DWR and their contractors received approval from the Federal Energy Regulatory Commission and the California Division of Safety of Dams to resume work on Lake Oroville’s main spillway on May 8.

The first thing you’ll see happen on the main spillway is the removal of the temporary roller-compacted concrete (RCC) walls in the middle section of the main spillway. As a reminder, this year crews will be replacing those temporary walls with permanent, structural concrete walls.

The middle section of the main spillway was reconstructed with temporary RCC. Over the last week, crews have been milling the top layer of the RCC chute to create a uniform surface before placement of steel-reinforced structural concrete slabs. As part of this year’s work, crews will place a three-foot layer of structural concrete on the RCC portion of the chute and will build permanent, structural concrete walls.