Beach replenishment in Negril
THE EDITOR, Sir:
It seems that you or some people object to breakwaters or artificial reefs that can knock down turbulent waves and replenish a beach at the same time.
The question raised had to do with whose sand is being taken when breakwaters replenish the beach. It seems that the philosophy up and down the eastern seaboard of the USA and now in Jamaica that it is wrong to take sand from the near shore and replenish a beach using artificial reefs, but it is with the government's blessing to take sand from off shore and do the same thing. One could say, "Mother Nature wanted the sand in both places otherwise she would put it someplace else", and we shouldn't mess with Mother Nature: so goes an old TV commercial.
I have run wave tank tests on the effectiveness of WADs ( Wave Attenuation Devices). I discovered that when the near shore sand availability ran low, beach replenishment stopped, even though sand still available. When I artificially added more sand to the tank on the ocean side of the WAD deployment beach replenishment started again. In an eight-foot long, 18-inch wide wave tank, I had to manually replenish the ocean sand availability by about 250-300 pounds. It seems to me that when WADs are deployed and begin to work at replenishing the sand from the eroded beach that the only sand that is being returned is sand that was originally on the beach. It certainly is not sand that is 1-2 miles off shore.
I think that before Jamaica, et al, embark on a two-fold measure to replenish its beaches that a careful study be made of where the sand, (from off-shore or from near shore) actually came from. Sand by its nature has its own signature which makes this study fairly easy to do. To arbitrarily say that the near shore sand actually belongs to someone else is, until a study is done to determine the original location of the sand, wrong.
37 Indian Trail
Scituate, MA 02066fs