Two common methods are currently used to delineate wetlands.� The US Army Corps of Engineers' (ACOE) wetland delineation method utilizes field hydrology, soil, and vegetation indicators.� The US Fish and Wildlife Service (USFWS) relies on remote sensing technology to create wetland maps in the National Wetland Inventory program (NWI).� �The New York State Freshwater Wetlands Map was created using the NWI method.� This study compared the interpretations of the two wetland delineation methods.� Twenty wetlands listed on the New York State Freshwater Wetlands Map within the Ausable River Watershed in Essex County, NY were selected for this study.� Sampling locations within and beyond each wetland boundary as listed on the wetland map were positioned as a grid across the landscape.� Of the 303 study sites, 236 (78%) were identified as wetlands on the wetlands map; 67 (22%)were bordering the wetlands on the wetland map.� Wetland hydrology, soil and vegetation indicators were observed and recorded following the methods described on the ACOE wetland delineation manual in summers 2008 and 2009.� �

Results/Conclusions �

Of the 236 sites considered wetlands by the NWI criteria, 213 (98%) were also considered wetlands by the ACOE criteria. Of the 67 sites not considered wetlands by the NWI criteria, 23 (34%) were also not considered wetlands by the ACOE criteria. There was a discrepancy between the two methods in 67 (22%) of the total 303 sites. This discrepancy in the 23 sites considered wetlands by the NWI criteria but not by the ACOE criteria was due to a lack of hydrology indicators in 20 of the sites (87%). In our study area discrepancies between delineations of wetlands using the two methods were most often caused by the site not meeting the hydrology requirement of the ACOE method.