The Niagara project, located about 4 1/2 miles downstream from the Falls, consists of two main facilities: the Robert Moses Niagara Power Plant, with 13 turbines, and the Lewiston Pump-Generating Plant, with 12 pump-turbines. In between the two plants is a forebay capable of holding about 740 million gallons of water; behind the Lewiston plant, a 1,900-acre, 22 billion gallon reservoir holds additional supplies of this liquid fuel.

Water is diverted from the Niagara River—up to 375,000 gallons a second—and conveyed through conduits under the City of Niagara Falls to Lewiston. From there, water flowing through the Robert Moses plant spins turbines that power generators, converting this mechanical energy into electrical energy.

At night, when electricity demand is low, the Lewiston units operate as pumps, transporting water from the forebay up to the plant's reservoir.

During the daytime, when electricity use peaks, the Lewiston pumps are reversed and become generators, similar to those at the Moses plant. In this way, the water can be used to produce electricity twice, increasing production and efficiency.

To balance the need for power with a desire to preserve the beauty of Niagara Falls, the United States and Canada signed a treaty in 1950 that regulates the amount of water diverted for hydroelectricity production. On average, more than 200,000 cubic feet per second (cfs), or 1.5 million gallons of water a second, flow from Lake Erie into the Niagara River. The 1950 pact requires that at least 100,000 cfs of water spill over the Falls during the daylight hours in the tourist season, April through October. This flow may be cut in half at night during this period and at all times the rest of the year.

*** Update on progress of facility upgrade:

Open-loop Pumped Hydro Storage