With the level of Lake Mead dipping below 1,075 feet on Tuesday and forecast to drop further, it is nearly certain that the Bureau of Reclamation will declare a Tier 1 shortage later this summer.
1,075 feet is the cut off. Below that, it’s an emergency. A Tier 1 water shortage means Arizona farms will be hit hardest. Arizona's main population centers will be spared. California's water deliveries would not be impacted in a Tier 1 shortage, according to the drought contingency plan.
The U.S. Bureau of Reclamation projects that a Tier 2 water shortage could be declared in late 2022 and into 2023.