Drought paradox: Colorado River plants siphon groundwater, trimming river flows

A Princeton-backed study finds that in hot, dry summers vegetation taps groundwater rather than soil moisture, maintaining high evapotranspiration and drawing water away from the Colorado River, thereby reducing basin flows even when snowmelt is abundant. This “drought paradox” suggests climate warming could worsen water shortages and requires revising water budgets and management for the Colorado River basin, impacting states like Arizona and California.