ZBA approves 140-space parking expansion at 147 Daniel Webster Hwy despite wetland impacts

The Nashua Zoning Board of Adjustment approved a special exception on Feb. 10 allowing Rosscommon Investments LLC to expand parking by 140 spaces at 147 Daniel Webster Highway in the GB zone, a project that will permanently impact wetlands in order to improve on-site stormwater control and remove degraded wetland features.

Engineer Paul Chisholm (Keach Nordstrom Associates) summarized the project background and permitting: the site has a history back to 2019 of trying to find additional storage for vehicles, and the design included coordination with the DOT and the New Hampshire DES. Chisholm said the wetland in question is low-function, largely the result of highway drainage, and that the property would install underground treatment and detention to reduce untreated runoff. He told the board the permanent wetland impact shown on the plan is approximately 22,450 square feet and that DES required a payment in lieu of on the order of $171,000 to be applied within the same watershed.

Board members asked technical questions about how DOT drainage and on-site treatment would be linked. The applicant explained the DOT pipes would remain separate but the new design would collect on-site runoff for compliance with current standards and add an additional layer of treatment before water reaches downstream systems.

Several board members noted discomfort with reducing wetlands in general but said this case involves a degraded, drainage-formed wetland and results in a net stormwater-management improvement. The board moved and approved the special exception; the motion passed and the transcript records "Motion passes."