A possible megadrought-a prolonged, multidecade period of significantly below-aveage precipitation-would present a major risk to water resources in the American West,which are distbuted through a complex series of local, state and regional water-sharing agreements and laws.Many Western cities will have to fundamentally change how they acquire and use water. Virtually every drop of water flowing in the American West is legaiiy claimed, sometimes by several users,and the demand is expected to increase as the population grows.Some regions will become impossible to farm because of lack of irrigation water. Thermoelectric energy production will compete for limited water resources
There is still time to prevent the worst; the risk of a megadrought in the American West can be reduced if we reduce fossil-fuel emissions. What was once thought to be a future threat is suddenly,catastrophically facing us now.