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<br />7 <br /> <br />/ <br />..// <br /> <br />Gerd Marggraff (51D-828-1992) <br /> <br />/ <br /> <br />tests using water dyes could establish the current flow and current direction for <br />our channel to optimize the time of dredging with respect to the tides. <br /> <br />Most of the time, these systems are used to maintain a depth, not so much to <br />create new channels, as there are limits to the density of the sediment that can <br />be removed without a cutter-head dredge. For instance, if we had had one of <br />these agitating dredges working in our channel from the time it was brought to <br />depth with the last cutter-head dredging, we would not have draft problem now. <br /> <br />For the pessimists in the audience, who will say agitation dredging has not been <br />done in this country, I must say you are wrong. In Florida, every year, millions of <br />tons of sand are removed by marine archeologists using a System 2-like <br />technology. <br /> <br />Let us talk a little about cost. All three dredging systems could be installed on a <br />second-hand work boat or tug. I have done a little bit of market research and <br />have found a few boats 50-60 ft in length under $200,000. Given my experience <br />in the maritime industry, I would estimate the refit cost for one of these vessels to <br />be $50,000-100,000. The actual operating expenses of this size workboat would <br />include 2 crew members, diesel and maintenance cost for the vessel, and fixed <br />costs including insurance for 2-5 days a month. This creates a financial framework <br />that could be easily handled by the City or a private contractor. <br /> <br />Before I close, I would like to mention two other things: <br /> <br />1) When we came into the area, we were told the marina channel was access <br />to the Oyster Bay, in case of aviation disaster. Why is it, when the airport is <br />expanding, they are no~ asked to contribute to the dredging? Are they <br />100% sure there will be no disaster? It would be interesting to read their <br />emergency response plan. <br />2) My research in to water-front development has yielded an interesting <br />website: http://www.pps.org/info/newsletter/february2007. The site <br />describes in depth, how to redevelop neglected waterfronts, especially the <br />mixed business developments. This should be of interest to the City & <br />community. <br /> <br />- 3- <br />