In the spring of 2012, we were northbound on the Atlantic Intracoastal Waterway (ICW), returning to the Chesapeake from a winter cruise of the gulf coast that had taken us as far west as Galveston Bay. We spent May 5 and 6 at the Dowry Creek Marina – ICW Mile 132, near Belhaven, N.C. – doing those things that boaters on long cruises occasionally really need to do: laundry, house cleaning, changing the engine oil. Early on May 7 we left Dowry Creek, motored up the Pungo River and transited the Alligator River Pungo River Canal (ICW Miles 104.5-124.5).
On this trip, parts of the twenty mile long canal were noticeably wider than they were when we first traveled the waterway in the early 1990s: the banks eroded, old formerly buried tree stumps standing out in the water, fallen trees littering the shore. The canal may have been wider, but mud, sand and silt had narrowed the navigable channel, despite periodic dredging by the Corps of Engineers and the State of North Carolina.
From the Chesapeake Bay south to St. Augustine, Fla, the ICW runs primarily through marshes and low soft, alluvial soils. Both the natural shorelines and the banks of the man-made canals and cuts, except where they have been stabilized with rock or concrete, erode easily and are constantly being reshaped by the tides, currents, winds and the surges of winter storms and hurricanes. Shorelines and banks erode and accrete, sand and mud bars form and move, channels shift and periodically the Coast Guard adjusts the placement of the aids to navigation to compensate for the changes.
Unfortunately there is also an un-natural contributor to erosion and siltation in the waterway, particularly in the narrow, man-made sections — boat wakes. The wakes created by fast moving powerboats thunder ashore in waves that can be as much as three or four feet high. The large wakes sweep ashore and wash sand, silt, debris, sometimes whole trees, into the waterway. About boat wakes and the Alligator-Pungo Canal, the Waterway Guide says, “The canal is relatively narrow and boats dragging huge wakes have a tendency to damage the banks. Each year more and more trees topple into the water.” [page 194]
A recent NOAA study of the impact of boat wakes on the unconsolidated, easily eroded, silts and sands through which many of the man-made segments of the ICW have been cut found that “erosion from boat wakes significantly exceeds background erosion from wind waves.” The study was conducted in North Carolina, primarily in Snows Cut (ICW Mile 295.1), but its conclusions are applicable to the whole of the ICW between Norfolk, Va. and St. Augustine, Fla. and also to much of the ICW south and west of St. Augustine. [See Boat Wakes and Their Influence on Erosion in the Atlantic Intracoastal Waterway, North Carolina, M. S. Fonseca and A. Malhotra, NOAA Technical Memorandum NOS NCCOS #143, March 2012.]
Mid-way through the canal, Betty was driving and I was out in the cockpit trying to get a good photo of a bald eagle. Betty yelled “hold on tight, big wake coming.” I glanced astern and a sport fish boat was coming up fast. Betty tried to call them on the VHF, to ask them to slow down. No response. They passed us at full speed, their large wake hitting us almost broadside. Betty tried to quarter into the wake, but there was neither time nor space. Their wake thundered ashore and washed many feet up into the trees and brush. It was a classic example of what the Waterway Guide and the authors of the NOAA technical paper were talking about.
The Corps of Engineers is the agency primarily responsible for the maintenance and management of the ICW. Maintenance and management cost dollars. An insignificant portion of the cost is covered by a tax on fuel paid by commercial users of the waterway. But the great bulk of the money comes from Congress (often in the vilified “earmarks”) and from the coastal states to whom the waterway is an important economic asset. That is, the money comes from the taxpayers, all of them, not just boaters and marine related businesses. Because of chronic underfunding, particularly since 2000, the Corps of Engineers has been unable to maintain large portions of the ICW at project specifications. Underfunding by the Congress of what should be routine maintenance is a problem the ICW shares with all segments of our national transportation infrastructure.
The price of boat wakes–the price of deliberately damaging parts of the waterway–is increased by expensive dredging and maintenance. These are real monetary costs that have to be paid by someone; costs that we, both cruising boats and local waterway users, may end up paying in the form of waterway user fees and/or higher fuel taxes along the waterway. And controlling dredging and maintenance costs may well result in more, and longer, “No Wake” zones. Think about it.