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12 NATCHEZ ON THE WATERFRONT Don’t dodge dredging By Dan Natchez*


I


f you were to take a worldwide poll, chances are you would find that most people think waterfronts are important,


desirous and, yes, even magical. People want to live at or near the water, whether by lakes, rivers, bays or oceans and most enjoy recreation in, on or alongside the water. For some of us boaters, you might even call getting out on to the water an obsession. However, mention the word


‘dredging’ and many people prefer to dodge the subject. Marina, boatyard and boat club


operators may well agree because they know how critical providing and maintaining meaningful navigable water access is for their operation and how difficult and expensive the whole dredging process has become. Boat owners may also become annoyed if they run aground because either their berth or a given navigation channel has not been dredged. The source of much boater/


operator frustration comes down to what I would say has come to be a prevailing opinion of the public at large, that dredging is an activity that is the source of all things wrong with our waterways. It’s a position that I believe is actually held by a fairly small minority, but that minority has been very successful at getting its view across and driving both public opinion and regulatory policy. Some even say that one does


not have to dredge due to global sea level rise. Actually, sea level rise adds a whole new dimension to waterfront design and issues to debate. One thing that most knowledgeable people will agree on, however, is that sea level rise will not solve the issue of maintaining navigable water depths in any reasonable time period – one is talking about inches over years. The cause of shallowing water depths is not rocket science. The two main causes are upland


MARINA ASIA-PACIFIC • NOVEMBER 2016


siltation into our waters and episodic storms redistributing siltation and/or causing shoreline erosion. In one harbour close to my home base in New York, I happened to undertake hydrographic surveys shortly before and after Super Storm Sandy and found that bottom depths had shallowed by six inches to a foot over most of the area. Of course, on inland waters


There is not a single waterfront facility that looks forward


to the prospect of dredging. It is costly, time-consuming, messy, highly regulated and, at best, is a cumbersome process.


This Model 7012 HP Versi-Dredge unit from IMS Dredgers of Kansas, USA (www.imsdredge.com), can be delivered on the back of a truck. It has been employed at a marina and in the waters of an estuary in Malaysia.


one may also have issues relating to drought or changes in controlled water levels. In most cases, there is very


little that any marina can do to significantly prevent the shallowing of water depths. The old expression may well be that still waters run deep, but in the marina world they rarely do. The very conditions that make for a nice calm anchorage also favour sediment deposition. There is not a single waterfront


facility that looks forward to the prospect of dredging. It is costly, time-consuming, messy, highly regulated and, at best, is a cumbersome process. Most people that become


concerned about dredging actually realise that it is necessary to


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