Under Chapter 532, Laws of 1922, the Superintendent of Public Works was authorized to develop water power at the new Barge Canal dams at Crescent and Vischer Ferry, and all contract work at both plants was completed in 1925. Each plant was equipped with two 2,800 kW, 0.8 power factor, 3 phase, 60 cycle, 2,300 volt, 90 rpm vertical generators, each directly connected to and powered by a 4,000 horsepower reaction-type Francis turbine, with the generators furnished by General Electric of Schenectady, New York. Both power plants were officially conveyed to the Power Authority of the State of New York on March 13, 1984, by the New York Department of Transportation. In 1989, the Power Authority added two turbine-generator units to each plant, more than doubling capacity, and the additional electricity replaced about 3,200,000 gallons of oil annually. The vertical turbines were purchased from Vroth Hydro of York, Pennsylvania, and both the Crescent and Vischer Ferry dams and powerhouses were rehabilitated at that time. The Mohawk Towpath Byway follows the historic route of the Erie Canal between Waterford, Cohoes, and Schenectady. At Lock 7 and the dam, the Erie Canal and towpath were cut from shale bedrock on this side of the river, creating the deepest rock cut on the original Erie Canal at 32 1/2 feet, deeper than the Niagara Escarpment cut west of Lockport at 31 1/3 feet. West of here, the Mohawk River narrows through the Rexford gorge, where the Erie Canal shared the riverbed, and the towpath was built above the river with a substantial stone-lined slope wall. The old Erie Canal was replaced when the river was made navigable. During construction of the current Erie Canal between 1907 and 1914, a fixed dam was built here to raise the water level and create a navigable channel for barge traffic in the Mohawk River. Lock 7 was constructed on the south side of the dam in Niskayuna. The dam is 36 feet high, nearly 2,000 feet long, Z-shaped, and runs from the power plant to Goat Island and then to Lock 7, raising the Mohawk's water level about 26 feet. Lock 7, on the south side of the Vischer Ferry Dam, has a lift of 28 feet and is a direct current lock that gets its power from the Vischer Ferry Power Plant on the north side of the river. Before the power plant was built in 1925, Lock 7 generated its own power with two vertical turbine-generators installed in the powerhouse at the upper end of the lock. Construction of the lock began in 1907, the gates and lock equipment were installed in 1910, it was completed in 1911, and it opened in 1913.