Historic drought has reduced Lake Mendocino to its second-lowest level since it was built, leaving reservoir storage in startling condition with months of likely warm, dry weather still ahead.

The lake on Thursday held just more than 24,000 acre feet of water — a result of critically low rainfall totals that, combined, make 2019-21 the driest two years on record, the National Weather Service said.

Storage in the reservoir, completed in 1958 with a flood storage capacity of 122,400 acre feet, has dipped below 25,000 acre feet only three times before and below 24,000 acre feet only once — by half, according to Sonoma Water.