California’s Beaches Are Showing Remarkable Stability and Even Gaining Width According to New Long-Term Studies

California’s coastline has long been a symbol of natural beauty, recreation, and coastal living, but it’s also a region where concerns about erosion and rising sea levels often dominate public discussion. Two new pieces of research from UC San Diego’s Scripps Institution of Oceanography offer a surprisingly encouraging update: California’s beaches are not only holding steady, but many have actually gained width in recent years. These findings are based on both a detailed local study in San Diego County and a statewide analysis spanning nearly four decades.

What makes this especially interesting is that the results challenge the widely accepted narrative that California’s beaches are eroding in a steady, irreversible decline. Instead, the data shows a coastline that is much more dynamic — and more resilient — than we might expect.

San Diego County Beaches Show Widening After the Latest El Niño

The 2025 San Diego County Beach Report, part of a long-running monitoring program by the Scripps Coastal Processes Group, found that most beaches across nine key sites in the county actually expanded in width between October 1, 2024, and September 30, 2025. The monitored beaches include:

• Carlsbad State Beach
• South Carlsbad State Beach
• Leucadia State Beach
• Moonlight State Beach
• San Elijo State Beach
• Cardiff State Beach
• Torrey Pines State Beach
• Silver Strand State Beach
• Border Field State Park

Some of these beaches have been surveyed continuously for over 20 years, giving scientists long-term insight into how they evolve.

To collect data, researchers use LiDAR technology — high-frequency laser scanning — mounted on trucks, ATVs, drones, and sometimes even jetskis. These tools produce precise 3D maps that show exactly where sand has accumulated or eroded over time.

Last year’s growth is attributed to a post-El Niño recovery phase. During El Niño years, California typically faces stronger waves that pull sand offshore, narrowing beaches. The calmer years between these events usually allow beaches to rebuild. According to the new observations, the region is officially in a recovery phase, and this widening may continue for several years.

However, researchers caution that recovery cycles can be interrupted. The expected recovery phase between the 2016 and 2024 El Niño events was largely unsuccessful because multiple winters during that period produced unusually strong waves — including the atmospheric rivers of 2022–2023 and an intense wave event in 2021. As a result, many beaches actually continued to shrink despite not being influenced by El Niño at the time.

A notable part of the recent widening comes from beach nourishment projects in Encinitas and Solana Beach, where sand was added to the shoreline. This sand has since begun migrating south, contributing to the broader increase in local beach width.

Researchers also report that there is currently no clear trend linking local erosion patterns in San Diego to the ongoing rise in global temperatures. They note, however, that this could emerge with longer and more consistent historical data.

Statewide Satellite Study Shows Nearly 40 Years of Stability

The second study, published in Nature Communications, offers a high-level view of California’s entire sandy coastline from 1985 to 2021. What makes this study unique is that it used satellite imagery, specifically from NASA and the USGS Landsat program, analyzed through a toolkit called CoastSat. This software tracks shoreline position — the boundary where dry sand meets the ocean — across time.

The conclusion surprised even the scientists: despite significant erosion hotspots and decreased sediment flow from dammed or diverted rivers, the average width of California’s beaches has stayed remarkably stable over nearly four decades.

Some beaches have eroded significantly, while others have gained sand, leading to a statewide balancing effect. The researchers describe this as a reshuffling of the coastal “deck,” where sand may be shifting to new locations rather than disappearing entirely.

Examples of beaches gaining width (“winners”):

• Southern end of Camp Pendleton
• Venice Beach in Los Angeles
• Northern end of Ocean Beach in San Francisco

Examples of beaches losing width (“losers”):

• Oceanside
• San Clemente

Even after strong El Niño events — which often cause intense erosion — jet ski surveys off San Diego indicate that much of the sand has not left the system entirely. Instead, it may be temporarily stored offshore, sometimes as far as a quarter mile away, only to return over the next few years when conditions are favorable.

These findings suggest that although erosion is real and can be severe in specific locations, California’s overall beach system has displayed more natural resilience than expected.

Why This Matters for Coastal Communities

Beaches are more than just scenic landscapes. They are:

• Natural barriers against coastal flooding
• Economic engines for tourism
• Cultural and recreational hubs
• Ecological habitats

Understanding how they change is essential for future coastal planning. State Parks managers, for example, use the San Diego Beach Report to decide when and where to pursue nourishment projects or other interventions.

The studies also emphasize the importance of looking at beaches over multiple years, especially because short-term cycles (like post-El Niño recoveries) can mask or exaggerate long-term trends.

Extra Context: How LiDAR and Satellite Tools Help Track Beaches

Surprisingly, tracking a beach’s width is more complex than it sounds. Waves, tides, sandbars, storms, and human activity can all affect the shoreline.

How LiDAR works

• Fires thousands of laser pulses per second
• Measures the time they take to return
• Produces high-resolution 3D maps
• Detects subtle changes in sand height and slope

LiDAR is excellent for local, detailed measurements — perfect for beaches like those in San Diego County.

How CoastSat works

• Uses satellite imagery
• Identifies the boundary between sea and dry sand
• Tracks long-term shoreline movement
• Handles large-scale coastline analysis

This tool made it possible to analyze decades of beach movement across hundreds of miles of shoreline.

Together, these tools complement each other, offering both the fine detail and the big picture.

Extra Context: How El Niño Shapes California’s Beaches

El Niño is a periodic warming of the Pacific Ocean that affects global weather patterns. In California, El Niño years usually bring:

• Larger, more powerful winter waves
• Intense coastal erosion
• Storm-driven sand removal
• Disruption of natural sand recovery cycles

During El Niño winters, sand is often dragged offshore into deeper water. Recovery happens later when smaller waves gradually push the sand back. But recovery isn’t guaranteed — if extreme weather events occur in non-El Niño years, they can interrupt the rebuilding process.

This makes long-term data crucial. A single snapshot can misrepresent the natural cycles.

The Big Takeaway

Taken together, these two studies offer one of the most comprehensive looks at California’s beaches to date. They show a coastline that is dynamic, variable, and more resilient than many expected, even in the face of climate-related concerns.

However, stability on average does not mean every beach is safe. Some regions continue to face severe erosion, and future sea-level rise may introduce challenges that aren’t yet apparent in the data. Still, the new findings give coastal managers a clearer understanding of how California’s beaches behave — and how they may continue to evolve.

Research Reference:
Interannual wave-driven shoreline change on the California coast (Nature Communications)