As used in this article, unless the context requires a different meaning: “Agency of this Commonwealth” includes the government of this Commonwealth and any subdivision, agency, or instrumentality, corporate or otherwise, of the government of this Commonwealth. “Board” means the Board of Conservation and Recreation. “Develop” or “development” means the replenishment and restoration of existing public beaches. “Erosion” means the process of destruction by the action of wind, water, or ice of the land bordering the tidal waters of the Commonwealth. “Government” or “governmental” includes the government of this Commonwealth, the government of the United States, and any subdivision, agency, or instrumentality, corporate or otherwise, of either of them. “Locality” means a county, city or town. “Program” means the provisions of the Public Beach Conservation and Development Act. “Public beach” means a sandy beach located on a tidal shoreline suitable for bathing in a county, city or town and open to indefinite public use. “Reach” means a shoreline segment wherein there is mutual interaction of the forces of erosion, sediment transport and accretion. “United States” or “agencies of the United States” includes the United States of America, the United States Department of Agriculture, and any other agency or instrumentality, corporate or otherwise, of the United States of America.