Planning board accepts subdivision conditions amid dispute over 50‑year runoff standards

The Town of Warner Planning Board voted to acknowledge that conditions for the subdivision of Tax Map 7, Lots 39 and 391 have been met after a lengthy technical debate over stormwater standards.

The board's decision came after engineers and board members debated whether the project complies only with state Alteration of Terrain (AOT) and New Hampshire Department of Environmental Services (DES) rules for peak runoff (cubic feet per second) or whether Warner's site‑plan condition — written to prevent increased runoff or velocity onto adjacent properties — also requires meeting a 50‑year storm volume metric favored by the board's consultant, Ares.

"Because we've met those requirements, Alteration of Terrain has issued the permit. We are in compliance with the rules," the project's presenter said, arguing the design met the state's required peak‑rate metrics and DES review. Several board members countered that the project's retention/detention pond concentrated runoff in ways that could affect an abutter and that the board's condition language remains broader than state guidance.

Board members pressed for clarity on documentation: septic approvals and well locations were attached to the packet, and an as‑built driveway plan must be provided to the planning board and fire department prior to occupancy, as the board's conditions require. The presenter noted the plans had been permitted by AOT and DOT for drainage and that state reviewers had issued permits after review.

During discussion members also reviewed an estimated reclamation bond and the engineer's calculations for pre‑ to post‑development peak rates and volume. One presenter described the bond calculation method as DOT unit‑pricing based and said the estimate had been prepared for board review; the record included references to earthwork quantities in the several‑thousand‑cubic‑yard range.

After debate over the meaning and scope of the condition (whether it required both peak‑rate mitigation and a 50‑year volume match), a motion that the conditions had been met was moved and seconded and carried on a roll‑call vote.

The board directed staff to obtain the signed mylar and complete recording steps. Members discussed next steps for follow‑up inspections and noted the town will require an as‑built driveway submission before any certificate of occupancy (or equivalent) is finalized.

The board did not change its written condition at the meeting; several members said the town may need clearer, more specific language in future site‑plan conditions so the standard to be met is explicit.

What happens next: signatures, the mylar for recording, and submission of required as‑built documents and maintenance arrangements for stormwater features were the practical next steps noted by the board.