Project Update: Derby Dam Horizontal Fish Screen Project

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Construction is in full swing on a $34-million fish screen at Derby Dam, 21 miles east of Sparks, Nevada, on the Truckee River. The screen is the final piece in a major fish passage project to restore habitat connectivity for native fish species. The overall project has three components (1) an upstream fish passage channel on the north side (river left bank) of Derby Dam that was completed in 2003, (2) automation of two Derby Dam River gates to maintain suitable fish passage channel water velocities which were completed in 2019, and (3) a screen on the Truckee Canal to allow for entrained fish to safely return to the Truckee River.

In Phase 1 of the fish screen project, a key construction milestone was the completion of a screen bypass channel that allows water deliveries to downstream users in the Newlands Project via the Truckee Canal while screen construction continues. The bypass channel is providing irrigation water to the communities of Fernley and Fallon, Nevada, for their 2020 farming season. It also supplies water to wetlands at the Stillwater National Wildlife Refuge and Pyramid Lake Paiute Tribe with irrigation rights. The bypass channel will also provide future operational flexibility during screen maintenance.

Phase 2 of the fish screen project is in progress with the construction of the concrete structure that will house the horizontal fish screens.

The new fish screen will support safe fish passage along the Truckee River between Pyramid Lake and Lake Tahoe, promoting the recovery of the federally-listed, threatened Lahontan Cutthroat Trout Oncorhynchus clarkii henshawi (LCT), as well as fishing and recreation opportunities in Nevada.

Completed in 1905, Derby Dam was the first project of the newly formed U.S. Reclamation Service (now Bureau of Reclamation) organized under the Reclamation Act of 1902. Derby Dam is 31 feet high and has a crest length of 1,331 feet. Historically, fish ladders constructed and operated at the dam (1905-1941) were ineffective and periodically damaged by flooding.

Lahontan Cutthroat Trout in the Truckee Basin were an important food source for Native Americans and were once so numerous that a robust commercial fishery existed. The last known historical Truckee River run of adfluvial LCT from Pyramid Lake was in 1938 and by 1944 they were considered extirpated due to overharvesting, habitat degradation, and physical barriers preventing access to upstream spawning habitat. Since 1998, stocking of adfluvial LCT with genetics from the historical Pyramid Lake population has occurred by Federal and State agencies and Tribes, and annual LCT spawning runs are increasing.

Reclamation and the U.S. Fish and Wildlife Service (USFWS) have partnered in the design and operation of the Derby Dam Fish Passage project. The USFWS’ Lahontan National Fish Hatchery Complex provided technical assistance on innovative fish screen technology, and the Farmers Conservation Alliance’s (FCA) horizontal plate fish screen was selected by the agencies.  Reclamation funded the screen construction.

Upon completion of the fish screen construction in the fall of 2020, the Derby Dam Fish Passage project will provide safe fish passage both upstream and downstream of the dam. This project will facilitate the recovery of LCT in Pyramid Lake and the Truckee River, which has been a collaborative effort between multiple stakeholders and agencies.

To learn more about FCA, the Derby Dam Fish Passage project and to view the fish screen live construction cam, visit:

Photo credit: Farmers Conservation Alliance | Granite

Drone footage from April 21

Webcam Construction footage from April 13