Ashokan Dam, N Ulster co., SE N.Y., on Esopus Creek 1 mi/1.6 km N of Olivebridge, and 11.5 mi/18.5 km W of Kingston; 41°56'N 74°13'W. The 4,650-ft/1,417-m-long dam includes a 1,000 ft/305 m masonry sect. flanked at either end by earthen embankments with concrete-core walls. Spillway elev. 590 ft/180 m above sea level. Completed in 1912; impounds Ashokan Reservoir, a major component of N.Y. city water supply system. Capacity of 3 million acre-ft. Also known as the Olive Bridge or Olivebridge Dam.
