Ball Mountain Dam is a dam in Jamaica, Windham County, Vermont, in the southeastern part of the state.The earthen and gravel gravity dam was constructed between 1957 and 1961 by the United States Army Corps of Engineers, with a height of 247 feet and a length of 915 feet at its crest. It impounds the West River of Vermont for flood control. The dam is owned and operated by the Army Corps of Engineers. The Corps identified safety and seepage problems with the dam in 2009, and has assigned it a Dam Safety Action Class rating of DSAC II, or "Urgent".The reservoir it creates, Ball Mountain Reservoir, has a normal water surface of 20 acres, a maximum capacity of 52,450 acre-feet, and a normal capacity of 240 acre-feet. Recreation includes fishing, camping at 111 campsites in nearby Winhall and Jamaica, and activities at the adjacent Jamaica State Park. The river between Ball Mountain Lake and downstream Townshend Lake is used for white water boating during releases from the Ball Mountain Dam, usually occurring during one weekend in April and one weekend in September.