Dredging river not a City Council priority
By RUSTY DENNEN
Proposals to dredge the sediment piling up in the Rappahannock River from the Falmouth Bridge to City Dock have received more attention in recent months.
But the City Council has left the issue off its list of priorities for the next two years.
The council’s top priority, announced last week, is developing plans for the 160-year-old circuit courthouse to be vacated when the new one is ready.
City businessman Charles G. McDaniel, who heads an informal committee supporting a river-dredging project, noted the omission on the council’s to-do list.
“I’ve heard absolutely nothing. The only thing I know is what I read in the newspaper,” McDaniel, who lives on the river in the city, said in a recent interview.
It’s significant because any dredging project would need the participation of the city, Stafford County, which owns the river bottom up to the Fredericksburg shore, and the Army Corps of Engineers.
Dredging has been an on-again, off-again topic for more than a decade, particularly since the 1910 Embrey Dam was breached in February 2004.
The Corps of Engineers’ Norfolk District office earlier this year said it would take another look at the problem—at sources of sediment in the river, solutions to stopping the material from reaching the Rappahannock in the first place, and ways to improve aquatic habitat. That effort was shelved, however, because city and agency officials could not agree on the scope of the review, and the city was unwilling to commit to sharing half the cost. About $191,000 in federal funds had been set aside for that study.
Meanwhile, the Corps of Engineers is working with the state on another study, looking at ecosystem restoration and flood management prospects along the entire Rappahannock watershed, Susan Conner, chief of the agency’s planning and policy branch, said last week.
The 2.5-mile section of river from the Falmouth Bridge to City Dock, which has been the focus of local efforts, would be included within that basin-wide review.
“Over the next few months, we’ll be developing a plan and final document. It would include the city, and potentially, if sediment is identified as a problem, it could be looked at,” Conner said.
In April, Claude Shaffer, who is retired and lives in Stafford County, proposed removing more than a million cubic yards of silt in the five-mile stretch from the Falmouth Bridge to Fredericksburg Country Club. He estimated that it would take more than three years to remove that massive amount of material. An average-size dump truck can haul about 5 cubic yards.
Shaffer said he and a Tennessee-based partner, who is in the dredging business, would remove the silt and sell the sand and gravel to cover their costs and make a profit.
But they would have to clear some steep regulatory hurdles before any work could be done, a process that could take years.
Then in August, the informal committee headed by McDaniel announced its effort to gain support for a dredging project. Backers contend that the silt is harming the river ecosystem and is bad for business because it detracts from the Rappahannock’s scenic beauty and limits recreational use. The City of Fredericksburg tour boat still uses City Dock in warmer seasons, but silt has made its operations more difficult.
The committee in August organized a canoe trip in the heavily silted river section for local officials to see the problem firsthand. Three City Council members went along on the outing.
As discussions on what, if anything, to do about the sediment buildup continue, more information is emerging on the source of the material. The sandlike deposits have collected on the river bottom below the fall line and created vast shoals along the shore.
In a draft report to the City Council last year, consultant Resource International Ltd. says the silt accumulation is the result of several natural forces in tandem.
“The river near the city is currently over-wide relative to the size of its watershed, the water slope, flow, and the sediment load that is generated by its watershed,” according to Resources International’s draft report.
It goes on to say that silt has virtually filled in the channel, due to a lack of flow needed to push the material downriver.
That is likely to continue until the silt reaches a state of equilibrium, creating a much narrower channel, it suggests. This raises questions as to whether dredging would be effective, or even necessary.
The U.S. Geological Survey estimates the width of that narrower channel at about 155 to 175 feet. That’s significantly narrower than many spots in the river now.
Resource International noted that the draft’s conclusions did not take into account a silt-related environmental assessment by the Army Corps of Engineers, and a flood frequency analysis. Those were not received before the completion of the draft report.
Fredericksburg Public Works Director Doug Fawcett says the city is continuing its discussions with Resource International on the silt issue.
The company is developing ideas “about things that could be done, focused more on restoration as opposed to a straight-out dredging project,” Fawcett said in a recent interview. He characterized the focus as “working with the river, so to speak.”
CAUSE AND EFFECT
Some have blamed the sediment buildup on the Corps of Engineers, which oversaw the Embrey Dam removal. Prior to the dam breach in February 2004, a contractor removed approximately 250,000 cubic yards of sediment from behind the dam, placing it in a storage area behind the former Bragg Hill Apartments. Another 60,000 cubic yards was removed after the breach when silt remaining behind the dam site began washing downstream.
On three occasions before and after the breach—in 2001, 2004 and 2006—the Army surveyed silt movement in areas below the fall line. Based on those surveys, it has maintained that the general silt buildup is due more to seasonal flooding than anything connected with the dam project.
Erosion from farmers’ fields, construction sites and riverbanks upstream are major sources of waterborne sediment.
The Resources International report, and one by USGS in May 2011, suggest that the sediment bars below the fall line are part of an ongoing process in which silt carried from upstream is deposited in the wider, slower-moving water over time.
The last time the river was dredged, according to one report, was in the 1950s. Since then, commercial boat traffic to Fredericksburg has all but disappeared.
Rusty Dennen: 540/374-5431