A major flash flood at the Grand Canyon forced the evacuation of dozens of people and knocked out the sole water pipeline serving tourists and residents. Starting Monday, tourists won't be able to stay overnight at lodges and hotels in the national park. Year-round residents are being asked to conserve water. The National Park Service says flash flooding Saturday also swept large boulders and metal structures into the Colorado River. No injuries were reported. But park officials say they have yet to account for about 15 people. They've asked anyone with details about hikers or campers who were in the canyon to get in touch. More rain was possible Monday.

Mayor Robert Morris of Cave Creek, Arizona, is worried about more water shortages from the severely depleted Colorado River. The federal government recently finalized a new river plan to help keep it from plunging further, causing concerns and uncertainty among those who rely on its water. Nevada raised the stakes by suing the federal government over the new rules. Even farmers not facing cuts are struggling to plan what to plant and how much due to the uncertainty. Climate change is reducing snowpack and water supplies, and 10 reservoirs across the West are at their lowest in at least 30 years.