Gate fails at Leaburg Dam

Engineers investigate Leaburg Dam gate problem

Eugene Water & Electric Board engineers and operations personnel are looking into why one of three roll gates at Leaburg Dam stopped working on Tuesday, Dec. 23.

The unexpected shutdown of the gate is the second to fail in the past three years. The middle roll gate experienced a failure in January 2012 and is currently being repaired at the 73-year-old hydroelectric facility on the McKenzie River. The three 16-feet-tall by 100-feet-wide gates regulate the volume of water spilled from the dam on the river east of Eugene.

Shutdown of the right-bank roll gate poses no immediate threat to the public. The remaining operational gate, plus an overflow spillway, can pass more than 31,000 cubic feet per second of water – more than the river volume forecast for another rainstorm expected to hit the area on Wednesday. The long-term forecast beyond Wednesday calls for less precipitation and even a drying trend into next week.

EWEB officials are not yet certain why Roll Gate No. 1 closed unexpectedly on Tuesday morning. The closure was similar to the failure of the motor system at the middle roll gate nearly three years ago. Repairs to the middle roll gate should be completed by mid-January, increasing the flow capacity to about 52,000 cfs – more than the biggest flood that occurs once every 100 years, on average.

The gates have a unique system or opening and closing. They are cylindrical steel that “roll” or rotate, up and down, to regulate the flow of the river. Water also is diverted at Leaburg Dam into a power canal that is used to generate electricity at a powerhouse four miles downstream. The dam was constructed in 1931.