Lone Rock Utah

How to Define a Drought?

Some consider drought to occur in the Colorado River Basin when water supplies reach drought level (2nd line down on the left graph of Lake Mead's recent elevations), and others may define it in various other ways.  The National Drought Mitigation Center at the Unversity of Nebraska/Lincoln, after declaring that drought is indeed difficult to define, says In the most general sense, drought originates from a deficiency of precipitation over an extended period of time - usually a season or more . .    We use this as evidence for our declaration of a 22-year drought (2022).

The graph segment on the left shows the deepest and longest-term decline of Lake Mead since it started filling in 1937 to its lowest level ever - down 177.8 feet (54.2 m) on July 17, 2022 (date of the graph).  Drought-level is the 2nd red line from the top of the graph.

The July 17, 2022 graph segment of Lake Powell on the right is strikingly similar.  Lake Powell reached its lowest level ever on April 22, 2022, down 177.8 ft (54.2 m).  The 2022 snowmelt raised the Lake Powell elevation by only 17.6 ft (5.4 m).  Historic snowmelt elevation increases were generally in the 40-50 ft (12-15 m) range.

Drought Updates continues this story with recent graphs and 5 years history for the lakes, 7 years for snowpack.  2000-2022 cycling images illustrate the extent of the drought and its water loss for Lake Powell and Lake Mead (from Satellite Images).

Lake Powell 2000-2022