Water levels at the San Luis Reservoir in the Central Valley is at a near-record low.
The low 17-percent water level is due to a dry couple of years coupled with regulatory restrictions preventing operators from importing more water from the Delta to save wildlife, officials said.
"It's a continuing concern every year," said Cindy Kao of the Santa Clara Valley Water District. "Every year we worry about the low point at San Luis Reservoir."
The Silicon Valley gets its water supply from three different sources: Its own reservoirs, the South Bay Aqueduct from the Delta and the San Luis Reservoir.
Low levels at the San Luis Reservoir is a concern for Santa Clara County.
"If this winter is dry, next year we can potentially see lower levels at the reservoir," Kao said.
Another dry year and the water district might have to call for water rationing.
"It's always on the table," Kao said.
View more in Damian Trujillo's video report above.