A power industry consulting firm has proposed a design for the Oroville Dam spillways which involves not repairing the current one, but building a new, wider spillway. The designer says the structure’s capacity would handle flows of 300,000 cubic-feet per second. Kenneth Viney, manager of CoastalGen Inc., based in Napa, filed suggestions Monday with the Federal Energy Regulatory Commission, or FERC. He said he first shared his ideas with engineers with the state Department of Water Resources about a month ago and was encouraged by FERC and DWR spokespeople to submit his plans through a FERC filing.