Directs the Secretary of the Army to convey the remaining water supply storage allocation in Rathbun Lake, Iowa, to the Rathbun Regional Water Association in exchange for such Association: (1) constructing, operating, and maintaining a regional lighthouse visitors center complex on Federal lands at Rathbun Lake; (2) paying all operation and maintenance costs allocated to the water supply storage space; and (3) using any complex revenues in excess of amounts required to operate and maintain or improve the complex to improve the quality of the environment in the Rathbun Lake watershed.