California’s Most Significant Droughts: Comparing Historical and Recent Conditions

This report was prepared in response to the dry conditions of 2012-14 (Figure 1.1) and particularly in response to the very dry hydrology of water year 2014. Water year 2014 ranked as the third driest on record in terms of statewide precipitation, with the three-year period of water years 2012-14 ranking as the driest consecutive three-year period on record in terms of statewide precipitation.

Continuing dry hydrology in 2015 raises questions about the similarity of present conditions to those of prior droughts and changes in observed impacts as California’s population increases and new institutional requirements are put in place. The purpose of this report is to compare present conditions with California’s most significant droughts of statewide scope, to help answer questions about the comparative severity of drought hydrology and drought impacts. The report also summarizes lessons learned and commonalities seen in the state’s most severe historical droughts.