Crews rebuilding the Oroville Dam’s main spillway say their work is on schedule as the project passed the midway point for this year. Demolition and reconstruction of the gated flood control spillway began on May 19 and is slated to be finished by Nov. 1. Workers have finished excavations and preparation for the 2,270 feet of the spillway that will be done this year and are now placing reinforced, structural concrete, the state Department of Water Resources reports.