Work is nearing completion on a fish friendly project on the Truckee river east of Reno, Nevada in the US, that is designed to let fish swim around Derby dam for the first time in more than 90 years.
The US$3.9M fishway is essentially a channel that lets the endangered cui-ui, a threatened Lahontan cutthroat trout, and other species move upstream. The fishway is 283m in length and contains 3380 tons of rock. Large boulders in the middle of the fishway are tuned to control the velocity of water through the channel and to provide a resting spot for the fish.
The design is intended to help the cui-ui, which are not strong swimmers, and to allow the trout to traverse the river from Pyramid lake to Lake Tahoe, something the species has not been able to do in nearly a century.
Derby dam, located along Interstate-80, 32km east of Reno, is important to the Newlands project irrigation district around Fallon because it diverts water from the river to the Truckee Canal.
A fish ladder built at the dam in 1908 never worked and got washed away long ago. The project is expected to be completed by the end of November 2002.