Active Alerts

If you are experiencing a water, power, or sewer emergency or service problem call our 24-hour hotline at 3-1-1 or (415) 701-2311 from outside SF or log on at sf311.org. Learn more or review active service alerts.

Flood Maps

Is your property at risk of flooding in a major rainstorm? Review our 100-Year Storm Flood Risk Map, learn about required property sale and rental disclosures, and take advantage of our resources to prepare for and minimize impacts of heavy rains on your property.

100-Year Storm Flood Risk Map

As San Francisco developed over time, its hilly topography, sand dunes, creeks, and wetlands have been largely developed. During extreme storms, stormwater runoff still flows along the naturally formed historical waterways. When this occurs, we can experience flooding that sometimes results in property damage, especially in low-lying areas of the City.

The San Francisco Public Utilities Commission (SFPUC) has developed a 100-Year Storm Flood Risk Map (Flood Map)—an informational tool that shows areas of San Francisco where significant flooding from stormwater runoff is highly likely to occur during a 100-year storm. A 100-year storm means a storm with a 1 percent probability of occurring at a particular location in a given year—meaning a very intense storm.  Despite this statistical likelihood, such intense storms can and do occur more frequently, sometimes within just a few years or each other or even within the same year. The SFPUC uses computer modeling that simulates flooding during a 100-year storm to identify areas that are likely to experience flooding in a 1 percent chance storm.

The purpose of the Flood Map is to inform existing and future property owners and tenants about flood risk on their properties so that they can take steps to protect their properties and belongings.

The Flood Map shows parcels that are highly likely to experience deep and contiguous flooding during a 100-year storm. Deep and contiguous flooding means flooding that is at least 6 inches deep, spanning an area at least the size of half an average city block.

The Flood Map, updated in December 2024, now shows the flood elevations for these areas in San Francisco, by flood elevation zones. A flood elevation is the height (rounded to the nearest foot) above the San Francisco City Datum that stormwater flooding is likely to reach during a 100-year storm. A flood elevation zone is an area which has the same flood elevation.  A datum is a coordinate system with a defined reference surface (such as sea level) used to represent the position of locations with known heights either above or below that reference surface. Flood elevations do not represent the depth of flooding above existing ground level. For more information, please review our Information Sheet, which contains Frequently Asked Questions and answers.

San Francisco law requires sellers or landlords of property in San Francisco to disclose to buyers or tenants if the property is within the 100-year storm flood risk zone shown on the SFPUC’s Flood Map. Flood elevations are not required in the disclosure but are provided to further inform actions that owners and tenants may wish to take to protect their properties against flooding and minimize potential impacts.

The Flood Map shows flood risk from stormwater runoff only. It does not show flood risk from other causes, such as water coming in from San Francisco Bay, the Pacific Ocean, or lakes; the depth of flooding from the ground surface level (for example, the depth of flooding from the street surface level); or the historical record of flooding at a given location. Read our full Flood Map Disclaimer.

If you have question or want to learn more about the Flood Map and other efforts to increase flood resilience in San Francisco, please review our Information Sheet or contact us at RainReadySF@sfwater.org.

Is your property in the 100-Year Storm Flood Risk Zone? To find out, please click on the searchable map below and enter your address. If you want a hard copy of the Flood Map, please contact us at RainReadySF@sfwater.org or (415) 554-3289. This map was updated in December 2024.

Screenshot of 100 Year Flood Map with elevation layers

 

Flood Resilience

The SFPUC has been working with other San Francisco City Departments, along with other groups such as private property owners, neighborhood organizations, and developers, to reduce flood risk. We make infrastructure investments (such as upgrading or installing sewer pipes, tunnels, and pump stations) and provide services (such as cleaning sewer pipes and storm drains and making sandbags available for pickup). The SFPUC also offers innovative programs that make grants available to owners for use in managing stormwater on their properties. Owners can use the grants to enhance the flood resilience of their properties by adding flood barriers, trench drains, backflow prevention, rain gardens or permeable pavement to soak up or reroute the stormwater. See the Floodwater Grant website listed below for full details on what projects are eligible for grant funding. The Flood Map is one of the tools SFPUC uses to inform property owners and tenants who are within the 100-Year Storm Flood Risk Zone (Flood Risk Zone), helping property owners learn about their risk and take informed action.

The SFPUC provides resources to assist San Francisco residents to prepare and better protect their properties and belongings from damage that may occur due to heavy rain. These include:

  • If you are a property owner whose home or business has been subject to flooding from the combined sewer system or public right-of-way as a result of heavy rains, apply for a Floodwater Grant. This grant can provide up to $100,000 to implement projects to reduce the possibility of flooding on your property.
  • Purchase flood insurance through the Federal Emergency Management Agency (FEMA) National Flood Insurance Program (NFIP).
  • Report issues such as flooding, clogged catch basins, sewer backups, and displaced manhole covers to San Francisco’s customer service online portal or by calling 3-1-1.
  • Help out by joining our Adopt a Drain and Rain Guardians programs.
  • Monitor the weather reports.
  • Elevate belongings in garages and any low-lying areas on your property.
  • Pick up sandbags from SF Public Works.

Learn more at sfpuc.gov/rainreadysf.

What if I believe my parcel has been mistakenly included in the Flood Risk Zone?

The SFPUC has established a parcel review process through which parcels will be assessed and, if justified, removed from the Flood Risk Zone shown on the Flood Map. Only a full parcel can be removed from or added to the map, not just a building or structure in the parcel. A parcel owner would undertake the process to remove the parcel from the Flood Risk Zone and be relieved of the associated disclosure requirement. If a parcel is removed from the Flood Risk Zone, it is no longer displayed on the map and the disclosure ordinance would not apply. However, the removal of a parcel from the Flood Risk Zone does not mean the property is no longer at risk of flooding.

Owners of parcels included in the Flood Risk Zone may request a review if one or both of the following parcel review rules and removal criteria apply:

  • Parcel’s ground elevation (not buildings or units) is entirely above the 100-year storm flood elevation.
  • Barriers (e.g., solid walls or solid fences) on the parcel reroute stormwater from the entire parcel so that no part is within the 100-year storm flood extent.

The process for reviewing and potentially removing a parcel from the Flood Risk Zone is as follows:

  • The property owner must first submit the Parcel Review Request Form to SFPUC.
  • SFPUC staff will then perform a preliminary review and do a site visit to the parcel to determine whether additional data are needed.
  • The parcel owner will need to accommodate and assist SFPUC in these review efforts by providing access to the parcel for site inspections and/or surveys.
  • Once all necessary site assessments are completed, SFPUC will determine whether one or more of the removal criteria are satisfied.
  • SFPUC will send the parcel owner a written notice of its parcel determination.
  • The map will be updated on an annual basis to incorporate and reflect all property review determinations that have been made.

Please read our full Removal Criteria to better understand the process.

If you have any questions about the Flood Map or flood resiliency in general, please contact us at RainReadySF@sfwater.org or (415) 554-3289.

More Information 

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