The Mongaup River System consists of five reservoirs and three hydroelectric stations that work in combination to use the available water resources from the 200 square mile Mongaup River Basin to provide nearly 60 million kilowatt-hours of clean electric power each year for the citizens of New York State and beyond.
Swinging Bridge is a 6,750-kilowatt facility and is the most upstream of the power generating stations on the Mongaup River. Swinging Bridge Dam was built in 1930, and Powerhouse 1, containing a 5,000 kilowatt turbine/generator, was commissioned at that time and operated until it was permanantly retired in 2005. Powerhouse 2, containing the 6,750 kilowatt turbine/generator, was commissioned in 1937 and is still in operation today. The Swinging Bridge Project, as licensed by the Federal Energy Regulatory Commission (FERC), also includes Toronto Reservoir and Cliff Lake on Black Lake Creek. Water from Toronto Reservoir flows downstream to Cliff Lake, from which a portion of the water is diverted via underground tunnel to Swinging Bridge Reservoir.
Swinging Bridge Reservoir and Toronto Reservoir are the largest reservoirs in the system at approximately 900 acres each. They are the only two reservoirs that allow power boating, and the only two that have homes and developments on them. Swinging Bridge is licensed by the FERC (Project No. 10482) through 2022.
Mongaup Falls, a 4,000 kilowatt station, was the first power station to be developed on the Mongaup River. The dam and powerhouse, with three 1,000 kilowatt turbine/generator units, were completed in 1923. A fourth unit was added in 1927. Mongaup Falls is downstream of the confluence of the Mongaup River and Black Lake Creek. A dam on Black Brook, to the east, formerly diverted water from that stream into the Mongaup Falls project as well, but that diversion was taken out of service in the 1980s. Mongaup Falls is licensed by the FERC (Project No. 10481) through 2022.
Rio, a 10,800 kilowatt station downstream of Mongaup Falls, was the second development on the Mongaup River. It was completed in 1927 with the existing dam, 7,000 foot penstock (pipeline), and powerhouse containing two 5,000 kilowatt turbine/generator units. The configuration of the plant means that the water used for generating power originally bypassed nearly two miles of the Mongaup River between the dam and the powerhouse. Beginning in 1994, the project released a portion of the water at the base of the dam to maintain flow in the Mongaup River. In 2013, Eagle Creek completed construction of a new 800 kilowatt turbine/generator unit in a new powerhouse near the base of the dam to generate additional power from this water that does not flow through the main generating units. The Rio Station now makes efficient use of all of the water in the Mongaup River while maintaining acquatic habitat from the Delaware River all the way up to the base of the Rio Dam.
The Mongaup River downstream of Rio contains a section of rapids popular for whitewater kayaking when one or both main turbines are online. Although Eagle Creek generally does not publish its generating schedule in advance, there is a streamflow gage near the put-in point, and Eagle Creek does schedule certain water releases every other weekend from April through October. More information is available on the Whitewater Recreation page.
Rio is licensed by the FERC (Project No. 9690) through 2022.