| Understanding Our Dunes | What Causes Erosion |

| Barrier Island Processes | Historical Data |

Why are dunes important along the coastline?

Dunes act as a storage reservoir for sand that is made available during infrequent but severe storms. The larger the dune, the more time it takes to be eroded by the waves, and the more protection it provides to houses, roads, and infrastructure farther landward. If the dunes are large enough, the waves and storm surge are prevented from washing across the barrier island.  Flooding may still occur from the backside of the island but not directly from the ocean. Even if the dune is breached and the shoreline is overwashed, the sand stored in the dunes and eroded by the storm reduces the incoming wave heights compared to areas without dunes.

In the simplest terms, sand stored in the dunes buys time and protection from the worst storms. The bigger the reservoir of sand, the more time it takes for the waves to consume the dune. Both natural and man-made dunes provide significant protection from storm-induced erosion that occurs during infrequent severe storms, such as a hurricane.

Dune vegetation: Coastal dune plantings also help build new ecosystems. The new plants are small and need time to grow, so please respect the dune and the new plantings and do NOT walk on the plants.  Once these plants are mature, they will provide a way for the dune to continue to grow, catching the sand that the onshore winds blow from the lower beach area further landward, helping the dune to grow and widen naturally.

What causes erosion?

Coastal beach erosion is the gradual wearing away of the shoreline due to the combined forces of waves, tides, currents, and rising sea levels. Florida's East Coast, with its low-lying geography and dynamic weather patterns, is particularly vulnerable to this phenomenon.  If there were no infrastructure on the beach, then erosion would not be a problem and there would always be a beach.  It becomes an issue when humans build roads, buildings, and infrastructure along the coastline and the want the beaches and dunes to not move. Beaches are dynamic environments and have migrated inland as sea-level has risen over the past several thousand years.

What can be done to protect the dunes in Flagler County?

The best way to protect the dunes from erosion is to build and maintain a healthy beach in front of the dunes.  If the beach has been eroded to a narrow and steep beach, such as most areas along the coast in Flagler County, then the ocean can interact with the dunes on high lunar tidal cycles and smaller, more frequent coastal storms.  By building and maintaining a wide and elevated beach berm in front of the dunes (which also provides a recreational beach and many other benefits) the dunes will only be eroded during the largest coastal storms, such as hurricane events, and will provide the much-needed barrier to protect inland infrastructure.

Historical Data 

Under development - please be patient with us.

CONTACT

P. Ansley Wren-Key, Ph.D.
Coastal Engineering Administrator
(386) 313-4112 | awren-key@flaglercounty.gov
Monday - Friday: 08:00AM - 05:00PM
1769 E. Moody Blvd., Bunnell, FL 32110