Cleanup Efforts Underway Following Colgate Penstock Pipe Failure
Agencies coordinate debris removal, oil containment, and monitoring after the Yuba River pipeline rupture.
Crews work to remove debris from the Yuba River. Efforts are headed by agencies including the California Office of Spill Prevention and Response, the Yuba Water Agency, and others. Credit: Yuba Water Agency.
YUBA RIVER — Crews from multiple agencies continue to remove debris and contain petroleum products in the Yuba River after a penstock pipe rupture at the New Colgate Powerhouse operated by the Yuba Water Agency. The failure occurred on February 13, just before 3 PM, in the community of Dobbins along the North Yuba River. Significant amounts of sediment, man-made debris, and oil entered the waterway upstream of Englebright Lake.
The Yuba Water Agency described the event as a catastrophic rupture of the 14-foot-diameter penstock pipe above the powerhouse. Water stored in the five-mile-long rock tunnel and one-mile-long penstock, estimated at about 400 acre-feet, rushed downhill during testing of a newly installed section. The release triggered flooding and a mudslide that damaged portions of the powerhouse, eroded the hillside, and affected nearby Lake Francis Road and Pacific Gas and Electric transmission lines.
River conditions immediately downstream showed elevated turbidity, with suspended sediment creating cloudy water that reduced visibility and scattered light. Observers noted floating and submerged debris, including woody material and other items swept from the site, along with an oil sheen reported at the point where the river enters Englebright Lake. According to sampling conducted by the South Yuba River Citizens League at Rice’s Crossing and a control site at Bridgeport, turbidity levels rose noticeably while dissolved oxygen and pH remained within normal ranges compared to 25 years of baseline data.
Cleanup operations began within hours of the incident. By February 14, Yuba Water Agency crews, working with environmental contractor Clean Harbors and in coordination with the U.S. Army Corps of Engineers, conducted helicopter surveys to map debris and positioned boats on Englebright Lake. An oil boom and multiple debris booms were installed across the lake by February 15. Large debris items were removed from accessible sections of the river and reservoir, with efforts accelerating through the use of barges for large-scale operations in the lake.
Damage from the burst penstock pipe near Dobbins contaminated the river. Credit: Yuba Water Agency.
The California Department of Fish and Wildlife and its Office of Spill Prevention and Response joined the response to address the oil sheen. A Unified Command structure was formed between the Yuba Water Agency and the Office of Spill Prevention and Response to oversee containment and removal of oily materials. No visibly oiled wildlife has been reported. Water quality monitoring and laboratory testing continue at multiple sites across the watershed, with results expedited to track any changes.
A report published by The Sacramento Bee indicated that some salmon may have been killed due to a drop in water flow after the rupture. The publication cited field observations by the South Yuba River Citizens League of hundreds or possibly thousands of juvenile Chinook salmon found dead in the lower Yuba River. The report attributed the mortality to a sudden reduction in flows from Englebright Dam, which dropped by more than half and remained low for roughly 2 hours, stranding young fish along river margins. The Yuba Water Agency has confirmed awareness of such reports and works with the California Department of Fish and Wildlife and the South Yuba River Citizens League to assess impacts on conditions in the lower Yuba River, including fish mortality. Experts cited in the Sacramento Bee report expect the salmon runs to recover, given recent wet years and strong adult salmon returns.
A SYRCL team member collects a sample from the river for independent analysis. Credit: SYRCL.
The Yuba Water Agency maintains a water quality monitoring plan and conducts regular sampling. The South Yuba River Citizens League continues independent field measurements at key locations to supplement official data. Geotechnical experts have completed preliminary assessments of hillside stability, and a LiDAR survey of the affected area provides detailed imagery for comparison with prior scans.
Yuba County proclaimed a local emergency on February 20 to strengthen environmental monitoring and inter-agency coordination. County Administrator Kevin Mallen cited the presence of hazardous materials and debris in the river as the basis for the declaration, which facilitates resource requests without indicating immediate public safety threats downstream.
Long-term stabilization of the hillside and full assessment of damage to the penstock and powerhouse remain priorities. The Yuba Water Agency expects thorough damage evaluations and development of a recovery plan to require several weeks to months.
Cleanup activities will continue with debris and oil removal, ongoing water quality sampling, and environmental assessments until impacts are mitigated to agency standards. The Yuba Water Agency has committed to regular public updates on progress through its website and official channels. The U.S. Army Corps of Engineers continues to manage Englebright Lake operations in support of these efforts, and the public has been advised to avoid the river section between the powerhouse and the lake due to potential hazards.