Moultonborough Planning Board conditionally approves site plan for 525 Whittier Highway

The Moultonborough Planning Board voted 6-0 on May 27 to conditionally approve a site-plan application for a new mixed-use building and associated improvements at 525 Whittier Highway (Tax Map 103, Lot 10).

The decision followed a presentation by applicant agent Dari Sassan of Brown Engineering and a technical review from stormwater engineer Steve Keach of Keach Nordstrom Associates. In his review, Keach said that "post-development peak flow and overall discharge volumes to Whittier Highway will not increase" for a 50-year storm if the proposed detention basin and other drainage measures are built as designed. He also requested a final sign-off letter from his office after the design is coordinated with DOT District 3.

Board members and nearby property owners pressed on drainage and construction impacts. Board member Sandra Kelly described walking the site during heavy rain and asked whether additional controls such as infiltration trenches, check dams or a rain garden should be added. Engineer Keach replied the basin is a detention facility—relying on controlled outlet and volume storage rather than ground infiltration—and noted the basin has a maximum storage capacity of 4,334 cubic feet for a 50-year event. The applicant and engineer said paved surfaces and swales are intended to direct stormwater east toward Route 25 and that the design intercepts runoff from roughly 3.1 acres (the 0.97-acre parcel plus about 2.1 upstream acres) to avoid increasing peak flows at the roadway despite about 6,300 square feet of new impervious surface.

Abutter Brett Balise said the existing roadside drainage in front of his building is blocked and that he has repeatedly had to clear the pipe by hand; he asked that any approval include protections for abutters. Abutter Norman Poitras, owner of a house built in 1760 at 518 Whittier Highway, raised concerns about blasting and whether he had been notified; applicant agent Sassan said blasting activities were put on hold and that required notifications would be made. Planning staff directed that conditions should require documentation that all property owners within the 100-foot regulatory blasting radius plus an additional 150-foot courtesy zone be included in any pre-blast structural survey and notification.

The board's conditional approval includes a set of conditions precedent to signature and conditions subsequent to be maintained in perpetuity. Key requirements include: identification on the final plan of all federal, state and local approvals by approval date and permit number; a state commercial driveway permit and coordination with DOT District 3 to address any channeling along the 150-foot road frontage; DES septic approval and holding-tank registration for the proposed 10-by-20-foot underground wash-bay holding tank; a stormwater concurrence letter from Keach Nordstrom Associates confirming final drainage design after DOT coordination; provision of financial security acceptable to the Town Planner to ensure erosion controls and third-party inspections and testing; and annual stormwater inspection reports to the Land Use Office on or before July 1 each year. The board also required that approved commercial uses not commence and no certificate of occupancy be issued until all improvements are installed and operationally approved.

Planning staff and the third-party engineer will need to complete outstanding items before the Planning Board Chair signs the final plans. The approval expires on May 27, 2029, unless the applicant acts substantially on the approval, and the applicant may seek a one-year extension before lapse.

The board's motion to approve was made by Kevin Quinlan, seconded by Brendan Connolly, and passed 6-0. The public hearing closed at approximately 8:45 p.m.