While desalinated water has grown less expensive since its inception, it still tends to be far more pricey than conventional water sources. For San Diego area residents, water from the Colorado River costs about $1,100 per acre-foot, while desalinated water costs about $2,200 for the same amount, says Fiske. (According to a recent report, though, that desalinated water is getting even pricier, at $2,685 per acre foot in June 2019.) Since the plant began delivering water in 2015, residents pay about $5 more a month in their water bills. Despite that stark difference, Fiske says that local water managers believe that the cost is worth it to have a water source that won’t change with the warming climate.