16 U.S.C. § 1003a

(a) Easements The Secretary may provide cost share assistance to project sponsors to enable such sponsors to acquire perpetual wetland or floodplain conservation easements to perpetuate, restore and enhance the natural capability of wetlands and floodplains to retain excessive floodwaters, improve water quality and quantity, and provide habitat for fish and wildlife. (b) Amount The Secretary shall require that project sponsors of watershed projects provide up to 50 percent of the cost of acquiring easements under subsection (a).