But despite the brief respite, experts say the record drought is here to stay.

The El Nino weather phenomenon—caused when a rise in the Pacific Ocean's temperature triggers intense precipitation—has provided only "a band-aid on a gaping wound," says Julien Emile-Geay, a paleoclimatologist at the University of Southern California.

In fact, restoring the state's water supplies to their pre-drought levels would require several years of intense rain and snowfall