Commission approves house addition with 2:1 wetland mitigation and invasive control condition

The Town Conservation Commission voted Sept. 18 to close the hearing and issue an order of conditions for a 196-square-foot addition to an existing single-family home at 59 Sylvester Road, contingent on receipt of a revised plan showing expanded plantings. The property owner is William Ryan; Ward Smith of Wendell Wetland Services represented the applicant.

Ward Smith told the commission the addition (14 by 14 feet) with an entry landing and steps places roughly half of the new footprint within the 50-foot no-disturb buffer that borders a beaver-impounded section of Parsons Brook. Because the work occurs in an existing lawn area that the applicant and staff characterized as a degraded or previously filled area, the commission accepted a mitigation approach requiring two square feet of mitigation for every one square foot of buffer disturbance.

The applicant agreed to provide a 5-foot-wide planting strip approximately 76 feet long along the top of the lawn edge, which the parties calculated will yield 380 square feet of mitigation (2:1 for roughly 190 square feet in the buffer). The planting palette will consist of native shrubs already shown on the plan (shadbush, black chokeberry, American hazelnut, silky dogwood) with quantities doubled from the initial submission. Commissioners said the strip will help keep people off the slope and allow the embankment to revert to more natural conditions.

Commissioners asked that invasive species in the new planting area be controlled on an ongoing basis. Commissioner Melissa suggested annual inspection and removal of invasives; the commission adopted an additional order condition requiring annual invasive-species inspection and removal for the mitigation area. The applicant agreed to supply a revised plan showing the expanded planting area and revised planting counts; staff will prepare the order of conditions and mail it to the applicant once the corrected plan is received.

The commission noted the change is expected to improve a degraded area behind the house and that the proposal does not encroach on the riverfront or the submerged channel; Smith said he delineated the mean annual high-water line at the beaver dam and that the work is on the beaver pond side of that feature.

The commission’s vote to close the hearing and issue the order of conditions was unanimous.