The Lower Colorado River Basin does not avoid a shortage in 2020 despite the plentiful snowpack on the Rocky Mountains this past winter. Why? Well, the new Drought Contingency Plan defines different “tiers” of shortage. The Lower Basin will not drop into a Tier One shortage next year because Lake Mead will almost certainly remain above 1,075 feet in elevation.  At the same time, Mead will likely remain under 1,090 feet. That triggers a Tier Zero shortage.