Yuba Water Agency moves forward with penstock rebuild after massive rupture
Yuba Water Agency has awarded an engineering contract worth up to $8 million as it begins planning to rebuild the penstock pipe that ruptured above New Colgate Powerhouse in February.
The agency selected GFT Inc. to conduct engineering and design services related to the damaged penstock. A penstock is a large, pressurized pipe that carries water from a reservoir into a hydropower plant and then back into the river.
The penstock rupture occurred Feb. 13, when a 15-foot-diameter section of pipe failed above New Colgate Powerhouse, releasing an estimated 400 acre-feet of water down the hillside. The surge triggered severe erosion, damaged the powerhouse and nearby switchyards, washed debris into the North Yuba River and destroyed portions of Lake Francis Road.
It also led to the deaths of hundreds, possibly thousands, of juvenile salmon after lower Yuba’s river flows dropped by more than half, stranding fish along the margins of the river, according to previous Bee reporting.
The initial contract, valued at nearly $2 million, covers assessment and preliminary analysis work. Yuba Water estimates an additional $6 million will be needed for detailed engineering design and construction support. Officials said final repair costs and a timeline for rebuilding will depend on the results of an ongoing forensic investigation into the rupture.
Bryan Perrin, Yuba Water’s project manager, said this puts them in a position to move quickly.
“Our goal is to take what we learn from the investigation, develop engineering design plans and award a future construction contract to rebuild the penstock and get us back in business,” he said.
The powerhouse is expected to remain offline for years while repairs and restoration work continue, according to the agency.
Yuba Water said forensic engineers are continuing to investigate the cause of the rupture, with findings expected this fall. California workplace safety inspectors have also opened an investigation into the incident involving Yuba Water Agency and Elite Universal Security, according to previous Bee reporting.
In the meantime, the agency is advancing multiple recovery projects tied to the Colgate Powerhouse and Infrastructure Restoration Project, including rebuilding Lake Francis Road, stabilizing the hillside above the powerhouse, restoring the powerhouse, removing sediment from the river and reconstructing the penstock.
Yuba Water also awarded a separate contract to Yuba County-based Nordic Industries to repair portions of Lake Francis Road that were washed out during the rupture and subsequent erosion. Crews are working in phases to restore access, beginning with utility vehicles and eventually reopening the road to regular traffic. The road remains closed to the public beyond the last residence.
Officials said crews are also removing an estimated 11,000 cubic yards of mud and sediment deposited around the powerhouse, where debris reached depths of more than 13 feet in some areas. Additional sediment removal along the river is expected to begin in May.
Despite the extensive damage, agency officials said the interior of the powerhouse was not completely inundated by water or mudslides.
This story was originally published May 12, 2026 at 9:30 AM with the headline "Yuba Water Agency moves forward with penstock rebuild after massive rupture."
