Thanks in part to a wet December that brought heavy snow to the Sierras, 2020 is off to a good start with reservoir storage levels at or above historic averages throughout most of the state – good news for San Bernardino Valley residents. Even though water districts and cities throughout the San Bernardino Valley rely on local rainfall and mountain runoff for about 70 percent of their water supply, local supplies are not enough. The region relies on Sierra snowmelt from Northern California to meet the remaining 30 percent.