands (adjacent to streams) *Probably need to change NWI code
Nutrient Transformation High Potential Seasonally Flooded or wetter Vegetated NWI Wetlands and Tidal Equivalents (N, P, R, T, L) Permanently Saturated Vegetated Wetlands (bogs) Moderate Potential Seasonally Saturated and Temporarily Flooded Vegetated Wetlands and Tidal Equivalent (S)
Retention of Sediments and Other Particulates High Potential Vegetated Wetlands (wetter water regimes) Basin, Fringe (exc. Rocky Shore), Island, Floodplain Wetlands Lotic Basin Throughflow and Bidirectional Ponds and Lakes (PUB on NWI) and associated vegetated wetlands Terrene Throughflow Basin Wetlands Moderate Potential Nonvegetated Wetlands Vegetated Flat Wetlands (excluding bogs) Some others
Shoreline Stabilization High Potential Vegetated (except island types) along waterbodies Estuarine, Lotic, and Lentic Marine/Estuarine Rocky Shore (except islands) Moderate Potential Terrene Vegetated Wetlands along Ponds
Provision of Fish and Shellfish High Potential Habitat Estuarine Emergent, Unconsolidated Shore, Intertidal Reef, Aquatic Bed, and Rocky Shore (plus similar Marine, Riverinetidal, and Pal-tidal Wetlands excluding S water regime and EM5 = Phrag) (Add certain mangroves E2SS3 and E2FO3 Southeast) Lacustrine Semipermanently Flooded, Littoral Aquatic Bed, Unconsolidated Bottom/Vegetated Wetland, Permanently Flooded and Vegetated (add L2UBH) Palustrine Semi-permanent (contiguous with permanent waterbody) and associated ponds, Palustrine Unconsolidated Bottom/Vegetated
Fish and Shellfish (cont d) Moderate Potential E2FO and E2SS mixed with EM Palustrine Tidal FO and SS mixed with EM and having R or T water regime Lentic PEMIE Wetlands including mixes with FO and SS (Northeast) Other Ponds with Fringe Wetlands Excludes industrial, stormwater, and similar ponds in highly disturbed landscapes and ponds with K or F water regimes
Provision of Waterfowl and Waterbird Habitat High Potential Similar to Fish Habitat Includes PEM1E along streams (probably marshes) Beaver Ponds and associated wetlands Ponds associated with P F wetlands Wood Duck Potential Lotic Wetlands that are FO and SS with C and wetter water regimes Some others
Waterfowl and Waterbird Moderate Potential Habitat Seasonally flooded and wetter Phragmites wetlands E2EM5 and contiguous with waterbody PFO/EM1R and other tidal wetlands where EM is subordinate Lacustrine Littoral Unconsolidated Bottom Other Ponds (excluding industrial, commercial, stormwater, sewage treatment and similar ponds) PEM wetllands (including mixes with SS) that are Seasonally Flooded and wetter and associated with a waterbody
Provision of Other Wildlife High Potential Habitat Large vegetated wetlands > 20 acres (excluding open water, nonvegetated wetlands, and pine plantations) Small diverse wetlands (10-20 acres with 2 or more covertypes, excluding Phrag and open water types) Areas with large number of small isolated wetlands (including small ponds that may be vernal pools) Moderate Potential Other vegetated wetlands
Conservation of Biodiversity Unique types for the watershed Wetland types recognized as important or scarce regionally Riverine tidal emergent wetlands Palustrine tidal emergent wetlands Palustrine tidal scrub-shrub wetlands Urban wetlands Calcareous fens Lotic Fringe wetlands Headwater seep wetlands? Forested wetlands in forest complexes >7410 acres Shrub bogs Lentic fringe wetlands (EM/AB and AB/EM)
Non-Regulatory Programs Level 1: Landscape Level Assessment/ NWI Enhancement and Functional Assessment PRACTICAL USES OF ENHANCED NWI: Uses Depend on the Watershed: Urban Environment---Surface Water Retention Agricultural Environment---Nutrient Transformation Across the Board: Identifying Headwaters Targeting Areas for further assessment/ protection Mitigation Banks Wetland restoration opportunities WHAT IT WILL NOT DO: Guide regulatory decisions
Pre-settlement vs. 1998 Paw Paw River Watershed Pre-settlement 82,503 acres 5,824 wetlands (could change) Average Size 14.17 acres 1998 44,270 acres 7,581 wetlands Average Size -- 5.84 acres