USA — Navigation study for Canaveral Harbor, Florida

FINAL FEASIBILITY REPORT AND ENVIRONMENTAL IMPACT STATEMENT — 81240. US Army Corps of Engineers, Jacksonville District South Atlantic Division. CANAVERAL HARBOUR FEASIBILITY STUDY — APPENDIX E — COASTAL ENGINEERING ANALYSIS. IMPACTS OF IMPROVEMENTS ON LITTORAL PROCESSES.

Abstract: (from a very long paper)

The US Army Corps of Engineers dredged an initial 27 foot deep channel almost 14 miles offshore to keep the shipping channel clear, but in fact created a massive, hydraulically self-sustaining open pit mine offshore serving to denude the onshore supply and coastline.

Initially, in 1951, 325,000 cubic yards of sand was removed, from 1963 to 1979 the average yearly take was 675,000 cubic yards, and from 1979 to 1990 when the study was made the average was 925,000 cubic yards.

The constant dredging to keep the channel clear and further deepening the original channel continued to promote the loss of both the offshore and onshore material. Studies show the creation of the original channel caused the previously accreting shorelines to begin eroding at incredible rates over forty miles south of the channel dredging. Prior to the dredging, the shoreline was accreting tens of feet per year, so for the visible shorelines to erode in some areas hundreds of feet the offshore had to experience enormous losses in its seabed sediment resources. The effect of the channel dredging was to bring about a steepened and deepened offshore profile, allowing greater storm energies to strike onshore, while at the same time creating a replacement demand resulting in an erosive profile for the nearshore.

The report is thorough, quite comprehensive and detailed, and offers an excellent example of the lack of understanding of coastal physics by the Corps and coastal engineering consultants, and how man can effect massive shoreline changes even with a relatively small project, with far less sediment removal than is taking place off our United Kingdom east coast.

That the dredging took place 14 miles from the coast and brought about so much erosion of the coast is highly significant.


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