Survey identifies problem areas on Gunstock River

GILFORD — A recently completed study regarding the health of the Gunstock River and the amount of silt that empties into Lake Winnipesaukee showed two key areas where experts recommend remedial action.
Two of the higher priority areas are around culverts, including the one that crosses Cherry Valley Road and provides access to the Town Highway Garage, and the Intervale Road culvert.
"Something's got to be done (on Intervale Road)," said Everett McLaughlin, who is on the Conservation Commission that will get a presentation on the final report Tuesday at 7 p.m. from Lisa Morin of the Belknap County Conservation District.
McLaughlin said the report confirms that one of the reasons for much of the stream bank erosion near the Intervale Road box culvert is because the road and culvert are perpendicular to the river.
"It was a a mess last year and it did it again this year," McLaughlin said, referring to the erosion that releases silt and phosphate contaminants into the lake through Sanders Bay.
Morin said six miles of the Gunstock River were evaluated by a fluvial geomorphology study funded in part by the Belknap County Conservation District and the Samuel Pardoe Foundation. Bear Creek Environmental, LLC of Vermont completed the study in 2012. Morin explained that the study is really a "snapshot" of the river at a period in time.
The report said there are a total of 18 stream crossings – 14 bridges and 4 culverts – that were evaluated. Eight total structures were identified as high priority with the two culverts mentioned above and a culvert in an unnamed tributary identified as "the Trail to Lyman's" are the most incompatible with aquatic organisms including adult salmonids.
Morin said there were several healthy places on the river, defined as places where the stream bank provides good habitat for fish and wildlife. She also said there were several places where erosion adds nutrients and some places where there is "significant turbidity."
She said it would be her recommendation to create a short-term committee to that identified the town's priorities regarding the river.
"We already know Intervale Road is a town priority," she said, noting the town already knows the N.H. Department of Transportation has no plan to rebuild the Intervale Road culvert. She said one possible solution would be to remove some of the fallen trees and install rip-rap along the bank with the most erosion.
She said once the town had identified its priorities then her agency would help with finding and applying for grants to do the work.
Morin said at this point in time, no decisions have been made.