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Freshwater & Oceans

Tools for evaluating historic functional change

Wetland Prioritization Study Main Pag

 

Single-objective tools

 


 

The Nature Conservancy and Environmental Law Institute Duck-Pensaukee Watershed Approach Pilot Project (TNC-ELI DPWAP) Watershed Profile Tool: 1,2 To set watershed-wide conservation objectives, the team measured the historic change in magnitude and distribution of four wetland services using NWI+ LLWW (Landform, Landscape position, Waterbody type, and Water flow path) modifiers. Using LLWW classifications, the team identified the highest performing wetlands for each HUC-12 by applying a set of "functional correlations" between each LLWW classification and water quality protection, flood abatement, surface water supply, and carbon storage functions. For each of these functions, the team calculated historic change in functional performance for each HUC-12 watershed by comparing the current acreage of high functioning wetlands with the historic acreage of high functioning wetlands within each HUC-12. The planning team used this assessment to identify HUC-12s in which wetland restoration and preservation are most needed, opportunities for wetland restoration and protection that could benefit downstream areas, opportunities for wetland restoration and preservation of individual sites that would be most relevant in a watershed context, and opportunities for the conservation community to collaborate to restore and maintain wetland services.

 

Factor used in analysis

Data source(s)

NWI+ LLWW modifiers

NWI data supplemented with GIS analyses

Current wetlands

WWI wetland map data, converted to NWI format by USFWS

Historical wetlands

WWI wetland map data, converted to NWI format by USFWS; Hydric soils minus current wetlands and non-restorable land uses (e.g. developed areas)

 

Acronym definitions

 

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Wisconsin Department of Natural Resources (WDNR) Relative Need Tool:3 This tool measures the extent to which wetland restoration has the potential to improve wetland functions (e.g., flood storage, water quality, and habitat) within a subwatershed. The tool applies the equation below to score HUC-12 watersheds. Watersheds that have lost large amounts of wetland acreage but have few restored or remaining acres and have a large original wetland acreage relative to the total size of the HUC-12 are ranked highest. The tool does not evaluate specific functions, but rather assumes that wetland restoration will produce general functional improvement.

 

 

Factors used in analysis

Data source(s)

Lost wetland acres

PRWs

Restored wetland acres through federal, state, and non-profit partnerships.

WRTD

Remaining wetland acres

WWI; WRTD

Original (pre-settlement) wetland acres

WWI

Total wetland acres.

N/A

 

Acronym definitions

 

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Wetland Prioritization Study Main Page


 

1Miller, N., T. Bernthal, J. Wagner, M. Grimm, G. Casper, and J. Kline. 2012. The Duck-Pensaukee Watershed Approach: Mapping Wetland Services, Meeting Watershed Needs. The Nature Conservancy and Environmental Law Institute, Madison, Wisconsin.
2 Feedback received on 5/24/2012 from Nick Miller, Director of Science at The Nature Conservancy.
3 Hatch B, Bernthal T. 2008. Mapping Potentially Restorable Wetland in the Rock River Basin.