Sediment Removal Begins Below Colgate Powerhouse on Yuba River
Cleanup aims to restore river capacity and support safe powerhouse operations after February rupture.
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Cleanup crews at work near the New Colgate powerhouse in the Dobbins area. Credit: Yuba Water Agency.
DOBBINS — Yuba Water Agency has launched work to clear deposited sediment from the North Yuba River following a major penstock pipe rupture earlier this year. Crews started the effort in May near New Colgate Powerhouse in Dobbins and expect it to continue for several weeks or months.
The February 13 rupture sent roughly 400 acre-feet of water rushing down a hillside. That surge eroded soil and rock, swept debris into the river upstream of Englebright Lake, and damaged the powerhouse, switchyards, and Lake Francis Road. About 60,000 cubic yards of sediment now sit in two large fans on either side of the facility.
Yuba Water Agency crews are carefully excavating the material from the riverbank and channel. Officials said the removal will restore the river’s normal capacity and allow safe resumption of powerhouse operations ahead of winter flows. “We’re doing everything we can to minimize turbidity, both in how long it might last and how cloudy the water gets,” the agency stated in a public release. “We’re also increasing our water quality monitoring during this time so we can respond to changing conditions appropriately.”
Recreators may notice cloudier water below the powerhouse temporarily, possibly extending into Englebright Lake. The agency urged patience and reminded the public that Lake Francis Road remains closed beyond the last residence. Englebright Lake reopened to the public in mid-March after debris removal was completed.
Inside the powerhouse, teams have already removed roughly 11,000 cubic yards of mud and sediment from the deck, where deposits reached more than 13 feet deep in places. Workers cleaned and tested interior systems, though full electricity generation remains suspended for the foreseeable future. Phased repairs on Lake Francis Road also continue under a contract with Nordic Industries.
A recent photo of the New Colgate powerhouse facility shared by Yuba Water Agency.
The broader restoration project has a ways to go. Forensic engineers continue to investigate the cause of the rupture, with findings expected in fall 2026. Yuba Water Agency awarded a design contract in May to GFT Inc. for planning the penstock rebuild. Additional work will stabilize the eroded hillside to prevent future sediment movement into the river. The full recovery of the Yuba River Development Project facilities could take years.
Yuba Water Agency leads the overall response and coordinates with the U.S. Army Corps of Engineers, which owns and operates Englebright Lake. Water quality tests so far have shown no detections of hazardous contaminants such as PCBs or petroleum hydrocarbons. The agency continues to update the public at engage.yubawater.org.