A civil engineer who formerly worked for the contractor doing the Oroville Dam spillway reconstruction has proposed a dual design spillway so the emergency spillway never has to be used again. Henry Burke’s argument for a different design than what the state Department of Water Resources proposed, centers around the need for high-flow back ups. Burke used to work for the contractor, the Kiewit Corporation, which is based in Omaha. Erin Mellon, communications manager with the Natural Resources Agency, said his concept is being considered in the long term, though not by Nov. 1 this year.