As waterlogged storms repeatedly pounded California this winter, social media was filled with variations on a distinct photo theme. The subject was a freshly-plowed road, wedged in between towering white walls of snow measuring 10, 20 feet tall. As long as vehicles had safe passage, a wintry trench would be fine – that snow had to go somewhere, after all. But with an early-spring heatwave in the forecast, it’s time to start thinking about what a massive amount of snowmelt will mean for the state – that water has to go somewhere, after all.