It’s hard to think about floods after five years of drought. But in Sacramento, we don’t have a choice. Scientists tell us that climate change will bring drier years and more severe storms. Recent history shows this threat, as California has bounced between drought and flood. As the recent catastrophic flooding in Baton Rouge, La., makes clear, we can’t wait for rising waters to plan for floods. An overhaul in how California prepares for and manages floods is long overdue.