If you live in an area that's prone to flooding, you should always be prepared to take action in the event of the worst — which could even include being ready to evacuate. Jump to how to prepare your home for a storm.
What is an atmospheric river?
An atmospheric river is a kind of weather system that brings trillions of gallons of water vapor from the Pacific Ocean to California. Unlike several of the previous storms to hit the Bay Area, this latest storm landing on Monday night is not caused by an atmospheric river.
Beyond that, the NWS predicts that unsettled conditions will return starting Sunday and lasting into Monday.
In short: Don't assume this latest bout of rain will be the last.
How should I start preparing?
First up, understand just how much you — and your home — could be affected by another storm of this magnitude.
Previous storms in the Bay Area have knocked down trees, flooded roads and cut power to tens of thousands of homes and businesses, and contributed to several deaths. Winds have also previously forced the cancellation of flights at local airports including San Francisco International Airport.
Flooding could mean you have to evacuate your home, or live without crucial services for an extended period. Besides flashlights, experts recommend having an emergency supply kit ready in both your home and car — should you need to evacuate — that includes nonperishable foods, necessary medications, cleaning supplies and water for several days, in case services are cut off in your area. You can also include a copy of your ID, charging cables for your cellphone and a portable cellphone battery pack.
If your home experienced flooding during previous storms this year — or in storms from years past — officials recommend having sandbags, plastic sheeting and other flood control materials ready. Counties, public utilities and even community organizations across the Bay Area are distributing free sandbags. Keep in mind that some distribution sites, like those in San Francisco and San José, may ask you to show ID to prove you are a resident. Learn more about where to find sandbags.
Following the atmospheric river storm that hit Northern California on New Year's Eve, officials around the Bay Area have doubled down on efforts to keep waterways and storm drains clear to reduce the risk of flooding in residential areas. Both Oakland and San Francisco have programs where residents can “adopt” a storm drain in their community and help remove leaves and other debris.
FEMA also has created a tool that tracks which parts of a city are under flood risk — and to what extent. You can input your address in the FEMA Flood Map Service Center. Once the map tool locates your address, you can select the "Dynamic Map" option to see a more detailed map that may have certain neighborhoods or blocks color coded to represent flood risk.
If you are a homeowner, keep in mind that most home insurance plans do not cover damage caused by flooding. However, you can buy an additional policy with the National Flood Insurance Program through your existing insurance provider. It’s important to mention that if you decide to buy a plan now, there is a 30-day wait period for the benefits to begin, so the policy would not cover damages potentially caused by this week’s storms.
I need sandbags. Where can I get them?
In San Francisco, officials in the past have stressed that only residents who have previously experienced flooding in their homes should seek out the free sandbags provided by city agencies. Additionally, San Mateo County has added on its emergency preparation website that sandbags brought out during a previous storm can be reused.
If your home has flooded in the past and you’re looking to pick up free sandbags, several options are available. Be aware that some sites may offer bags and sand separately or exclusively, and that you may need to bring your own shovel to some locations. You may also be required to prove county residency with an ID. Be sure to research the site you're visiting before leaving.
City of Berkeley: Berkeley residents and businesses can get up to five sandbags with an ID or business card, from the City of Berkeley Corporation Yard (located on 1326 Allston Way, open 8 a.m.–4 p.m. Monday–Friday).
San Francisco: San Francisco is offering up to 10 sandbags per resident at their Operations Yard (located on the corner of Marin and Kansas, near Cesar Chavez). Although the site usually closes at 2 p.m., it will be open till 5 p.m. on Thursday, according to a tweet from the city's public works agency.
San Mateo County: San Mateo County offers a limit of 15 premade sandbags per resident, and says the county will also "provide materials for individuals to fill as many bags as they need on their own."
Flooding, downed trees and downed power lines: All of these can create the very real possibility of power outages during a storm like this.
Remember: It can sometimes take days for PG&E to do safety checks and turn your power back on, particularly if an outage affects a large enough number of people. If you have medical needs that rely on power, consider planning which family members or friends you can stay with during a lengthy power outage. You might also talk to your doctor in advance about how to prepare with medications or mobility needs.
Things to have close at hand before a potential power outage:
Battery-powered flashlights, ideally one for every household member.
A supply of fresh batteries.
Portable chargers or battery packs to keep your mobile phone charged.
LED candles, instead of wax candles, are recommended by PG&E.
A battery-powered radio to hear updates on storm conditions and outages.
Nonperishable food (think canned goods) and water: The state recommends having enough food and water for every member of your household for three days.
A thermometer to make sure your food is safe to eat (more on that below).
Make sure you know exactly where these crucial items are, so you're not scrambling to find them in the dark.
Other things to do ahead of an outage:
Fully charge your cellphone and any portable chargers.
Get cash, as ATMs may not work during a power outage.
Top your vehicle up with a full tank of gas (similarly, gas stations may not be operational during an outage).
Fill up plastic containers with water and store them in your freezer, which you can use later as ice substitutes to keep food fresh.
Additionally, make sure you and your household all know:
How to manually open any door in your home or building that requires electricity (think garage doors, apartment complex doors that require key cards).
How you'll communicate in an emergency situation, and not depend on a phone that needs electricity.
Once your power is out, be especially purposeful about when you open your freezer or your refrigerator.
A refrigerator that loses power can keep food cold for about four hours, and a freezer for about 48 hours, if kept closed. Plan to rely on coolers with ice or any water-filled plastic containers you've frozen ahead of time.
The state recommends that during an outage, you monitor food temperatures with a thermometer — and throw out any food that has a temperature of 40 degrees or higher.
If you're opting to use a camp stove or a grill in the absence of your oven or microwave, you should only use these appliances outdoors.
During these storms, officials urge residents to limit unnecessary travel and stay home if at all possible during weather events like these, citing the potential dangers presented by downed trees and power lines in addition to flooding.
If you must drive, use your headlights, turn off cruise control, maintain a firm grip on the steering wheel and drive more slowly and cautiously than usual. Leave twice as much space between your vehicle and the one in front of it; wet roads might mean it takes longer to stop. Be alert for debris on the road. If your car begins to hydroplane, do not slam on the brakes. Remain calm, ease off the gas, steer in the direction you want to go and very lightly pump the brakes until you regain traction.
If flooding occurs, err on the side of caution. Don’t assume you know the depth of a pool of water or the conditions of the road underneath it, especially at night.
Always turn around rather than driving through a flooded area — as few as 6 inches of water is enough to disable or stall a small car, while 12 inches can sweep away a vehicle. If floodwaters begin to rise around your car, abandon the car and move to higher ground on foot. According to the California Department of Water Resources, more people become trapped and die in their vehicles than anywhere else during a flood.
How can I receive updates about my area?
If you haven’t done so already, sign up to receive emergency weather alerts from your county. County officials use these notifications to inform residents of weather alerts, street and road closures, and evacuation orders. Find your county below:
In San Francisco, officials have asked the public to call 311 to report flooding inside homes, instead of 911. “We still have to run all our critical 911 calls whether it's a cardiac arrest, a car accident or a fire. If you add all these flooding issues ... it can really overtax the system,” Fire Chief Jeanine Nicholson said. “So if you have a little bit of flooding in your home, call 311. If someone is having a heart attack or if someone is being swept by water, call 911.”
An earlier version of this story was published on March 13. KQED's Daisy Nguyen and Erin Baldassari contributed to this story.
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