Conservation commissioners flag beaver dams, high water as risk to rail-trail; consider contractor work

Milford conservation volunteers and commission members told the commission they have found active beaver dams and high water backing up behind multiple impoundments that are pushing water onto the rail-trail, threatening embankments and culverts.

The discussion centered on recent field observations at Compressor Pond and the Halstead and Dickerman impoundments, where volunteers and landowners cleared beaver dams and installed flow devices. Commission member 2 said property owners had "opened up the dams" on the private parcels feeding Compressor Pond and had installed a device to manage flow, which helped explain where the extra water was coming from.

Commission members and volunteers described how water from the rail-trail corridor flows northerly under Ranalla Road and Malendi Road into Compressor Brook and Compressor Pond and noted that clogged beaver activity and undersized overflow culverts are creating bottlenecks. Commission member 2 said the group that repaired the trail in February had installed a short overflow pipe that now acts as a bottleneck, and commission member 6 recommended extending or enlarging the pipe and reinforcing the embankments.

Commission member 2 and others raised options that included: extending the overflow culvert under the trail, reinforcing embankments with rock or wire to prevent animals from undermining the banks, and adding harder surfacing where washout is occurring. The group noted one existing low section that was underwater in May 2023 and said raising that section of trail and lengthening the overflow culvert would reduce washouts.

The commission reviewed funds available in the trail account. One member said the balance appeared to be about $50,000; later in the meeting another member said the fund looked closer to $70,000. Commissioners agreed it would be more cost-effective to address culverts and embankments before a larger failure occurs. "If we don't do something it's going to cost us and the town so much more money down the road," Commission member 4 said.

Next steps described at the meeting included asking a contractor (referred to as Mike in the discussion) for an estimate to excavate and reinforce the narrow section south of Malendi Road, lengthen or upsize the overflow culvert, and install anti-undermining measures along the embankment. Several members suggested organizing a trails committee or volunteer watch group to monitor beaver activity and water levels and to coordinate with property owners who have already taken action.

No formal motion to spend money or to authorize a contract was taken at the meeting. Commissioners directed staff and volunteers to contact contractor Mike for an estimate and to convene the trails committee to develop a longer-range maintenance plan.

Potential immediate safety concerns were also raised: leaning trees along the trail that are at risk of falling into embankments, and bank erosion in places such as Keyes Field and the Boys & Girls Club bank. Members recommended clearing hazardous leaning trees and asked staff to check the priority list for tree removal.

Commission members emphasized treating the drainage system as a network: any fix in one spot requires attention upstream and downstream because water moves through the system. They also noted that some landowners along the corridor are carrying out private dam maintenance and have installed devices to manage beaver flow that have reduced pressure on downstream structures.

The commission agreed to ask Mike for a written estimate and to consider using trail funds for work to shore up the culvert and embankments. Commissioners said they would follow up with a plan if estimates and permits allow.