Phoenix isn’t the only city in the Southwest grappling with extreme heat and water shortages. Las Vegas and Los Angeles are also feeling the strain as the Colorado River — a lifeblood for millions in the region — shrinks due to rising temperatures, overuse, and a lack of snow migrating down from the Rocky Mountains. Without drastic changes to water management and conservation, these cities could face unsustainable conditions in the decades ahead. This particular problem is urgent, as the current agreement about how to divide up water usage from the river ends in 2026.