Road damage from storms that have slammed Marin since January will cost $8.7 million to repair 24 sites, according to a county report to the Board of Supervisors on Tuesday. “It seems like a storm hit every weekend,” said Raul Rojas, head of the Department of Public Works. Projects include an estimated $980,000 to repair Lucas Valley Road just off Nicasio Valley Road and $800,000 to repair White Hill, where slides closed traffic four times in the past month. “This is one of the most difficult sites I’ve ever seen in the county,” Ernest Klock, the department’s principal civil engineer, said of the hill. At one point, he said, when they went above the slide to look for water, they were surprised to find “no surface water at all”; subsurface water had destabilized the hill. Along Fairfax-Bolinas Road, Mr. Klock counted about 20 unstable sites; repairs are estimated to cost $200,000. Although that road is closed to all traffic, he said cyclists are still using it. “I just want to warn the public that is not safe to go through there,” he said. Part of Conifer Way in Woodacre and Forest Drive in Forest Knolls remain closed, and will cost $500,000 and $200,000, respectively, to repair. Repairs could be aided by funds from the Federal Emergency Management Authority and the Federal Highway Administration. “It’s not that we will get every dollar back, because that’s not how it works, but we hope to get a significant amount back,” Mr. Rojas said. But it can take two years or longer before funds come through. Mr. Klock said the federal government recognized the January storms, but not the February storms, as a federal emergency, but the county is preparing a plan B. Matthew Hymel, the county administrator, said the county is repairing all roads considered essential for public safety. “For the other ones, what we would be doing is getting some sense of a high probability of federal or state reimbursement, and then we would work with the Department of Finance to appropriate funds on those projects. But we would also have a reserve for disallowances,” he said, “because FEMA is kind of famous for two years later taking away the money.”