Yuba Water Agency Awards Initial Penstock Engineering Contract

DOBBINS — The Yuba Water Agency awarded a contract on May 11 to GFT Inc. for engineering and design services tied to the penstock pipe that ruptured above New Colgate Powerhouse. The initial agreement totals nearly $2 million and covers a thorough condition assessment of the penstock, as well as an alternatives analysis. Officials estimate that an additional $6 million will fund detailed engineering design and support during eventual construction.

The penstock serves as a critical 14-foot-diameter pipe roughly one mile long. It conveys water from a five-mile rock tunnel connected to New Bullards Bar Dam and Reservoir down to New Colgate Powerhouse on the North Yuba River near Dobbins. Water flowing through the pipe spins turbines inside the powerhouse to generate electricity sold into the power grid.

A catastrophic failure of the penstock released approximately 400 acre-feet of water down the hillside during scheduled maintenance on February 13. The surge caused major erosion, damaged the powerhouse and shared switchyards, washed out sections of Lake Francis Road, and carried debris into the Yuba River. The Yuba Water Agency continues to operate the site without power generation, and officials project the powerhouse will stay offline for the foreseeable future, potentially several years.

The awarded contract marks an early step in the penstock reconstruction process. Forensic engineers are still investigating the exact cause of the rupture, with results expected in fall 2026. Bryan Perrin, Yuba Water’s project manager for the work, stated, “While this contract does not cover the actual construction of the repaired penstock, it does position us to move quickly once we have the results from the forensic investigation.” He added, “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.”

Separate restoration work proceeds in parallel at the site. Yuba Water Agency contracted with Nordic Industries to repair Lake Francis Road in phases and restore safe access. Crews have removed thousands of cubic yards of mud and sediment from the powerhouse deck and continue hillside stabilization efforts. Sediment removal from the North Yuba River upstream and downstream of the facility is scheduled to begin later this month.

Full reconstruction of the penstock will depend on the investigation findings, condition assessment, and alternative analysis. No firm timeline for completion exists yet, though agency leaders emphasize steady progress across all restoration phases. Readers can track updates through the Colgate Powerhouse and Infrastructure Restoration Project page at tmmlink.com/qdgrrNQ.