BEACH replenishment / norishment
Beach nourishment is the process of dumping or pumping sand from elsewhere onto an eroding shoreline to create a new beach or to widen the existing beach. Beach nourishment does not stop erosion, it simply gives the erosional forces (usually waves) something else to "chew on" for awhile. The waves erode the nourished sand instead of destroying houses, roads or parking lots. Because nourishment doesn't stop erosion, nourishment must be repeated to maintain the beach. This is called "beach renourishment". It's helpful to imagine that each nourishment project (i.e., an addition of a batch of sand) has a "lifetime". The project's lifetime is simply the time it takes for all the nourishment sand to be eroded away. After that time, the beach would be back to its pre-nourishment width, and would need to be renourished with sand.
WHEN IS BEACH NOURISHMENT AN OPTION?
Beach nourishment is often proposed when beach erosion threatens to remove an existing beach, make it too narrow to be used, and/or when property behind an eroding beach is threatened. Publicly funded beach nourishment is worth considering only if the general public will have good access to the "new" or restored beach, AND when all parties have been informed that this solution is temporary, and will have to be repeated. Publicly funded beach nourishment is foolish if only a few beachfront property owners stand to benefit.
- Nourishment restores and widens the recreational beach.
- Structures behind beach are protected as long as the added sand remains.
- When erosion continues, beach nourishment does not leave hazards on the beach or in the surf zone. This is a big advantage when compared with "hard" beach stabilization structures like seawalls or groins. Seawalls may protect structures behind the beach, but they almost always cause the beach in front of the wall to become narrower. If erosion breaches the seawall, then debris from the wall will be left on the beach and in the surf. Since beach nourishment only puts sand on the beach, no debris is left when it erodes.