PG&E Repairs Powerhouse, Flows Resume to Water Agencies in Nevada, Placer Counties

By Paul Moreno

Water is again flowing to water agencies in Nevada and Placer counties following repairs to one of two water discharge liners at PG&E's Spaulding 1 powerhouse near Lake Spaulding.

After several days of testing and inspection, the powerhouse is back in partial service and ahead of the scheduled date of July 30. The repairs to the first discharge pipe allow the unit to pass flow of about 450 cubic feet per second (cfs). Flows out of the powerhouse empty into the Drum Canal, which feeds the Nevada Irrigation District's (NID) Rollins Reservoir. Placer County Water Agency (PCWA) also draws water from Rollins Reservoir.

PG&E is also diverting about 60 cfs from the Drum Canal into the district's South Yuba Canal, which feeds into its Scotts Flat Reservoir.

"PG&E worked 24/7 to make the necessary repairs so we could restore flows as quickly as possible," said Dave Gabbard, PG&E vice president, Power Generation. "This was a very large, complex project as we discovered more extensive damage as the project progressed. I'm proud of our team as it moved with urgency and tenacity, and most importantly completed the work safely."

Meanwhile, at the South Yuba Pipe - which connects PG&E's Spaulding 2 powerhouse to the district's South Yuba Canal - PG&E is awaiting the availability of a type 1 heavy-lift helicopter to place six large steel pipe segments into place.

A 240-foot segment of the South Yuba Pipe was damaged in a winter rockslide. Challenging terrain, loose rocks, debris, and snow had blocked safe access for crews to assess the damage until mid-spring. Once cleared, crews installed scaffolding and forms and then poured concrete for footings to support the pipe.

Heavy-lift helicopters capable of lifting over 17,000 pounds have been diverted to support critical state and federal agencies' firefighting needs as a result of the increased national fire activity. PG&E's aviation services department currently has a heavy-lift helicopter scheduled for early August barring any additional diversion, and the crew to perform the work is ready to engage when a helicopter becomes available.

After the pipe is in place, crews will weld the pipe and attach collars. The South Yuba Pipe is expected to be restored in mid-September, providing about 80 to 100 cfs to the South Yuba Canal.

PG&E is working with water agencies to develop a schedule to repair the second water discharge liner at Spaulding 1 powerhouse as it will require an outage on Spaulding 1 powerhouse and limit outflow from Lake Spaulding.