NEWRY – Manipulation of the Bear River channel many years ago was identified Thursday night as one of the “most likely” causes of the river’s instability problems.

Other factors included substantial erosion from abandoned and unmaintained, old logging roads in the upper watershed’s remote regions, said Jeff Stern.

Stern is a member and project consultant of the Bear River Watershed Committee.

The committee consists of a group of landowners and municipal officials who have been trying to identify and lessen nonpoint source pollution problems in the watershed.

These problems have caused the river to jump out of its channel, significantly erode stream banks and create new lanes on its nearly 10-mile-long rush from Grafton Notch to its confluence with the Androscoggin River.

“It’s important to know how the river is behaving when you’re trying to fix stream bank erosions problems,” Stern said, of the significance of the survey and subsequent stream habitat and assessment surveys.

At Thursday night’s 90-minute meeting in Newry’s town office, Stern shared the results of this summer and fall’s walk-through survey of the watershed with about 20 people.

Among the 132 identified erosion sites, 37 were on stream banks, 30 on logging roads, 15 on state roads, 13 in a new channel, 10 on hiking or snowmobile trails and seven on driveways.

“A lot of the river’s instability can be found in Grafton Notch State Park. There has been a lot of manipulation of the river over the years, like the channel straightening in the park,” Stern said.

Another stretch further downstream appeared to have been straightened as well, he added.