Work is underway right now at the Oroville Dam spillway, but many questions remain. How much will it cost? Will repairs be complete in time for the rainy season? Will life under the shadow of the dam return to normal?The best answer is that it’s a work in progress. So far, an estimate for repairs has reached $500 million, said Erin Mellon, communications and outreach adviser for the state Natural Resources Agency. The hope is that the Federal Emergency Management Agency (FEMA) will help pay for 75 percent of eligible emergency response and repairs, Mellon said.