How Climate Change Is Drying up the Western US

Water across the Western US comes largely from mountain snowpack, which acts as a natural reservoir, holding winter moisture until it melts in spring and summer. This year, snowpack across California, the Colorado Basin, and the Pacific Northwest hit record or near-record lows, a pattern made four times more likely by climate change. A warm winter, rain falling on top of snow, and a record spring heat wave melted the little snow that fell even faster. Lake Mead recently dropped to its lowest level ever recorded, and thin snowpack raises fire risk by drying out forests and grasslands earlier in the year.

Most Western water goes to agriculture, not household use — as much as 90 percent in California's San Joaquin Valley. As temperatures rise, crops and soil lose more water to the air, a process called evapotranspiration, pushing farmers to pump more groundwater when river and snowmelt supplies fall short. Decades of heavy groundwater pumping have already caused the ground itself to sink in parts of the San Joaquin Valley, and rural households with shallow wells are often the first to run dry when supplies get tight.

None of this points to a simple fix homeowners can act on directly. Proposals on the table include expanding reservoirs in California and pairing solar panels with canals or farmland to cut evaporation while generating clean power. But the piece makes clear that personal water-saving habits, like shorter showers, are a small piece of a much larger system strained by rising heat and demand — one that ultimately depends on how aggressively climate change itself gets addressed.