TOWNSEND — “Plan your route to work accordingly.”

That was the message Sgt. Jim Peters of the Pepperell Police Department was trying to get across to travelers Wednesday as emergency crews waited to see if the cresting of the Nashua River would cause them to shut down Main Street early Thursday morning.

If it did, Peters said, residents and travelers would have to go all way up to Nashua to get to the other side of the town and points east and west. That is because the covered bridge downtown is closed for reconstruction, and River Street, which connects Route 119 with the traffic rotary in downtown Pepperell, would likely shut down near Groton border. And by afternoon, Route 119 was closed.

During the March 14 to 16 storm, the raging Nashua River washed over part of the Main Street bridge, though the road remained open. Given all the information available, officials expected an exact repeat of what happened two weeks ago, said Frank Quattrochi, the public-safety communications director for the town.

The Nashua River was already gathering strength by midafternoon on Wednesday. At about 2:30 p.m., Quattrochi projected River Street over the Groton border as well as a section of Route 119 over the Nashua River would likely close within the hour.

Quattrochi said the public-safety communications center would have extra staffing overnight to handle phone inquiries related to road closures. Police were closely monitoring the river.

Peters said the town emergency management team met during the earlier rain storm to discuss all sorts of disaster scenarios, including the possibility of shutting down Main Street. The Main Street bridge over the Nashua River closed in 1987 when heavy rains caused the dam abutting the bridge to break.

On Wednesday afternoon, the river had risen and once again, Route 119 near the Pepperell/Groton line was closed.

According to the National Weather Service Web site, the Nashua River was 9.3 feet high at the Main Street bridge on Wednesday morning, compared to the flood threshold of 8 feet.

By way of comparison, the massive mid-March flood that closed the Route 119 bridge for several days crested at about 14 feet in Pepperell. Having seen both floods up close, town Emergency Management Director George Ux thought a repeat was unlikely, saying the river appeared likely to level off, unless there was more rain.

Commuters on Route 119 in Littleton were taking detours because of a failed culvert at Spectacle Pond, near the Littleton/Groton town line. Route 119 from Gilson Road to the Groton town line could be closed for up to two weeks, while state crews work to repair the damage.

In a related note, closure of the Route 119 in Littleton was thought to have contributed to a widespread rumor on Tuesday that the Route 119 bridge over the Nashua River had collapsed. It’s thought to have spread via the Internet, generating numerous questions for town officials. “I’ve had three news stations call me about that,” said Pepperell Fire Chief Toby Tyler. “It’s bizarre.”

Townsend Fire Chief Donald Klein said his department was watching the Squannacook River for flooding.

“We are prepared to pump out any basements we have to, and we’ll keep an eye around the dam area at the Cooperage to see if we have to go back and sandbag again,” Klein said.