The town of Walpole has received state funding to replace a culvert that currently poses a flood risk and a barrier to aquatic animals in Houghton Brook.
On Friday, the N.H. Department of Environmental Services’ Aquatic Resource Mitigation Fund Program announced that the culvert replacement is one of 16 projects around the state being awarded a total of $3 million — 11 conservation projects and five stream restoration projects. The Houghton Brook project will receive $250,000.
The existing 13-foot metal pipe is too small and would not be able to convey a surge from a 100-year flood, according to the release. The new, 24-foot-wide span will provide easy passage for animals and sediment, and accommodate severe storm flows.
According to the release, the current culvert is deteriorated and the adjacent stream banks are “severely eroded.” The replacement project will increase hydraulic capacity and improve the habitat for fish and other wildlife in the brook, in particular brook trout, which will regain access to upstream spawning and foraging habitats.
Walpole Selectman Steve DiLessio said that in addition to the culvert, the bridge there is also in bad shape, and both need to be replaced. He said the grant will cover roughly half of the total cost of the project, and the bridge and culvert will be replaced at the same time.
When it comes to wildlife in the brook, he explained that the conditions around the bridge and culvert have caused the formation of little pools at different heights, making it difficult for animals to travel upstream.
He also noted that the bridge serves a dead-end road, so if anything did happen to the bridge during a severe flood, residents could find themselves in big trouble.
“We always want to prepare for these 100-year floods,” he said. “Should we get another 100-year flood, and bridge is washed away, people would essentially be landlocked on the other side.”