The role of wetlands in water purification, natural management of surface water runoff, and as habitat preserve for numerous species is well established.
The Ramsar Convention on Wetlands (1971) defines wetlands as "areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six metres."
The US Clean Water Act (1973) recognized the importance of wetlands. Wetlands were interpreted to be "waters of the United States." Loss of wetlands result in increased water pollution and contribute to increasing chance of floods because wetlands are efficient absorbers of flood waters. Of the approximately 300,000 acres of U.S. wetlands lost every year, agricultural encorporation only accounts for about one-third. Wetlands are more often destroyed by development. For example, Florida has lost 46 percent and California has lost 91 percent of their respective coastal wetlands due to increased development.