CONWAY — Kicking off an informational session at last week’s Planning Board meeting, a member of the Friends of the South River shared a video of flooding caused by Hurricane Irene in 2011, demonstrating the impact the storm had on the river downtown.
“The water was coming down Academy Hill Road — because Pumpkin Hollow Brook overflowed — and heading down Main Street,” said Michelle Turre, narrating the video. “The bridge over Main Street, down closer to the Post Office … that bridge, the abutment, washed all out on the upstream side, and the water was overflowing there as well.”
The informational session on Jan. 21 was the first opportunity for town officials to discuss river corridor protection efforts, which includes their consideration of adopting a River Corridor Protection Overlay District.
Town Administrator Tom Hutcheson explained that the concerns of the South River — which have been exacerbated by more extreme weather events — are among the issues identified in two documents: the Hazard Mitigation Plan, an all-hazards plan, and the Municipal Vulnerabilities Preparedness Plan, which focuses in particular on mitigating the effects of climate change.
“As we complete these plans, we not only raise the level of awareness of environmental risk,” Hutcheson said, “but it allows us to apply for grants that address the plan’s purposes, and the goals and objectives identified in the plans.”
Kimberly Noake MacPhee, land use and natural resources program manager with the Franklin Regional Council of Governments (FRCOG), said her organization has been working with Ashfield and Conway since Hurricane Irene on assessing and identifying climate-resilient strategies for the South River Watershed.
In addition to flooding caused by “inundation” — severe rain events contributing to rising water levels — Conway also experiences other hazards related to flooding, such as “fluvial erosion,” or river-related erosion to the riverbanks.
“The typical engineering response to these erosion hazards has been to build retaining walls,” Noake MacPhee said. “But the problem with these armored solutions — these Band-Aid approaches, or just focusing on a site that is threatened or in peril — is they typically fail, and they fail again and they fail again.”
Instead, especially when considering impact of climate change, the goal should be to “focus on the entire river and its watershed lands, not just the problem area,” she said.
After reviewing some of ways the South River has historically been negatively impacted — including roads and other developments in the flood plain, land clearance, river straightening (to accommodate mills) and the removal of boulders, among others — Noake MacPhee explained the strategy of mitigating the effects of these historic uses is “avoidance.”
“Rivers need room,” she said. “They are dynamic, natural systems. Their work … is to transport water and sediment.”
That’s where a River Corridor Protection Overlay District comes in, she explained.
“By definition, an overlay district has more stringent requirements than the underlying zoning has,” Noake MacPhee said. “It’s an extra layer of protection. The purpose … is to limit new development and control the expansion or alteration of existing structures.”
In an overlay district, there are few permitted new uses, she explained, and the list for uses that can happen require a special permit.
“A model (overlay district) is a good starting point for the town of Conway, to have discussions like we’re having now, to learn more about the tool and to customize it for the town and to meet the town’s needs,” Noake MacPhee said, referring to the model developed by FRCOG.
Planning Board member Mary McClintock reminded those at the meeting that in terms of the potential for a River Corridor Protection Overlay District as described by Noake MacPhee, the town is still in “the very early stage of conversation.”
“We’re learning in this process, and we will have discussions about this in the Planning Board,” McClintock said. “If we decide we want to go ahead with something like an overlay district, that would be a zoning bylaw change and that would mean that we would probably have another info session, definitely would have a public hearing, and it would need to go to Town Meeting.”
Mary Byrne can be reached at mbyrne@recorder.com or 413-930-4429. Twitter: @MaryEByrne