If you walked a North County beach this weekend, you may have noticed a lot of sand is simply gone. Tropical Storm Rachel’s remnants, a strengthening El Niño and some very high tides lined up at the same time, and the coast took the hit.
Here’s a quick, plain-English look at what’s driving it, how a beach can lose its sand in a matter of days, and what officials can do to bring it back.
Close to home in Carlsbad. Even before Rachel arrived, the City of Carlsbad declared a local emergency in September to fast-track work on an eroding coastal bluff along south Carlsbad Boulevard, ahead of the El Niño storm season. The plan is to extend existing rock protection at the base of the bluff to help protect the road above. Then this weekend, recent news reports showed Rachel’s surf stripping sand from North County beaches.
- El Niño is pushing coastal sea level up by several inches, so storms and high tides reach farther than usual.
- Storm waves don’t destroy sand. They drag it offshore onto sandbars, and some returns in calmer months.
- Officials can fast-track emergency permits, pump sand back from offshore and rebuild dunes, but restoration takes funding and time.
TrulySD · SD Life
Why San Diego’s beaches are shrinking
This weekend
Rachel’s remnants brought south and northwest swells, strong onshore winds and high tides over 7 feet. The National Weather Service warned that significant coastal flooding and beach erosion were likely.
What’s causing it
Higher water
El Niño sends slow ocean pulses called Kelvin waves up the coast, raising sea level about 6 inches, on top of long-term sea-level rise.
A very strong El Niño
Federal forecasters put the odds of a very strong event this fall and winter at more than 90%.
Storms on high tides
Damage peaks when big swell, strong winds and extreme high tides all hit at once.
Less sand to begin with
Dams trap sand rivers once carried to the coast, and seawalls hold back sand eroding bluffs once supplied.
How it happens
Beaches are always on the move
San Diego’s beaches are constantly changing. Powerful waves can move sand off the beach onto offshore sandbars, and calmer waves can bring some of it back. The timing varies from beach to beach. This fall, higher sea levels tied to El Niño and storm surf from Rachel added to the erosion.
Sand moves offshore
Powerful storm waves move sand from the beach onto offshore sandbars. In calmer conditions, some of it can return.
Water reaches farther
When the ocean runs higher and waves are stronger, water reaches farther up the beach, sometimes reaching roads and the base of the bluffs.
Cliffs lose their buffer
As the beach narrows, waves reach the cliffs more easily. How fast a cliff erodes also depends on its rock, wave energy, rainfall and groundwater.
Less sand, less protection
A wider beach absorbs wave energy before it reaches the cliffs. When the sand moves away, waves can strike the cliff base more directly.
How beaches can be restored
Fast-track permits
The governor’s Sept. 21 emergency directs the Coastal Commission to act on urgent emergency permits within 24 hours.
Pump sand back
SANDAG’s regional plan would dredge sand from offshore and place it on eroded beaches. It’s seeking funding, building on projects in 2001 and 2012.
Rebuild dunes
Restored dunes at Cardiff State Beach shield Highway 101, a nature-based model other cities are watching.
Make seawalls pay for sand
The Coastal Commission requires sand-mitigation fees for many San Diego seawalls, which go toward restoring local beaches.
What to expect
Expect more erosion this winter whenever storms line up with high tides.
What’s driving it
The biggest factor this fall is the ocean itself sitting higher than normal. El Niño sends slow, broad pulses of warm water called Kelvin waves along the equator and then up the West Coast. They don’t break like surf. Instead, NOAA Fisheries says they lift coastal sea level by roughly 6 inches, measurable at tide gauges. That’s on top of the long-term rise already underway.
This El Niño is a big one. The governor’s Sept. 21 emergency proclamation cites the National Weather Service Climate Prediction Center’s finding of a greater than 90% chance of a very strong event this fall and winter.
Higher water matters most when it stacks up with everything else. Ahead of Rachel, the National Weather Service pointed to the combination of south and northwest swells, onshore winds and morning tides over 7 feet. That’s the recipe for flooding and erosion.
Underneath it all, Southern California beaches start the season short on sand. A California State Assembly briefing notes that dams built for flood control trap sediment that rivers once delivered to the coast. The California Coastal Commission has long treated seawalls as a sand-supply issue too, since they hold back bluffs that would otherwise erode and feed the beach.
How a beach loses its sand in days
Sand doesn’t disappear into thin air. Scripps Institution of Oceanography at UC San Diego has documented the pattern: high, steep winter waves move sand from near the waterline to an offshore sandbar, narrowing the beach. Gentler summer swell pushes it back up. USGS research shows the timing varies, though, and many Southern California beaches are actually narrowest in spring or summer. A big storm like Rachel can move a lot of sand in a single high-tide weekend.
Bluffs feel it next. The USGS says sea-cliff erosion depends on sea level, wave energy, coastal slope, beach width and height, and rock strength. A wide, high beach soaks up wave energy before it reaches the cliff. When that buffer is gone, waves work directly on the base of the bluff.
A wide beach is the bluff’s first line of defense. When the sand goes, the cliff takes the hit.
How beaches can be restored
Faster permits. Under the governor’s emergency proclamation, the Coastal Commission must flag missing items in an application within five days and act on urgent emergency permit requests within 24 hours.
Putting sand back. SANDAG’s third Regional Beach Sand Project would dredge beach-quality sand from offshore and place it on the region’s most eroded beaches. As of early 2026, SANDAG says it is seeking federal and state funding for the next phase. Its earlier projects placed 2.2 million cubic yards of sand on 12 beaches in 2001 and 1.5 million cubic yards in 2012. In Encinitas and Solana Beach, a long-term federal sand project with the U.S. Army Corps of Engineers completed its first round in May 2024.
Rebuilding dunes. At Cardiff State Beach, a half-mile of restored dunes sits over buried rock to protect Highway 101. The City of Encinitas says the January 2024 storms again showed it working, and NOAA describes it as protection expected to last until about 2050.
Making seawalls pay for sand. When the Coastal Commission approves many San Diego seawalls, it requires an in-lieu sand fee that goes toward restoring the region’s beaches.
None of this is quick or cheap, and none of it stops the ocean. But together, these tools are how San Diego keeps its beaches as the water keeps rising.
What to expect this winter
With a very strong El Niño still building, expect more erosion whenever storms line up with high tides. Before heading out, check National Weather Service San Diego for coastal flood and beach hazard alerts, give bluffs plenty of room and avoid the beach below them at high tide.
For more on Rachel, see what San Diego should know about Tropical Storm Rachel and our look at San Diego’s tropical storm history, from the 1858 hurricane to Rachel.
- National Weather Service San Diego, Post-Tropical Cyclone Rachel local statement, Oct. 10, 2026
- Office of the Governor, El Niño state of emergency proclamation, Sept. 21, 2026
- NOAA Fisheries, ocean indicators for El Niño’s arrival on the West Coast
- California State Assembly, Beach Erosion and Declining Sand Supplies briefing
- California Coastal Commission, Mitigation of Impacts to Sand Supply
- USGS, Sea level rise could double erosion rates of Southern California coastal cliffs
- Scripps Institution of Oceanography, UC San Diego, beach width and seasonal sand movement
- City of Carlsbad, Local emergency to expedite proactive bluff stabilization
- USGS, Shoreline seasonality of California’s beaches
- SANDAG, Beach Sand Management
- City of Encinitas, Storm Damage Reduction Project
- City of Encinitas, Cardiff State Beach Living Shoreline Project
- NOAA Digital Coast, Cardiff State Beach dune restoration
