Los Angeles did something Tuesday it’s never done before: it prohibited about 6 million Angelenos from watering outdoor landscapes except for one day a week.

That’s because climate change-driven drought in California has stretched into its third year, with less rain and snow from the Sierra Nevada mountains feeding the northern rivers of the state. And that means the state’s biggest water lifeline, called the State Water Project, has less water to deliver to the thirsty lands and people who rely on it throughout the rest of California.