Thursday, December 5, 2013
FARMINGTON — As the snow begins to melt and fill the Sandy River with spring runoff, the public works department will be closely monitoring erosion along Whittier Road.
Snow and frozen ground on Thursday have stabilized the eroded bank between the Sandy River and Whittier Road in Farmington, but officials are concerned about the effects warm temperatures and spring rain will have on the riverbank.
Staff photo by David Leaming
Farmington's public works director said his department has heightened concern that the river will swell and collapse the road, or at least damage it enough for the town to close the section as a precautionary measure.
Progress on the pending project to fix the road has been delayed for permit reasons. Some people are concerned not only about the safety of the road, but also because of the short window U.S. Fish and Wildlife Service allows the town to perform construction near the river.
Director of Public Works Denis Castonguay said he has been checking on the riverbank daily to see if the unstable part of the bank has compromised the road.
"All it would take is one high-water event," Castonguay said.
The town has been working with Jones Associates, an environmental consulting group, to stabilize the bank, but the project has been put on hold while the permit is processed.
Consultant Rick Jones said the group is trying to work toward an agreement with U.S. Fish and Wildlife Service about what type of structure they will be building to stabilize the bank.
The consulting group was planning to build a $277,170 project that would shore up the eroding bank using rootwads, which are tree bottoms driven into the bank with the intact root balls facing out to catch silt and hold the soil.
U.S. Fish and Wildlife Service officials recently proposed an alternative wood post structure that would use wood debris to stabilize the bank.
Jones said his group does not think the wood post structure would hold up, and his group is concerned the town will need to pay for the project to be revisited in a few years.
"Everyone we've talked to is concerned with the structure's longevity," he said.
Jones said they will need to reach a consensus soon because they have a short timeframe when they are allowed to build along the riverbank.
Work to prevent further erosion and road damage must be done during a time least harmful to the endangered Atlantic salmon's spawning ground. Jones said the construction work has to be completed between July 15 and Sept. 30, which is when Atlantic salmon are least susceptible to harm from construction.
The project took a small step forward about a month ago when the Federal Emergency Management Agency responded to the original project proposal for a rootwad structure. Jones said consultants originally expected to hear back from the agency shortly after Christmas.
His group is now working to reach a consensus on which project to build and get the final project approved by FEMA.
After that, the U.S. Fish and Wildlife Service will evaluate the project and consider whether it violates any of several federal laws, including the Endangered Species Act.
The environmental consultants were hired by the town to stabilize the bank after tropical storm Irene caused a 50-foot-wide, 300-foot-long chunk of the bank to fall into the Sandy River in August 2011. The ground between the riverbank and the road has been eroding since, threatening to collapse the road into the river.
Whittier Road was closed briefly in November because of erosion and its effect on the road's stability, but it was reopened following complaints from those who use the road.
When the road was reopened, Castonguay said there were lower water levels on the river and colder temperatures that slowed erosion and made the prospect of a collapse less likely.
But in the coming weeks as temperatures warm, erosion will likely pick up and flooding may occur, he said.
As a safety precaution, traffic has been limited to the lane farthest from the river since the road reopened.
Kaitlin Schroeder — 861-9252