San Francisco Hazard Maps: Liquefaction, Flood and Sea-Level Rise
San Francisco buyers should check four official hazard maps for any address: the California Geological Survey’s Seismic Hazard Zones for liquefaction and earthquake-induced landslides, FEMA’s flood insurance rate map, the SFPUC’s 100-Year Storm Flood Risk Map, and the city’s sea-level-rise planning maps for the shoreline. Each shows a different risk, so a property can be on one map and not the others. Two of them carry disclosure duties when a home sells: the state Natural Hazard Disclosure covers seismic hazard zones and FEMA’s high-risk flood zones, and the city’s Police Code Article 51 covers the SFPUC storm map.
The ground under San Francisco varies block by block, from bedrock hills to bay fill and dune sand, so neighborhood names are a poor guide to risk. This page explains what each map shows, what we found when we checked sample points across the city, how the maps relate to building risk such as soft-story apartments, and the order in which to check a specific address. For the city overview, start with our San Francisco real estate guide.
The four maps at a glance
| Map | What it shows | Who publishes it | At sale |
|---|---|---|---|
| Seismic Hazard Zones (liquefaction and landslide) | Areas where ground conditions could liquefy or slide in a strong earthquake | California Geological Survey; shown on SF Planning’s maps | Disclosed on the Natural Hazard Disclosure Statement |
| FEMA Flood Insurance Rate Map | Coastal flooding from the Bay and ocean; map in effect since March 23, 2021 | FEMA | Zone A or V is disclosed on the Natural Hazard Disclosure Statement |
| 100-Year Storm Flood Risk Map | Deep, contiguous stormwater flooding from a 100-year rainstorm | San Francisco Public Utilities Commission | Written disclosure required under Police Code Article 51 |
| Sea-level-rise maps | Shoreline areas exposed to higher tides and future flooding | Port of San Francisco, SF Planning and partners | No specific city disclosure form; ask and check |
Liquefaction and landslide zones
Liquefaction happens when loose, water-saturated soil loses strength during shaking and behaves like a liquid. The California Geological Survey’s Note 53 says liquefaction damaged the Marina District in the 1989 Loma Prieta earthquake, and that the 1906 earthquake set off more than 10,000 landslides across the region.
Inside a mapped Seismic Hazard Zone, the CGS says cities and counties must withhold building permits until a geologic or geotechnical investigation is done, and must require design or ground-improvement measures if the hazard is confirmed. SF Planning’s version of the liquefaction layer flags certain projects for that review, such as new building construction and some additions. Sellers must check the state maps and report the result on the Natural Hazard Disclosure Statement.
What we found at sample points
We queried SF Planning’s map service, which carries the CGS liquefaction and landslide zones, at street corners across the city in October 2026. These are point checks, not parcel determinations, so check the exact address yourself.
| Location checked | Liquefaction zone? | Context |
|---|---|---|
| Chestnut and Fillmore streets, Marina | Inside | The district CGS cites for 1989 liquefaction damage |
| Central Mission Bay | Inside | Part of one large mapped zone along the former bay margin |
| 7th and Folsom streets, South of Market | Inside | Same large zone |
| Front and Clay streets, Financial District | Inside | Same large zone |
| Valencia and 18th streets, Mission District | Inside | Same large zone |
| Third and Evans, Bayview near Islais Creek | Inside | The Port says Islais Creek was creek and marsh filled in the late 1800s |
| Treasure Island, interior | Inside | Mapped zone covers the island point we checked |
| Hayes and Laguna streets, Hayes Valley | Outside | No liquefaction polygon at this point |
| 46th Avenue and Judah Street, Outer Sunset | Outside | No liquefaction polygon at this point |
Landslide zones follow steep ground instead. A box about half a mile across centered on Twin Peaks returned 21 separate landslide-zone polygons (our Twin Peaks page, using a box drawn around that neighborhood’s parcels, counts 17), and a small box on the east side of Telegraph Hill returned two. On a hillside lot, ask for any geotechnical reports, retaining-wall permits and drainage history.
How to read a zone result
A zone is a trigger for investigation, not a verdict on a building. A well-engineered building inside a zone can perform well, and a weak building outside one can perform badly.
For an existing home, the zone mainly affects what a buyer should ask for: the foundation type, any soils report, retrofit permits, and how any future addition would be reviewed. The state’s Natural Hazard Disclosure form also reports earthquake fault zones; use the CGS EQ Zapp viewer to see whether any apply to an address, and our guide to earthquake fault zones in California explains what they mean.
FEMA flood zones in San Francisco
FEMA’s map for San Francisco has been in effect since March 23, 2021, and SF Planning carries it as a layer. It maps flooding from open water, the Bay and the ocean, not rainstorms. Our point checks show how narrow the high-risk zones can be:
- On the beach at Ocean Beach, west of the Great Highway at Judah, the map shows Zone VE, a high-risk coastal zone with wave action, with a base flood elevation of 21 feet.
- In central Mission Bay, the map shows shaded Zone X, a moderate-risk area outside the special flood hazard area.
- At the interior Treasure Island point, it shows unshaded Zone X.
Only Zone A and Zone V areas count as a special flood hazard area on the state Natural Hazard Disclosure form. If a parcel touches one, ask your lender early whether flood insurance will be required, and get a quote before your contingencies run out.
The SFPUC 100-Year Storm Flood Risk Map
This map answers a different question: where heavy rain overwhelms the sewer and drainage system. The SFPUC’s December 2024 FAQ defines the risk zone as parcels likely to see flooding at least 6 inches deep across an area at least half an average city block during a 100-year storm. About 2,100 parcels, roughly 1% of the city, are in the zone, and about half are residential.
- What it leaves out: flooding from the Bay, the ocean or lakes, and sea-level rise. Parcels outside the zone can still flood.
- Elevations: since December 2024 the map shows flood elevations in feet above San Francisco City Datum, based on a 2010 ground model. They are not depths above the street.
- Updates: the SFPUC updates the map every year to reflect parcel reviews.
- Removal: a whole parcel can come off the map if its ground is entirely above the flood elevation, or if walls or solid fences keep the flood extent off it. The SFPUC cautions that removal doesn’t mean the property can’t flood.
- Help: owners whose home or business has flooded from the sewer system or the street can apply to the Floodwater Grant Program, which the SFPUC says can provide up to $100,000. The FAQ lists (415) 554-3289 as the SFPUC contact line.
Article 51 disclosure
Since 2019, San Francisco Police Code Article 51 has required a seller of property in the flood risk zone to give a specific written disclosure before the sale contract is signed or title transfers. Landlords must give it before a lease is signed.
The SFPUC notes that the law does not require disclosure of the flood elevations themselves. Our San Francisco selling requirements checklist shows where this fits with the city’s other point-of-sale rules.
Sea-level rise along the shoreline
Sea-level rise is a planning map, not a disclosure map, but it matters for anyone buying near the waterfront for the long term. The Port of San Francisco’s Waterfront Resilience Program covers its 7.5-mile jurisdiction from Aquatic Park to Heron’s Head Park and plans for 3 to 7 feet of sea-level rise by 2100.
The U.S. Army Corps of Engineers and the city have released a Draft Plan for coastal flood defenses along that shoreline. The Port also notes that areas filled in the 1800s, such as Islais Creek, face liquefaction as well as flooding.
The citywide San Francisco Shoreline Adaptation Plan began in 2026, with a draft due for public review and adoption in 2028. Its June 2026 information sheet says that without action, more than 10% of the city could face regular flooding later this century, and that record high tides in January 2026 flooded roadways along the Embarcadero.
On the ocean side, SF Planning’s Coastal Zone layer includes the Great Highway at Judah but not 46th Avenue at Judah, so blocks only a few hundred feet apart fall under different permit rules. Inside the Coastal Zone, development follows the city’s coastal rules in the Planning Code.
Building risk: soft-story apartments and the ground under them
Hazard maps describe the ground; the building matters as much. San Francisco’s Mandatory Soft Story Retrofit Program, created in 2013 and enforced by the Department of Building Inspection, covers wood-frame buildings of three or more stories, or two stories over a basement or underfloor area, with five or more units, where the construction permit was applied for before January 1, 1978. DBI says these buildings are most common in the Mission, Western Addition, Richmond, North Beach and Marina districts.
That list overlaps with the liquefaction zones above in the Marina and the Mission. For a building in both, ask for the retrofit permit and engineer’s plans, and check DBI’s soft-story property list.
DBI also notes that seismic strengthening may qualify for exclusion from property tax reassessment if the owner files the exclusion form within 30 days of completing the work. Our guide to seismic retrofits for multifamily buildings covers the investor side.
How to check a San Francisco address
- Seismic zones: enter the address in the California Geological Survey’s EQ Zapp viewer, or open SF Planning’s Property Information Map and look at the hazard layers.
- FEMA flood zone: look up the parcel on FEMA’s Flood Map Service Center or SF Planning’s FEMA layer, and note the zone and panel.
- Storm flooding: check the SFPUC 100-Year Storm Flood Risk Map, and ask the seller for the Article 51 disclosure if the parcel is in the zone.
- Shoreline exposure: near the Bay or Ocean Beach, review the Port’s and the Shoreline Plan’s maps for the blocks around the property.
- The disclosure report: read the Natural Hazard Disclosure report closely; our Natural Hazard Disclosure guide explains each line.
- The building record: pull DBI permit history, any soft-story compliance, and any geotechnical or foundation reports the seller has.
- Insurance: get earthquake and, where relevant, flood insurance quotes during your inspection period.
Selling a home with a mapped hazard
A mapped hazard rarely stops a sale in San Francisco, but late surprises do. Order the Natural Hazard Disclosure report early, prepare the Article 51 disclosure if the SFPUC map applies, and gather the documents a buyer will ask for: retrofit permits and sign-offs, any soils or foundation reports, flood history and any backflow or drainage work. These records matter to buyers because they bear on insurance, lending and future permits.
This is general information, not legal advice; talk to a California real estate attorney about disclosure questions, or a geotechnical engineer about ground conditions at a specific site.
Questions people ask
Where are the liquefaction zones in San Francisco?
Mainly on filled land and former marsh along the Bay and in some valleys. In our checks, points in the Marina, Mission Bay, South of Market, the Financial District, the Mission near Valencia and 18th, Bayview near Islais Creek and Treasure Island were inside a mapped zone; points at Hayes and Laguna and at 46th Avenue and Judah were not. Check each address.
Does being in a liquefaction zone mean I can’t get a loan or insurance?
Not by itself. The zone’s legal effect is that new construction and some additions need a geotechnical investigation and that the seller must disclose it. Ask your lender and earthquake insurer how they treat the building itself.
What is the difference between the FEMA flood map and the SFPUC flood map?
FEMA maps flooding from the Bay and ocean. The SFPUC map shows stormwater flooding from a 100-year rainstorm and leaves out Bay, ocean and sea-level-rise flooding. A parcel can be on one and not the other.
Do sellers have to disclose the SFPUC flood map?
Yes, if the parcel is in the 100-Year Storm Flood Risk Zone. Police Code Article 51 requires a written disclosure before the contract is signed or title transfers. Landlords must disclose before signing a lease.
Is Mission Bay in a flood zone?
At the point we checked in central Mission Bay, FEMA’s map shows shaded Zone X, a moderate-risk area outside the special flood hazard area, and the same point is inside a liquefaction zone. Shoreline edges can map differently, so check the parcel.
Is Ocean Beach in a flood zone?
The beach itself is mapped as FEMA Zone VE with a base flood elevation of 21 feet at the point we checked west of the Great Highway at Judah. Blocks inland are mapped separately, so check the specific parcel.
What sea-level rise is San Francisco planning for?
The Port’s Waterfront Resilience Program plans for 3 to 7 feet of sea-level rise by 2100 along its 7.5 miles of shoreline from Aquatic Park to Heron’s Head Park.
Can a property be removed from the SFPUC flood map?
Yes, through the SFPUC’s parcel review, if the whole parcel is above the flood elevation or barriers keep the flood extent off it. The SFPUC says the disclosure ordinance then no longer applies to that parcel, though removal doesn’t mean it can’t flood.
Comparing neighborhoods or buildings and want help reading the maps for specific addresses? See how we work with San Francisco home buyers; we’ll pull the hazard layers and disclosure reports for the homes on your list.
Sources & notes
- California Geological Survey: Note 53, San Francisco Bay Area regulatory earthquake hazard zones (January 2023)
- San Francisco Planning: PlanningData map service, Seismic Hazard Zones (liquefaction and landslide), FEMA flood map and Coastal Zone layers (queried October 2026)
- San Francisco Public Utilities Commission: 100-Year Storm Flood Risk Map information sheet and FAQs (December 2024)
- Port of San Francisco: Waterfront Resilience Program
- Port of San Francisco: Islais Creek / Bayview Resilience
- San Francisco Planning: San Francisco Shoreline Adaptation Plan information sheet (June 2026)
- San Francisco Department of Building Inspection: Mandatory Soft Story Retrofit Program
- California Public Law: Civil Code section 1103.2, Natural Hazard Disclosure Statement
Last reviewed October 2026 by Matthew Martinez.
