The normally placid Lake Powell, the nation’s second-largest reservoir, could suddenly transform into something resembling a funnel, with water circling the openings, the dam’s operators say.And eventually the only water escaping to the Colorado River basin’s southern states and Mexico could be what flows into Lake Powell from the north and sloshes over the lip of the dam’s lowest holes.The chances of hitting minimum power pool (lake elevation 3,490 feet above sea level) within the next two years is part of Reclamation’s minimum probable forecast, and more likely scenarios have water levels staying above that threshold.“The critical part about what’s been happening and what climate change is forcing us to do is: We have to look more at the extremes,” said Tom Buschatzke, director of Arizona’s Department of Water Resources, said in an interview.“We’ve got to plan for the low end.” Reclamation said in a statement it now relies on a more recent 30-year climatology window — 1991 to 2020 — to make forecasts, which leaves out the wet years of the 1980s and incorporates more drought, which “will improve accuracy and remove some biases.” Buschatzke has also been raising the alarm about Lake Powell reaching dead pool — an elevation 120 feet below the threshold for producing power."