The Concord Planning Board voted to approve a minor site plan and associated conditional use permits allowing construction of a detached workshop and single-family dwelling on a mostly wooded parcel on Shaker Road, with several waivers to city site-plan rules and a lot-line adjustment to move the driveway out of the wetland.

The applicant, represented by civil engineer Ian McKim of Jones & Beach Engineers, told the board the roughly 15-acre parcel contains a wetland along the frontage and that the proposal locates the driveway and a detached workshop to avoid direct wetland impacts where possible. McKim said the project will capture and infiltrate impervious runoff from the developed areas into two proposed stormwater ponds and that the design captures “100% of the impervious that’s on our property into these ponds.”

The item mattered for neighbors and staff because engineering found the larger watershed downstream experiences chronic flooding and the board’s site-plan regulations require post-development flows to not exceed predevelopment flows. City staff recommended most requested waivers but recommended denying 1 waiver that would allow increased post‑development peak flows because of documented downstream flooding near Mountain Road and a constrained culvert and downstream pipe.

Board members and staff discussed the tradeoffs: the applicant explained that, because the surrounding watershed and existing vegetation shorten the modeled time of concentration, the applicant’s on-site infiltration cannot, under the modeling standards, fully return modeled peak flows to predevelopment values even though the design retains and infiltrates runoff from all on-site impervious surfaces. A majority of planning board members accepted that explanation and found the applicant had minimized impacts through the lot-line adjustment with the adjacent owner (Lot 68 Shaker Road), revised driveway routing and the proposed stormwater ponds.

The board granted the requested waivers, approved the conditional use permits to allow the disturbance of wetland buffers (the staff report noted a permanent impact of 4,550 square feet of wetland buffer for driveway and utility access), and granted site‑plan approval subject to precedent and subsequent conditions listed in the staff packet (standard engineering review comments, recorded easements for the shared driveway, and construction‑phase stormwater controls). The board also approved a related minor subdivision/lot‑line adjustment that provides the additional frontage needed to place the driveway outside the wetland buffer.

Board members and the applicant noted the property will be served by a well and septic system, underground power along the driveway, and that parking needs are minimal for the proposed one‑person home‑based business. The planning board recorded its findings and closed the public hearing before approving the motions.