What is Beach Nourishment?

Beach Nourishment

The natural forces of coastal storms, wind, tides, waves and currents constantly move sand along our coast. Coastal engineers call this process “longshore drift”. Some of the sand is carried further down the beach while some of it is carried offshore into deep water. This is the same motion that carries swimmers in gulf waters down the beach and away from their towel. Overtime, these natural forces can cause the width of the beach to narrow and move landward. Beach erosion refers to this loss in the volume of sand and the advancement of the shoreline landward. Waves and storm surge can cause significant destruction to an eroded beach resulting in the loss of property, wildlife habitat, and recreation.

Beach nourishment is a shore protection project designed to reduce or prevent the consequences of beach erosion. It is the only shore protection method that adds sand to the coastal system and is the preferred method for shore protection today. During construction of a beach nourishment project on Captiva Island, a propelled floating plant, called a hopper dredge, brings large volumes of beach quality sand from a borrow area approximately 8 miles off the Captiva coast. The ship vacuums sand from the sea floor through drag arms that load the material into the hold of the vessel. This cargo of sand is then sailed close to shore, where it is pumped ashore through large pipes.

Ultimately, the wider nourished beach, which slopes gently downward below the water, and the taller sand dunes protect the shore by acting as naturally protective buffers. Like any other major infrastructure, restored beaches must be maintained to stay healthy. Think of Captiva’s beach like a road, requiring periodic resurfacing with sand. To ensure that the nourished beach continues to provide protection and mitigates the effects of hurricanes and coastal storms, the project must be supplemented with additional quantities of sand, called beach maintenance, as needed.