FARMINGTON — Town officials are hoping that the winter freeze comes before heavily traveled Whittier Road has to be closed because of erosion.

Meanwhile, the cost of a long-term solution continues to mount and a local expert says even a freeze may not bring a temporary stop to the problem.

Public Works Director Denis Castonguay said Wednesday the riverbank is about 30 feet from the pavement and if the bank loses another three feet, the town will probably close the road.

The erosion, which began with Tropical Storm Irene in August 2011, has steadily eaten away the riverbank — about 16 feet since April. Castonguay said the bank lost about nine feet between April and June, another two by mid-August and five since then.

While town officials can’t estimate how long it will take for three more feet to go, preparations are being made in case the road has to be closed.

If the road isn’t closed before winter, Castonguay said officials believe the embankment will probably last through the season, bringing temporary relief.

“The embankment itself will harden, so the sand won’t keep tumbling down,” he said. But he added that if the road remains open through the winter, the rushing water and soft ground that come with the spring melting will be a problem.

But winter may not bring the temporarily relief the town hopes for, said John Lee, who manages the environmental physics group at the University of Maine and lives on the river. He said ice floes that are pushed against the riverbank by the water during the winter can act like shovels, posing a different kind of threat to the sandy soil that gives the river its name.

Fluctuation in winter temperature can also cause the water level to rise and fall, grinding sheets of ice against the bank.

“One of the biggest factors I’ve noticed is ice scraping the banks,” he said. “I’ve had many yards of soil taken away by a sheet of ice.”

Last week, the public works department built an extended driveway that will allow access to a property on the road that would be cut off if it were closed.

In September, state emergency officials coordinated a meeting with the Maine Army National Guard to discuss building a bypass behind five homes on the road.

The town has been trying for months to get permission and money for a long-term fix, a $277,000 stabilization project that would use masses of tree roots to shore up the riverbank.

The project was put on hold over the summer because of concerns from the federal government about a potential negative impact on the endangered Atlantic salmon, which uses the river as a critical spawning habitat.

Town Manager Richard Davis estimated that the delay has cost the town about $30,000 so far.

If the road fails, Davis has said that the cost to rebuild would be an additional $500,000.

The town has applied for a grant from the Federal Emergency Management Agency that would cover about 75 percent of the stabilization project cost.

Matt Hongoltz-Hetling — 861-9287

mhhetling@centralmaine.com