The second and final phase of reconstruction continues at the Oroville Dam spillways. This year, contractor Kiewit Infrastructure West Co. is rebuilding the top 730-foot portion of the main spillway and using structural concrete to rebuild the walls and resurface the chute in the middle. A flight over the location last week during a break in Butte County Sheriff’s Office helicopter training exercise, showed that much original concrete at the top of the chute has been removed, along with the walls.