A top federal water official told Congress on Tuesday that shortages on the Colorado River system have taken an even grimmer turn, with a whopping 2 million to 4 million acre feet of reduction in water use needed by 2023 just to keep Lake Mead functioning and physically capable of delivering drinking water, irrigation and power to millions of people.

Bureau of Reclamation Commissioner Camille Touton testified early Tuesday to the Senate Committee on Energy and Natural Resources Committee that levels at the reservoir have dropped to an all-time low of 28% of capacity, with no relief in sight.

“There is so much to this that is unprecedented,” Touton said. “But unprecedented is now the reality and the normal in which Reclamation must manage our system, for warmer, drier weather is is what we are facing.”