Stormwater permit for four-lot Mendle Road proposal continued to June 24

The Conservation Commission voted to continue a public hearing on a stormwater permit application for a proposed four-lot subdivision on Mendle Road until its June 24 meeting to allow the applicant to submit revised drainage details and peer-review responses.

The application, filed by members of the Knox family, proposes three retreat lots and a fourth standard lot served largely by a 24-foot-wide common gravel driveway with a paved apron at the entrance. The applicant’s representative said the design relies on a continuous swale, leaching trenches, bioretention basins on two lots and roof-runoff recharge systems on all houses to manage runoff and keep discharges away from the flagged wetlands.

Commission staff and the town’s peer reviewer had a small set of remaining technical items. Deb Keller of Mel Engineers flagged the need for a dimensioned sediment outlet pad along the main swale adjacent to the common driveway and asked for updated spot grades to confirm runoff will reach stone trench drains as intended. The applicant’s team told the commission it could provide revised plans for those details.

Chair members also discussed culvert capacity for a driveway crossing and noted peer review had prompted a change from a single 12-inch pipe to twin 12-inch culverts under a driveway to better handle an upgradient watershed. The commission concluded the outstanding items could be handled by revised plans and conditions and approved a motion to continue the public hearing to June 24 so the full, redrawn plans can be submitted and reviewed.

Next steps: the applicant will supply revised plans addressing the peer-review notes; the commission will consider those revisions at the June 24 meeting and may attach conditions or require a final check by the peer reviewer before issuing the stormwater permit.