The Genesee River Basin covers 2,479 square miles, mostly in western New York, with a small portion, 96 square miles in northwestern Pennsylvania. The river rises in the Allegheny highlands in Potter County, Pennsylvania, at an elevation of about 2,500 feet, flows approximately 157 river miles in a generally northward direction to its mouth at Rochester Harbor on Lake Ontario, at an elevation of about 247 feet. The topography of the southern portion, the Upper Basin, upstream of Mount Morris Dam, is steep and rugged, while the northern portion, the Lower Basin, is gently rolling. The two major divisions of the basin also closely parallel the two land resource areas which comprise the basin: the Allegheny Plateau and the Ontario Lake Plains Service Area, a region of about 750 square miles north and west of the Basin lying between Rochester and Lockport, New York. The principal needs are for flood protection, water quality control, recreation, fish and wildlife enhancement, irrigation, and agricultural land and water management. The most practicable means to provide for these and other needs of the basin is through a comprehensive plan of structural and non-structural measures.