The clock is ticking for the Santa Clara Valley Water District to get the Anderson Reservoir dam seismically safe.
Experts say the dam in Morgan Hill is not seismically safe, and it would only take a 6.6-magnitude earthquake to make the dam crumble.
The reservoir holds 29 billion gallons of water -- more water than all the other reservoirs in the district combined. Morgan HIll and parts of San Jose could potentially end up underwater if the reservoir's aging dam falters in a strong earthquake.
"It could be devastating, a huge catastrophe," Santa Clara Valley Water District spokesman Marty Grimes said.
Federal and state regulators have set a deadline to get the dam seismically safe by 2018. The Santa Clara Valley Water District has until the end of this year to get the $123 million project underway.
In order to get the project started, the agency will have to empty the reservoir
"The timing is difficult," Grimes said. "We're obviously in a drought right now and we don't have to make that decision today."
Morgan Hill resident Cecilia Logan lives in the shadow of the Anderson Reservoir dam. She said it's counter-intuitive to empty the reservoir in the middle of a drought.
"We're asked to conserve water, I conserve water," Logan said. "But then water's just disappearing."
Experts said the chances of the dam failing are slim.
Officials also are keeping the water level at the reservoir low in case of an earthquake.
A decision on when to start draining the reservoir is expected to be made in the coming months.