In the United States, the National Estuary Program was created by the 1987 amendments (P.L. 100-4) to the Clean Water Act (P.L. 92-500, as amended) to provide grants to states where governors identify nationally significant estuaries that are threatened by pollution, land development, or overuse. Governors have identified a total of 28 estuaries, and the Environmental Protection Agency awarded grants to these states to develop comprehensive management plans to restore and protect the estuaries.