Dredging 101: New estimate at $25-30 million

Chris Gibson teaches Dredging 101 at the Design Center downtown.

Until a few months ago, dredging had all the glamour of using diesel equipment to pump mud off a lake bottom. Which of course is what it is.

But Monday night, May 5, two guys in suits gave a "dredging 101" slide show that packed the old downtown visitors center with over 60 people.

"Dredging is a fancy word for digging dirt underwater," said one of the suits, Chris Gibson. By the end of the evening, the vice-president of Wilmington, Delaware-based Gahagan & Bryant Associates was tossing out ballpark figures of what dredging should cost this community. And, unfortunately for would-be entrepreneurs hoping to leverage a "Mudcat," a "Dragon," or even the evening's touted device– a 1,200+ horsepower "Wilko"– into hundreds of millions of dollars at the Rivanna Reservoir, such hopes are sinking into the turbid waters of reality.

Four years ago, after two unsolicited proposals landed at the then-leaderless Rivanna Water & Sewer Authority, the Pennsylvania-based firm that was busily rewriting Charlottesville's 2002 post-drought water plan declared dredging too expensive. The firm, Gannett Fleming, had yet to  be vilified as the designer of a system of eventually fatal overhead concrete panels at Boston's Big Dig. Here, the firm simply claimed that dredging, which doesn't appear to be one of its specialties, would cost up to $225 million, the bulk of the price based on the questionable theory that most of the dredged material would be loaded in trucks and driven away.

"You could haul it to D.C. for that," Gibson told the audience. "That seems like a high cost."

In contrast to Gannett Fleming's vision of thousands of trucks hauling five million cubic yards of material over 50 years, Gibson suggests that the local dredge would probably need to move only 1.7 to 2.5 million cubic yards, as the reservoir is not choked enough to produce so much.

He estimates a total of just $25-30 million for the project and says his firm would like to conduct a full-blown feasibility study to establish a firmer estimate– which he says is usually five to ten percent of the eventual cost. The "tipping fee" paid to any landowner with at least 50 spare acres to clog with mud and sand might bump up the cost a few more million.

"Ultimately, disposal site selection is the cornerstone of any good project," said Gibson. "You need a hole. Whether you find one or construct one, that's what you need."

He and his associate, Rob Kite, said they examined two tracts near the reservoir, including Panorama Farm, a site already known for dirt-farming (it sells a compost called Panorama Pay-Dirt). Gibson called Panorama a "perfect" site thanks to its plentiful acreage, its mid-dredging zone location, and its shallow rise above the pool.

(Dredging advocate Rich Collins pointed out that the owners of Panorama haven't expressed an interest or disinterest in such a project yet.)

At the meeting, Gibson conceded that dredging would probably require an Army Corps of Engineers "401" permit, but he tried to assuage attendees– who included Authority director Tom Frederick– over some of the concerns that have erupted in recent days, now that dredging is finally taken seriously. Frederick and his board have thrown their support behind a $143 million plan to upgrade two treatment plants and create a new Interstate highway-hugging, pipeline-dependent reservoir that requires the felling of 180 acres of mature forest.

River-loving attendee Leslie Middleton, who hosts a weekly five-minute radio program called the Rivanna Rambler, blasted the Hook for providing "partial information" that she says has fostered "divisiveness." She says she supports both maintenance dredging and the $143 million plan.

"It's an odd, multi-faceted, and– to my understanding– elegant solution to a lot of problems," Middleton said. The plan is projected to restore historic stream flows on the Moorman's River by pumping water out of the Rivanna Reservoir during wet times and storing it in the proposed jumbo reservoir.

One thing everyone can agree on is that the 42-year-old Rivanna Reservoir is filling with sediment.

"Today," said Gibson, "we were running aground in a boat that drew eight inches of water, and I couldn't see the bottom. That's turbidity."

In response to a question from the audience, Gibson said that a full-blown feasibility study by his firm will cost about $275,000, and would include lake-bottom imaging, geotechnical probing, sediment sampling, and door-to-door surveys to find a disposal site.

Another attendee, Mitch King of Blue Ridge Sand Inc., offered one of the two unsolicited bids from four years ago. He wants to win the dredging business and would employ a system of sluices that simultaneously dewater and classify the material for greater marketability to contractors and landscapers."We need about three acres," he said.

Don Meyer, owner of the other unsolicited dredging firm, Dock Doctors, who was also in attendance, said he plans to buy a farm with the proceeds and create wetlands on the parcel to earn credits for any environmental damage that might occur. He'd offered to perform the dredging for just $21 million.

Dredging supporter Joe Mooney, one of the people who encouraged Gahagan & Bryant to come to Charlottesville, was asked what he thought of it all.

"I don't know," said Mooney, who slipped into the meeting around 9pm as it was ending, "because I was over at the City Council meeting talking about William Crutchfield's letter."

The founder and CEO of one of the nation's biggest consumer electronics retailers, Crutchfield recently entered the fray with a letter that questioned the expertise of the Nature Conservancy, asked about a potential Gannett Fleming conflict of interest, and worried about the carbon footprint of a system dependent on pumping water uphill. 

"Prudent businesspeople," Crutchfield wrote, would have gotten a second opinion on dredging. That's what Gibson wants to provide.

"It's not a real complex project," said Gibson. "It's not a real big project. It's middle of the road."


This story is a part of the Water plan all wet? special.
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