State water supply experts say it will also take more than one good year of heavy snow to begin recovery of the state's groundwater basins from several years of drought.

Communities, largely home to low-income Latino residents, still have dry wells. Restoring groundwater takes decades, with costly, long-term replenishment projects — and ultimately, much less pumping.

Despite some early season rain, the U.S. Drought Monitor classifies 99.48% of California as  being in drought. About 85% of the state, and all of Santa Clara County, are classified as being in a severe, extreme or exceptional drought, with reservoirs well below their historical averages for this time of year.