Magic Dam is an earthen embankment dam across the Big Wood River in southwestern Blaine County, Idaho, in the United States, about 40miles north of Twin Falls. The dam was completed in 1910 by Magic Reservoir Hydroelectric, Inc. for irrigation, flood control and hydroelectric generation, and stores up to 195000acre feet of water in Magic Reservoir, which lies in both Blaine County and adjacent southeastern Camas County.[1] Water from the reservoir is used to irrigate 89000acres around and between Shoshone and Richfield.[2] Magic Dam also supports a power station with three turbines totaling a capacity of 9,000 kW.[3]
The dam's main embankment is 128feet high and 3100feet long.[1] Two auxiliary dikes keep the reservoir from overflowing during high elevations, while a concrete emergency spillway located west of the dam helps to pass floodwaters. At full water levels, Magic Reservoir covers up to 3740acres, extending 6miles up the Big Wood River and 2.5miles up a tributary, Camas Creek. The dam and reservoir control runoff from a catchment area of 1600mi2.[1]