Moving a mountain of sand a mile
By Steve Myrick
Published: November 13, 2008
On an unseasonably warm morning last week, Mark Defeo stood half way up an ever-growing mound of sand and watched thousands of gallons of water, mixed with hundreds of tons of sand, flow out of a large black pipe onto Bend in the Road beach.
His radio cackled. "You should see a burp in about five minutes." Five minutes up the pipe, pressure momentarily dropped, and Mr. Defeo was being advised not to worry when the flow dipped as that "burp" reached the end of the pipe. It actually takes about 12 minutes for the water and sand, dredged from the middle of Sengekontacket Pond, to travel about a mile through pumps and pipes along Joseph A. Sylvia State Beach.
"Once it's here, it's what he saw 12 minutes ago," said Mr. Defeo "I'm in time lapse."
Dredging is a fact of life on Martha's Vineyard. For millennia, nature has pushed, pulled, and redistributed Island sand wherever it wished. But since roads were built and shorelines settled, and visitors came to expect wide, sandy beaches to be in the same places they were when they visited last year, matters could no longer be left to chance.
"We're fighting nature," said Lynne Fraker, dredge administrator for Edgartown, as she stood on a spot where so much beach sand has eroded that the surf sometimes leaves Beach Road awash. "We're making a better beach. There's a lot of benefit, road protection, bird habitat."
Costly, complicated
Moving sand on a grand scale is a very difficult, expensive, and ultimately temporary venture. It all starts with a mountain of paperwork necessary to get an alphabet soup of government agencies to sign off on a dredging project.
For the Bend in the Road project, Edgartown needed approval from the Massachusetts Environmental Protection Act (MEPA) office, the Edgartown Conservation Commission (ConCom), the Massachusetts Department of Environmental Protection (DEP), twice, and the United States Army Corps of Engineers (USACE). The whole process took three years.
"There are a lot of hoops you have to go through," said Ms. Fraker. "They want to make sure that you're not negatively affecting other resources."
Three years of permitting, which includes engineering reports, makes the process expensive even before a grain of sand is moved. Add the cost of labor and equipment, and it is even more expensive. Some of the cost may be recovered through state and federal grants. Some secondary costs, such as planting and landscaping, may be covered by donations. But dredging is still expensive. Edgartown pays less than most towns that require dredging projects, because the town owns its own equipment, including the dredging barge.
"It's not a terribly sophisticated piece of equipment, but it's ours," said dredge advisory committee member Dave Nash. "We have tremendous flexibility about where and how we do our projects. Oak Bluffs and Vineyard Haven don't have dredges; they're going to have to hire people to come over, and it gets really expensive."
The dredging committee estimates the final cost of the current project at more than $300,000. Ms. Fraker estimates that hiring an outside firm to do the dredging would cost $900,000.
Every year since 1996, Edgartown voters have demonstrated their support for the dredging projects by approving Proposition 2.5 overrides to pay for the program. The override requires a two-thirds majority vote at town meeting and then approval by ballot. In fiscal year 2008, voters approved $221,488, and the same amount for the current fiscal year. The town also appropriates approximately $15,000 each year to cover the cost of permits.
Yet everyone understands that nature is a determined foe. The estimated 10,000 cubic yards of sand moved to Bend in the Road beach will eventually wash away, and nature will determine the rate at which it disappears. "It could hang on 15 to 20 years, as long as mother nature cooperates," said Mr. Nash. "This Island and all the sand surrounding us is only temporary, in the big picture."
Mr. Nash cites another part of Beach Road, near Big Bridge, which was threatened by erosion about a decade ago, forcing emergency repairs. "It was all because of a series of storms that hit just right, to cause erosion much faster than anyone expected."
Martian landscape
Unlike most dredging projects, which are focused on clearing navigation channels, or keeping ponds open to the cleansing ocean tides, the Bend in the Road dredging project is strictly about "beach nourishment." In this hydraulic dredging operation, an agitator, or cutter head, loosens sand under the dredging barge, and it is sucked into a large intake pipe. From the barge, the mixture gets pumped through a flexible pipe under Big Bridge, to a relay pumping station located on State Beach. After being transported all the way down the beach, it pours out into a "slurry channel," which is simply a bulldozed trough in the sand. As the watery mixture travels along the channel, the sand drops out and the water continues into the ocean. Heavy equipment is used to continually shape the channel as more and more sand is deposited on the beach. When enough sand piles up in one area, the crew adds another 100 feet or so to the pipe, and begins building up a new section. Eventually the sand will be graded to form dunes and stabilized with vegetation that helps hold the sand in place.
"We're going to shape it in the next day or so," said Edgartown harbormaster Charlie Blair, who oversees the dredging projects. "It looks like a Martian landscape right now."
"But to us, it's beautiful," said Ms. Fraker.
