Why are we losing our Beaches?

Across the California coast and around the world, coastal erosion is eating at our beaches. For thousands of years, our beaches have stayed relatively the same. A natural process, longshore drift, moves and deposits sand along beaches, replenishing sand. Now, due to both human intervention and natural processes, our beaches are eroding into the ocean. Let’s understand what is the natural process of longshore currents, why this is happening to our beaches, and what we can do to keep them healthy. Let’s start the conversation!

Posted By Annika Furman on Sep 24, 2025

Lot (of) People: Episode 3 Reading Why are we losing our Beaches? 6 minutes

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What is a longshore current?

Have you ever been surfing, only to find that you’ve drifted far down the beach from where you started? This phenomenon is most likely due to longshore current, also known as “littoral drift.” When waves hit the beach at an angle, they create a current that moves parallel to the shoreline. This longshore current not only transports water (and sometimes you) but also carries sediments, a process referred to as longshore drift.

Longshore drift can have the ability to bend and change the shape of our coastline over time. This happens through the transportation of sand and sediment down our coastlines and beaches. Sand is transported alongshore by currents formed when waves strike the beach at an angle and then recede down the coastline. Sand is carried along the shore in a zigzag pattern following the current as it continues down the coast. Without intervention, longshore drift is a natural and healthy process; however, as humans continue to build on and disrupt our coastlines, the movement of sediment, or lack thereof, contributes to coastal erosion.

Why is our coast eroding?

Coastal erosion is a significant concern as we witness beaches disappearing and infrastructure like parking lots and bike paths crumbling into the sea. Trees, native plants, and sand dunes do a great job at protecting and buffering the beaches, but humans have built on top of dunes and removed native plants, causing the beach and sediment to erode quickly.

Our beaches have stayed relatively the same for the past 6,000 years; therefore, we thought our beaches were more stable than they are, and we built houses, roads, and other infrastructure along the coastline, on top of sand dunes, and wetlands. Now, after decades of sand starvation, our coastlines are receding, and we understand that the way we live on the coast is not sustainable. Multiple factors contribute to coastal erosion, both anthropogenic (human-caused) and natural.

Anthropogenic Causes:

Coastal Development: Activities such as paving streets, erecting sea walls, building ports, and developing properties close to beaches hinder natural sediment movement.
Hardening Practices: Structures like rip rap, paving streets, and building jetties can restrict the natural ebb and flow of sediment, causing it to wash offshore instead of moving along the beach.
Damming Rivers: causes sediments to get trapped behind the dam, preventing them from reaching the ocean and being deposited back onto the beach.

Natural Causes:

Sea Level Rise: As global temperatures increase, rising sea levels threaten coastal areas.
Intense Storms: More frequent and severe storms cause coastal flooding and further accelerate erosion.

With more and more of our beaches disappearing, we need to take action. The U.S. Geological Survey estimates that California could lose three-quarters of its beaches by 2100. This not only affects beachgoers, but it also affects dozens of species of animals and threatens the coastline's ability to minimize flooding and other natural disasters.

San Onofre State Beach, 2024. We are experiencing coastal erosion at our home break, San Onofre. In 2024, the road and parking were closed due to the road crumbling and falling into the ocean. People were not able to drive down to the beach and instead had to bike or walk. Reconstruction of the road took several months. This beach was wide and had plenty of room for people to lie out and relax. Now, there is barely enough room for the road. We love recreating in these beautiful zones, but to do so, we also need to take accountability and action to keep our coastlines healthy.

Action: steps to address coastal erosion.

We need to keep our coastlines healthy and mitigate massive sediment transport so that our beaches stay healthy for generations to come. If we lose our beaches, we lose one of the most accessible and affordable ways for Californians and people around the world to spend time outside.

The beach was made to move! We just need to stop disrupting its natural process. To combat beach erosion and manage sediment transport effectively, we can take several proactive steps:

Embrace Living Shorelines: Instead of traditional hardening methods that can exacerbate erosion, we should promote natural coastal buffers like wetlands and sand dunes. Allowing the coastline to ebb and flow helps protect against flooding and storm surges while retaining sand on beaches.

Reduce Artificial Structures: Minimizing the construction of jetties, groins, rip raps, and armored coasts can facilitate natural sediment migration and help preserve our beaches.

Save the Dunes: Sand dunes across the California coast help replenish the sand and act as natural barriers to coastal erosion. See if you can get involved with dune restoration projects in your area!

Restoring California sand dunes.

By understanding the dynamics of longshore currents and sediment transport, we can work towards more sustainable coastal management practices that protect our shorelines. There are large steps, like changing our building practices or voting for legislation that limits building along vulnerable coastlines, and small steps, like biking to the beach, to reduce your carbon footprint. Small or large, whatever you choose to do, remember the impact you have and think about a California without its incredible beaches!