It’s raining in Los Angeles. That’s news in a place that’s been dry for several months. And historically, when it rains in LA, the water whooshes out into the ocean as fast as possible. But local leaders are changing how they think about rain. Now they want to catch it, keep it and store it for future use on less rainy days, and do all this in a way that is attractive to the public and makes our flood control systems destinations in themselves.