Major renovations begin on Anderson Dam tunnel project; reservoir can't be used for 10 years

Major renovations will begin Wednesday on the Anderson Dam tunnel project in Santa Clara County. 

The project will require the reservoir to be drained – and it will be unable to be used for 10 years.

The timing is not great as California remains in a drought but water officials say this is a vital project for flood protection that will protect the public for years to come.

The reservoir, which can hold 90,000 acre-feet, is the water district’s largest drinking water reservoir.

The project is expected to take three years: Crews will build a larger outlet tunnel next to the dam which will allow the release of more water during a storm or other emergency.

After the tunnel project is completed a large seismic retrofit project will take place to strengthen the dam in case of a large earthquake. That is estimated to take seven years.

Officials met back in May to discuss the project and the impact during construction.

"The tunnel project will take approximately two and a half years and several more years for the full project," Santa Clara Valley Water District Director John Verela said back then. "We understand this will be a long endeavor and will do our best to minimize any impacts to the neighborhoods. As we move forward."

Even though Santa Clara County is going through a drought emergency and residents are being asked to cut back on water use, officials say this work is necessary and as the state faces more drought years in the future.