Flooding

Heavy rain can overwhelm drainage systems and flood streets and buildings. High tides and elevated coastal water levels can also flood low-lying waterfront areas, even without rain. Floodwater can be dangerous during and after a flood.

El Niño and coastal flooding

Warmer seawater expands, and El Niño-related Kelvin waves can temporarily raise coastal water levels. High tides can then reach farther inland. Storm surge and large waves can make coastal flooding worse.

Check National Weather Service (NWS) forecasts and warnings for affected locations, timing and precautions. Visit sf.gov/storms for the City’s current El Niño guidance.

• Make an emergency plan and gather supplies.
• Plan for high tides. Check NWS coastal flood advisories, watches and warnings before traveling or parking along the waterfront. Review the locations and times in each alert, and plan a route that avoids flooded areas.
• Know where water may collect. Be aware of low-lying streets, underpasses and drainage channels. Review SFPUC’s storm flood-risk map for areas at risk during a major rainstorm. This map shows stormwater runoff risk, not flooding from the Bay or ocean.
• Protect property before water rises. Move vehicles out of flood-prone areas and elevate belongings, electronics, business inventory and household chemicals. Do this only when safe; never enter floodwater to move or retrieve property.
• Maintain your sewer lateral. Work with a plumber to inspect and maintain the pipe connecting your building to the City sewer. See SFPUC’s Rain Ready resources for more property-protection tips.
• Explore flood-protection assistance. SFPUC’s Floodwater Grant Program supports eligible properties that have experienced flooding from the public right-of-way or sewer-system backflow during heavy rain. Review the program’s requirements before applying.
• Review your flood insurance now. Most homeowners, renters and business insurance does not cover flood damage. Separate flood coverage is available. New National Flood Insurance Program policies generally have a 30-day waiting period. Learn about flood coverage and waiting-period exceptions.

Free sandbag pickup

San Francisco residents and businesses can get up to 10 free sandbags per address from Public Works, while supplies last. Bring proof that you live or operate a business in San Francisco.

Year-round pickup: Monday–Saturday, 8 a.m.–2 p.m., at the Public Works Operations Yard. Enter at Kansas and Marin streets. You will generally need to load your own sandbags, with limited exceptions.

Neighborhood Sandbag Saturdays: All pickups below run from 8 a.m. to 2 p.m.

• November 7: Marina Green Triangle, Marina Boulevard at Marina Green Drive.
• November 14: Sunset Circle Parking Lot, Sunset Boulevard at Lake Merced Boulevard.
• November 21: Marina Green Triangle, Marina Boulevard at Marina Green Drive; and Ocean Beach Parking Lot, Great Highway at Balboa Street, Stairwells 4–7.
• December 5: Sherman Street between Folsom and Harrison streets; and Fire Training Center, 19th and Folsom streets.

Check Public Works’ current sandbag information before you go. Sandbags are also sold at many hardware and home improvement stores.

• Turn around, don’t drown! Never walk, swim or drive through floodwater. Just six inches of moving water can knock you down, and one foot can sweep a vehicle away. Move to higher ground when it is safe to do so.
• Follow closures and evacuation instructions. Stay out of closed waterfront areas and never go around barricades. If officials tell you to evacuate, leave as directed.
• Stay away from downed power lines and flooded electrical equipment. Floodwater can hide electrical hazards, debris, sewage and chemicals.
• Report routine flooding problems to 311, including clogged catch basins, localized street flooding, sewer backups or wastewater odors. Use sf311.org, the 311 app or call 3-1-1.
• Call 9-1-1 for emergencies.

Storm and Flood Hazard Map

Explore our Storm and Flood Hazard Map for local flood-risk zones, PG&E outage areas, sandbag pickup locations and National Weather Service hazard information.

Select “Layers” (the icon that looks like a stack of papers) on the map to explore these resources.

For current sandbag pickup hours and neighborhood distributions, check Public Works’ sandbag information.

Visit our Storm and Flood Hazard Map

• Check on your neighbors, especially older adults and people with disabilities or medical conditions who may need help.
• Document damage when it is safe. Take photos and keep receipts and records of cleanup and repairs.
• Clean up safely. Wear protective clothing, rubber boots, gloves and eye protection. Floodwater may contain sewage, hazardous chemicals and sharp objects.
• If you come into contact with floodwater, wash exposed skin with soap and clean water. Wash contaminated clothing in hot water and detergent before wearing it again. If you have a puncture wound or contaminated injury, ask a health care professional whether you need a tetanus booster.
• Clean and disinfect hard surfaces. Wash with soap and clean water, then follow the cleaning product’s label and CDC’s instructions for safe disinfecting. Never mix bleach with other cleaners. Ventilate the area.
• Prevent mold growth. Dry out building interiors and remove wet items promptly. Use fans and dehumidifiers only when it is safe to use electricity. Follow CDC’s mold-cleanup guidance for protective equipment and safe cleanup.
• Keep food safe after flooding or a power outage.
  • Keep refrigerator and freezer doors closed. Food stays safe for up to 4 hours in a closed refrigerator, 48 hours in a full freezer or 24 hours in a half-full freezer.
  • After 4 hours without power, discard refrigerated perishables unless ice or another cold source has kept them at 40°F or colder. Never taste food to check whether it is safe.
  • Discard food that may have touched floodwater. See food-safety guidance for businesses for more information.
• Watch for chemical hazards from moved or spilled cleaning supplies, paint, pesticides, antifreeze or oil. Learn how to dispose of household hazardous waste.

For more information about what to do if backup or flooding occurs in your building, visit SFPUC’s Rain Ready resources.

• Review the City’s El Niño and severe-storm guidance.
• Check National Weather Service Bay Area forecasts and warnings.
• Read the National Weather Service’s flood safety tips.
• Find out how disasters and emergencies can affect San Francisco.
• Review the steps to get prepared for any emergency.

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