Monday, March 27, 2006
You can't dredge your way out...
The Seychelles' erosion problem seems well researched and the government's desire for technological innovation is laudable. The proposal to disseminate the results and success of this programme to other island nations is also commendable, as this problem is becoming a typical situation around the world. Unfortunately, the typical solution, dredging for beach nourishment, is not sustainable.
More and more coastal areas are trying to dredge themselves out of erosion. It is not working and cannot work. Two U.S. federal agencies, the Minerals Management Service (MMS), which is the agency charged with finding offshore sand for nourishment, and the U.S. Geological Survey, report that topological changes in the seabed slope resulting from offshore sand mining for beach nourishment cause more erosion onshore. The MMS further states that significant coastal impacts could be expected during storm events by increased wave energy striking the shore. The alternative, channel and harbour dredging for sediment, is also known to cause erosion down-current from these sites. In April-May, 2001, government officials on both the west and east coast of Florida have made the same ominous statement, 'We are out of sand'. Dredging is just not sustainable.
Full article (in French as well) at:Full article
More and more coastal areas are trying to dredge themselves out of erosion. It is not working and cannot work. Two U.S. federal agencies, the Minerals Management Service (MMS), which is the agency charged with finding offshore sand for nourishment, and the U.S. Geological Survey, report that topological changes in the seabed slope resulting from offshore sand mining for beach nourishment cause more erosion onshore. The MMS further states that significant coastal impacts could be expected during storm events by increased wave energy striking the shore. The alternative, channel and harbour dredging for sediment, is also known to cause erosion down-current from these sites. In April-May, 2001, government officials on both the west and east coast of Florida have made the same ominous statement, 'We are out of sand'. Dredging is just not sustainable.
Full article (in French as well) at:Full article
