Construction of the Derby Dam fish screen will restore watershed connectivity and support fish movement along the Truckee River, promoting both the recovery of the federally threatened Lahontan Cutthroat Trout, as well as fishing and recreation opportunities in Nevada.
The construction of Derby Dam, completed in 1905, was the first project of the newly formed U.S. Reclamation Service (now Bureau of Reclamation) organized under the Reclamation Act of 1902. Lahontan Cutthroat Trout (LCT) in the Truckee Basin were once so numerous that a robust commercial fishery existed. After the completion of Derby Dam in 1905, LCT lost access to their spawning habitat, which eventually led to their extirpation in the Truckee Basin.
The Fishway project has three components (1) the Fish Passage on River left of the Derby Dam structure, (2) modification to automate two Derby Dam River Gates to maintain the required pool to allow the correct water flow through the Fish Passage, and (3) a Fish Screen to allow for fish entrained in the Truckee Canal to return to the Truckee River.
In 2001, Reclamation and USFWS designed and completed a fish bypass around Derby Dam. The Lahontan National Fish Hatchery Complex (LNFHC) and Reclamation began reviewing different fish screen designs to implement the fish protection portion of the Derby Dam fish passage improvements. Staff from the LNFHC took part in Reclamation’s value engineering study, and suggested using an innovative technology: Farmers Conservation Alliance’s horizontal plate fish screen was chosen to move forward.
Combining the biological expertise of the US Fish and Wildlife Service, with the engineering and construction expertise of the Bureau of Reclamation, and the innovative technology and ability to perform of the Farmer’s Conservation Alliance has made this effort possible.
In the 1970’s an out-of-basin population of LCT was discovered on the border of Utah and Nevada in the Pilot Peak Mountains. Taxonomists at the time thought that it originated from the original Pyramid Lake population that was native to the Truckee Basin. Beginning in 1995 LNFHC developed a conservation broodstock intended for use in recovery efforts in the Truckee Basin system.
Concurrent with the development of the broodstock, LNFHC funded genetic research to compare the broodstock population with original museum mounts of the original Pyramid Lake population. Genetic analysis confirmed that the Pilot Peak LCT represented the original populations found in Pyramid Lake and Lake Tahoe. In 2006, working in partnership with the Pyramid Lake Paiute Tribe (PLPT), the LNFHC began stocking these iconic trout in Pyramid Lake.
Remarkably, Pilot Peak LCT were observed spawning in 2014, the first time natural reproduction of LCT had been documented in over 80 years. The numbers of Pilot Peak LCT migrating from Pyramid Lake into the Truckee River has grown from those first ten individuals to a record number of 775 Pilot Peak LCT in 2019.