SAN JOSE (KCBS)— With California in its fourth year of a record drought, getting too much rain may be the last thing on most peoples’ minds, but a new report finds a so-called 150-year “superstorm” could cause billions of dollars in damage, arguing that we’re unprepared.

The storm that hit Northern California last December made the national news, toppled trees, caused flooding, and was to blame for widespread power outages. However, that storm is barely a breeze compared to the superstorm predicted to occur about every 150 years or so. New York’s Hurricane Sandy in 2012 was considered a superstorm.

The nonprofit Bay Area Council released the report, “Surviving The Storm”, on Monday that says the storm could cause $10 billion in damage and bring 12 inches of rain in a week. The amount of damage would be about the same as the Loma Prieta Earthquake of 1989.

The report calls for several infrastructural improvements including sea walls, levees and better planning by local governments.

Much of Silicon Valley is below sea level and many of its big employers; Facebook, Google SFO International Airport are right along the water. The report paints a picture of flooded neighborhoods in San Mateo and Santa Clara Counties, as well as freeways and expressways underwater.

“We’re concerned that businesses won’t be resilient. Their services will be cut off in a major storm like this,” said Adrian Covert, the policy director for the Bay Area Council’s Economic Institute.

The report does not take into account the expected sea-level rise, which could magnify the estimated damage.

The council has suggested, and all three mayors of San Francisco, Oakland, San Jose, have agreed to a plan of coming up with $1 billion to shore up flood protections.

Covert said what’s even scarier is that they haven’t even looked at what would happen if a storm pushed through the Bay Area, destroying the Central Valley levee system and the drinking-water supply.

The council is a business-sponsored public policy advocacy organization, which includes dozens of prominent Bay Area figures and on its board of directors including 49ers President and CEO Jed York and Golden State Warriors President and COO Rick Welts.

The council has created a website dedicated to preparing in the event of a 150-year storm. More than 275 of the largest employers in the Bay Area support the Bay Area Council, according to its website.