California Gov. Jerry Brown's chief budget adviser says state costs for responding to a winter of brutal storms will likely exceed $1 billion.

Department of Finance Director Michael Cohen said Friday that clearing mudslides and fixing storm-related damage to state highways so far this year will cost California $595 million.

He says there will be several hundred million dollars more for evacuations and non-highway damage, as well as emergency repairs to the damaged spillways at Lake Oroville. He says those costs haven't been precisely tallied.

Cohen says the federal government will cover much of the cost for damage and emergency response.

President Donald Trump's administration has approved federal assistance in response to storms and the damage at Oroville Dam.