Winter 2026-2027 El Niño Preparedness
This winter, El Niño, king tides, and storms could raise Bay Area water levels 3 to 4 feet above normal. Check your flood risk, learn how to prepare, and read about BCDC’s permitting approach.
Property on the shoreline?
Read how BCDC is modifying its permitting approach for the El Niño season. Temporary flood barriers must come down by April 30, 2027.
Why this winter could be different
A stronger El Niño this winter
El Niño is a natural climate pattern that occurs when waters in the tropical Pacific Ocean become warmer than usual. This warming changes ocean and wind patterns, affecting weather around the world. El Niño typically occurs every two to seven years and lasts about 9 to 12 months. Scientists expect this winter’s El Niño to be especially strong, with ocean temperatures forecast to be about 6.3°F above average.
How will it affect the Bay Area?
The main Bay Area risk is flooding from the ocean and Bay.
- Higher seas. Warm water expands, and warming from El Niño could raise sea levels along the California coast by up to 12 inches.
- Higher tides. King tides are the highest tides of the year and can raise sea levels by 12 inches.
- Storm surge. Winter storms can push water several feet higher.
- All three together. When El Niño, a King Tide, and a storm happen at once, Bay Area water levels could be 3 to 4 feet above normal.
What about rain? El Niño often means a rainier winter in southern California, but the Bay Area doesn’t always follow that pattern. In past El Niño years, the Bay Area has typically received average rain, and sometimes less than average. However, periodic heavy rainfall can cause flash floods, mudslides, or debris flows around creeks, rivers, or low streets.
Check your flood risk
Many low-lying parts of the shoreline are prone to flooding, and flooding could get worse this winter. We urge all Bay Area residents to find out whether their home, neighborhood, or daily commute is at risk. Flooding can come from both the Bay and from hillside watersheds, so make sure you are prepared for both.
Where could coastal flooding occur during El Niño?
The map below shows areas that could experience coastal flooding during El Niño tidal conditions if a five-year storm and a King Tide were to happen all at the same time. A five-year storm is a storm with a 20% chance of happening in any given year.
Learn more about Bay Area shoreline flood risk
For additional information on potential flood risk in the Bay, visit BCDC’s ART Bay Shoreline Flood Explorer. If you are at risk, use the steps in the section and talk to your landlord and local city or county office about what help is available to prepare for possible flooding.
How to prepare
If you rent
- Talk to your landlord about flood prevention.
- Ask your landlord to clear drains and gutters before winter storms.
If you’re on the road
- Never drive through floodwater. Turn around and find another route.
- Find backup routes, or leave extra travel time on stormy days.
If you own or manage property on the shoreline
- Clear drains and gutters.
- Check your property for places that could flood or be damaged by waves or erosion from the Bay, or from stormwater runoff.
- Read about BCDC’s permitting approach to protecting your property below before you install any barrier.
BCDC’s El Niño permitting approach (2026-2027)
Information for people who own or manage property on the shoreline.
Quick reference
|
What you want to do |
Permit needed? |
|
Hand-place sandbags or “quick dams” |
No* |
|
Remove trash or debris that does not belong on the shoreline or in the Bay |
No* |
|
Place large “bulk bags” or other barriers that need heavy equipment or special skills to install |
No* |
|
Emergency installation of rip-rap (rock walls), seawalls, or berms (raised piles of earth); repair or strengthen levees; add sand or pump water to limit damage |
Yes. BCDC emergency permit required. |
*check guidance below for additional information
IMPORTANT DATE
All temporary flood barriers must be removed by April 30, 2027. If you want to keep a barrier after that date, you must apply for a BCDC permit by April 30, 2027. Barriers without a permit that remain past that date may face enforcement action. The public may report a violation to our Enforcement team.
Sandbags and other temporary barriers
You do not need a BCDC permit to install hand-placed sandbags, “quick dams,”and other temporary flood barriers. More intensive temporary actions such as large sandbags (bulk bags) and other temporary flood barriers that require using heavy equipment or specialized knowledge to install also do not require a BCDC permit.
- However, placement of temporary barriers may not block public access. If this is not possible, temporary public access detours must be provided.
- Temporary barriers must not require engineering or ground disturbance and, when in place, must not pose a risk to natural resources in the Bay.
Debris Removal
Removal of debris or other items that clearly do not belong on the shoreline or in the Bay does not require a BCDC permit.
Large-scale emergency work
Larger-scale emergency actions include installing rip-rap, rock revetments, berms, seawalls, bolstering and/or repairing levees, or performing sand nourishment or pumping to limit damage pre-incident and/or repair damage post-incident. These require a BCDC emergency permit. These actions can harm Bay wildlife and habitat, so BCDC may add conditions to protect them and to track the work.
How do I get an emergency permit?
To fill out an application and for more information, visit our emergency permitting webpage BCDC can issue emergency permits within 24-48 hours of receiving a complete application.
An emergency permit may come with conditions. For example, the permit may expire once the emergency is over, and the permittee may then have to file a regular permit application if they want to keep what was authorized. BCDC may require changes to the work at that point so it complies with our laws and policies.