Wetlands Commission Okays Merwin Meadows Pond Dredging for Memorial Day Opening

After two years of waiting, Wilton residents can look forward to swimming in Merwin Meadows Pond this Memorial Day weekend thanks to a unanimous vote by the Inland Wetlands Commission (IWC) in favor of dredging the pond and beach to remove silt deposited there during the August 2024 floods.

The vote, held during a special meeting on Tuesday, Apr. 21, was the final step required for the Parks and Recreation Department to undertake the eagerly awaited restoration.

Earlier this month, Parks and Recreation Department Director Steve Pierce went before the Board of Selectmen (BOS) to request $374,114 for the dredging project, recommending that it be allocated from the town’s pond dredging and operating capital accounts as well as from unused American Rescue Plan Act (ARPA) infrastructure funds.

As GOOD Morning Wilton previously reported, the town hopes to be reimbursed for 75% of the remediation costs by the Federal Emergency Management Agency (FEMA) once the partial federal government shutdown ends.

Entire Project Expected to Take Three Weeks

The dewatering, dredging, and restoration will be conducted by Torrington-based Yield Industries LLC under the supervision of Rocky Hill engineering firm Weston & Sampson. Pierce told the commissioners that he anticipated the dredging would get underway as soon as the contract with Yield is signed — which the BOS has authorized First Selectman Toni Boucher to do — and the project would take approximately three weeks to complete.

“Obviously, if we get approval, we would move ahead expeditiously because we’re trying to get it open for the summer season,” Pierce told the commissioners before the vote.

With a little over four-and-a-half weeks left before Memorial Day weekend, that would seem to leave little leeway for unanticipated delays.

According to the plans submitted by Weston & Sampson to the IWC, the project will involve:

• Draining an estimated 1.5 million gallons from the pond and discharging the filtered water into Comstock Brook
• Removing approximately 495 cubic yards of sediment from the pond and another 485 cubic yards of sand and silt from the beach area
• Removing the sediment to the Department of Public Works (DPW) construction yard
• Adding a “top dressing” of new beach sand to the shallow end of the pond as well as the beach itself, and replacing any disturbed lawn and gravel.

Weston & Sampson engineer Joe Zbell said that tests of sediment samples collected from various locations around the pond found evidence of low levels of contamination by common “urbanized runoff” such as hydrocarbons and volatile organic compounds. The samples also showed low levels of heavy metals and no evidence of PCBs. After discussing options with DPW, it was agreed that the dredged sediment would be carried away for disposal or recycling.

“Specific items such as the management of the sediment have to be outlined in a materials management plan submitted by the contractor, which Weston & Sampson will review and consult with the town regarding the options that the contractor has put forth for the management of those materials,” Zbell said.

Engineer Joe Perugini of Weston & Sampson explained that the Norwalk River Valley Trail, which runs to the west of the pond, will remain open for the duration of the project, but temporary construction fencing will be erected along a portion of the trail to prevent people from entering the site. A portion of the trail will be rerouted along a temporary gravel pathway to allow construction vehicles to use the trail to access the pond. The original trail section will be restored once the dredging work is complete.

Perugini also noted that Connecticut Department of Energy & Environmental Protection (CT DEEP) found no record of endangered species in or around the pond, and determined that the project would have no significant impact from a fisheries standpoint.

The dewatering will be accomplished in three phases: first, a submersible pump will be used to remove most of the water to a holding bladder where it will be filtered and discharged into Comstock Brook; concurrently, sediment attempting to flow back into the pond as the water level decreases will also be pumped out; and finally, sumps will be dug into the bottom of the pond to siphon off below-ground water attempting to seep up into the empty pond. Weston & Sampson anticipates the dewatering will require at least three days to complete before the dredging can begin.

No dredging will be conducted within 30 feet of the dam located at the eastern corner of the pond.

When the dredging is complete, Yield will conduct detailed depth measurements of the pond that can be used as a baseline for assessing sediment buildups in future events.

Can Future Flooding Be Prevented?

Following the presentation by Perugini and Zbell, Commissioner Russell Robbins asked whether there were any actions the town could take to prevent similar flood-related damage to the pond in the future.

Pierce noted that the remediation strategy applies lessons learned from the 2011 floods, which also deposited large quantities of sediment in the pond. Following that previous flooding, Pierce said, the town reinforced the Norwalk River’s west bank to help deflect water from flooding adjacent properties and channel it instead into Comstock Brook.

“But in answer to your question, as we know, water’s going to go where water’s going to go,” Pierce said. “I’ve been here since ’91, and in this [2024] storm, I’ve never seen so much water down there.”

“Unfortunately, I can’t predict the future, but hopefully we won’t be before you in the near future on this,” Pierce added.

Comstock Brook Dredging Scheduled for Late Summer

The pond dredging is the first of two restoration projects scheduled for Merwin Meadows Park to repair damage caused by the 2024 floods. In July or August, DPW will also dredge Comstock Brook to remove roughly 100 cubic yards of sediment on either side of the footbridge connecting the park to the adjacent soccer field.

In addition to dredging the sediment, DPW will install cobblestones along the banks of the brook to prevent erosion and future silt accumulation. Norwalk-based Environmental Land Solutions will replaced disturbed plants with new understory trees and native shrubs. The work will be scheduled for late summer, when there is no flow in the brook.

According to Pierce, FEMA has already reimbursed the town for just under $90,000 of the $119,000 allocated for the project’s design phase.

Following the vote by the commissioners, IWC vice chair Frank Simone praised Perugini and Zbell for their explanations of the work to be done.

“Very good presentation,” Simone said.