Editors, The News Journal 14 March 2003
 
The Volusia Flagler Environmental Coucil is pleased to submit the following for Community Voices.
    From recent presentations, newspaper articles and discussions, it seems that more and more people are becoming concerned about the beach erosion we have experienced over the years, as well they should. The level of the sea is rising, and the rise amounts to almost exactly a foot in the last century. A foot of rise means that the beach has moved westward in this area by from 20 to 50 feet, depending on whether the sand is coarse or fine. And the rise is continuing, and may even speed up. Sea level change, both rise and fall, has occurred in the past. The DeLand Ridge, Rima Ridge, and the ones at Clyde Morris and Ridgewood Avenue are old sand dunes, left as the sea fell in the ice ages. It's now rise rather than fall. So the beach wants to move to the west.
    It seems that a lot of persons believe that our "sea walls" will take care of the problem. They will not, for the simple reason that we do not have seawalls, but only sand retaining walls. To make this clear, a true sea-wall must satisfy all of the following requirements.
    -It must be high enough so it will not be over-topped by the storm surge which happens when the eye of a hurricane reaches the shore, nor by the waves on top of the rise. In this area, the wall must extend to about 20 feet above normal sea level.
    -Its foot must be buried deep enough that waves cannot remove the sand from the base, a minimum of 4 feet for average sand.
    -To further prevent being the wall being underminedby the downward splash when a wave hits an object , some form of "toe scour protection" must be used. The best means resemble the 6-prong jacks that children play with, but in reinforced concrete, and grown to 6 feet or more in size, placed in an interlocking layer along the wall base.
    -The wall must have strength to withstand repeated impacts of waves, of up to 6000 pounds of force per square foot of wall, repeated several times a minute for from hours to days.
    -To keep the wall from vibrating at wave impact, and cracking, there should be no joints, and there must be a cap along the top, anchored to the wall, and of sufficient weight to counter the buoyant force of the rising water on the wall.
    -To help these last two items, proper design also includes sloping back braces, from the top of the wall to footings buried well back of the wall.
    -Finally, unless the wall adjoins similar walls at each end, the wall must be carried along the property sides; 20 feet is a minimum and good design needs more.
    The Environmental Council has not made a full engineering evaluation, but members have inspected most of the walls in the County. Even a casual look shows that most do not meet sea wall requirements, being too low, made from concrete block, already cracked and having gaps and/or joints. Watching recent installations shows that they are not much better, not being buried enough, having cracks, no toe scour protection, no anchors for the top cap and no back bracing. The best are the sloping granite block "Revetments" near the south end of the County, but some of these have not been buried deep enough, and most depend on plastic mat to keep the sand from washing through the space between the face boulders. Plastics degrade in time, so this type of protection must be completely rebuilt at intervals.
    The walls facing the ocean in this County are sand retaining walls, most built to give a level space for a patio, a shuffleboard or a swimming pool. A number of these could not withstand the 1989 Thanksgiving Day north-easter. They failed, leaving wall, shuffleboard and even swimming pool debris lying on the beach. Even the later ones are also retaining walls, built to give parking space for as large a building as possible.
    Ocean front property owners should get some cost information before they even think of committing to hard armoring. And they should investigate another matter--why walls reached by waves at some stage of the tide increase beach erosion, to the point that they eventually cause death of the beach in front of them by erosion.
    What will we advertise if everybody exercises the "right to protect" their property? Come see our beautiful walls- see how nicely they are painted!

Prepared during the month of February, and reviewed by the Council at its meeting of 12 March.
 

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