Arizona is unlocking an old stash of Colorado River water that its cities socked away before climate change and overuse drained the river of its former excess and cut into the state’s supply.
Salt River Project has cranked open a new, 3.6-mile Gilbert Road Pipeline that will help move groundwater from wells into the Arizona Canal and to Phoenix-area water utilities. That includes Colorado River water that the cities poured into the desert at the Granite Reef Underground Storage Project on the northern edge of Mesa starting in the mid-1990s, when the river could deliver more than Arizona needed.
Between Colorado River water and reclaimed wastewater, Phoenix, Mesa, Scottsdale, Tempe, Gilbert, Chandler and Tempe have stored more than 1 million acre-feet of water in the aquifer there in one of the state’s largest groundwater banks. That’s nearly a third of what the state once took from the river annually, in the years before megadrought imposed a steadily worsening austerity. Those cities now have a way to move their stored water. The 36-inch-wide pipe can deliver it to the canal that flows to city water treatment plants and then to customers…