Delaware's Wetlands Status and Trends reports are based on the results of wetland trends analyses performed by the U.S. Fish and Wildlife Service's National Wetlands Inventory (NWI) Program for Delaware’s Department of Natural Resources and Environmental Control. The two studies involved a comparison of aerial photographs from the early 1980's vs. the early 1990's and then again for 1992 vs. 2007. In both studies, wetland trends were identified as going to (loss) or coming from (gain) a specific land use or land cover type.

Wetlands provide many services on the landscape including cleaning our water, capturing and holding water to reduce flooding and contribute to groundwater supplies, protecting the coast from storms, and providing habitat for fish and wildlife species. As they are lost or degraded, these services are diminished and our quality of life can be impacted including costly damage to property.

Based on the 2007 study as much as 25 percent of Delaware was covered by wetlands, with over 320,000 acres inventoried. Tidal wetlands represented about 23 percent of the State's wetlands while non-tidal wetlands comprised the remainder.

Delaware may have lost as much as 54 percent of its wetlands since the 1780’s. The most recent study indicates that Delaware lost almost 50 percent more wetland acreage during the span of 1992 to 2007 vs. 1981-2 to 1992.