The reservoir's shoreline is approximately 160 mi (260 km), has submerged some 26 mi (42 km) of Tuolumne River bed, and has a surface area of about 13,000 acres (5,300 ha). The 2,030,000 acre·ft (2,500,000 dam³) stored here comes from a watershed of over 1,500 sq mi (3,900 km2), and is used by the Modesto Irrigation District (MID) and the Turlock Irrigation District (TID) for agricultural irrigation of several hundred square miles of productive Central Valley farm land. Some of the water is treated by the MID and used as drinking water in Modesto. The two irrigation districts and the BLM control the land 15 feet (4.6 m) above the high lake level, so there are no private boat docks on lakefront parcels. There are three public boat ramps.