"The Taum Sauk reservoir is a pumped-storage hydro plant located in Annapolis Missouri, about two hours south of St. Louis. The reservoir generates electricity by pumping water from the lower reservoir by two reversible pump-turbine generators through 7000 feet of tunnel, 25 feet in diameter, to the upper reservoir. The water then is drained back into the lower reservoir, generating electricity. The upper reservoir covers an area of 55 acres, is 90 feet deep and holds 1.5 billion gallons of water."
Dams, In The News, Power - Hydro