The tunnel is over 18 miles (29 kilometres) in length, and spans through Greene County and Ulster County, and water is forced through the tunnel by gravity; it slowly declines at a rate of 4.4 feet per mile.
The tunnel is over 18 miles (29 kilometres) in length. The tunnel is over spans through Greene County and Ulster County. Water is forced through the tunnel by gravity. It slowly declines at a rate of 4.4 feet per mile.