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Wildfire curtails hydro power generation from Middle Fork American River Project

Wildfire curtails hydro power generation from Middle Fork American River Project

Energy generation from the Middle Fork American River Project in California “has been severely curtailed,” by the Mosquito Fire, said Placer County Water Agency’s General Manager Andy Fecko.

The board received a report from PCWA staff on the progress of the Mosquito Fire and status of the project, which is located within the fire’s footprint, on September 15.

The Mosquito Fire erupted on the evening of September 6 near Oxbow Reservoir in the Tahoe National Forest. Since that time, PCWA has evacuated all employees from the area, coordinated with emergency responders on the location and protection of agency assets, and opened its facilities in Foresthill and Auburn to personnel working on the front lines of the fire.

 “While damage to the project cannot be fully assessed at this time, we can report that energy generation has been severely curtailed,” Fecko said. “As of this morning, our top concern is our largest powerhouse, the Middle Fork Powerhouse, which is located within a mile of the fire’s eastern boundary.”

The Middle Fork Project is located in Placer and El Dorado counties and on the Middle Fork of the American River, Rubicon River, Duncan Creek and North and South Fork Long Canyon creeks. It includes seven dams — Duncan Creek diversion dam, French Meadows dam, Hell Hole dam, North Fork Long Canyon Creek diversion dam, South Fork Long Canyon Creek diversion dam, Middle Fork interbay dam and Ralston afterbay dam — and five powerhouses: 15.3 MW French Meadows, 725 kW Hell Hole, 61.2 MW Middle Fork, 79.2 MW Ralston and 6.128 MW Oxbow.

The overall project is operated in a seasonal store and release mode and has an average annual generation of about 1,039,078 MWh.

Despite losing the ability to generate power, the agency continues to meet its minimum stream flow requirements out of Middle Fork and Oxbow powerhouses, keeping water flowing and available for fire-fighting efforts, according to a release. So far, there is no impact to water supply or water service for PCWA customers.

“The Mosquito Fire is the type of fire PCWA has been concerned about for the last decade, and the reason we take protection of our watershed so seriously,” Fecko said. “Experience has shown that the impacts to our rivers, hydroelectric facilities, and ecosystem will take years to remediate and cost tens of millions of dollars. The action taken by the PCWA Board today will allow the agency to expedite emergency repairs on the project once conditions allow. Safety of staff and customers remains our highest priority.”

By mid-September, the Mosquito Fire had reached just over 64,000 acres with 20% containment according to InciWeb, the national incident information system for wildfires and all hazard incidents.

PCWA is the primary water resource agency for Placer County, Calif., with responsibilities including water resource planning and management, retail and wholesale supply of drinking and irrigation water, and production of hydroelectric energy.