New digital tool shows exactly where California's water goes—and how climate change might disrupt it

Water has always been one of California's most contested resources. For more than a century, battles have raged over how much of the state's water should be diverted to farmland, pumped into cities or used to conserve aquatic ecosystems—and at times, these clashes have even led to violence. The state's water system consists of a dizzying array of reservoirs, rivers, dams and aqueducts, making it challenging even for experts to understand the trade-offs of different management decisions.