Civil, environmental, and geotechnical engineering services to redevelop an abandoned rail yard in the City of Concord for a Mixed-Use Development.

This project involved the transformation of an environmentally sensitive and abandoned rail yard known as the South End Rail Yard located on the south side of Langdon Ave in Concord, NH. The property consisted of a roughly 33-acre parcel occupied by the south end marsh, vacant open land, abandoned buildings, and an existing Climbing & Fitness facility. Our work included the design and permitting for a mixed-use development that was comprised of two multi-story commercial office buildings, 200 multi-family residential units located in six 3-story buildings, a clubhouse, and associated parking. We worked closely with the City of Concord staff to obtain conditional use and major site plan approvals. The multi-phased project is slated to start construction in 2022.

challenges

  • The site is located within the City’s Opportunity Corridor in an area that has been impacted by past industrial use as a rail yard for the Boston and Maine railroad.
  • Traffic Study concluded that off-site improvements were necessary for the proposed development. Improvements included the expansion of South Main Street at the intersection with Langdon Ave to provide a left-hand turn lane into the site, pedestrian crosswalks, sidewalks, and the relocation of utility poles.
  • Stormwater control measures were a challenge because of high water table, a significant increase in impervious area, proximity to the South End Marsh, and environmentally impacted “urban” soils underlying the site.

solutions

  • Within the residential development the site was designed such that the environmentally impacted soils were capped with impervious surfaces or 2-feet of clean soils.
  • We worked closely with the City of Concord staff to come up with simple and cost-effective solutions for the off-site improvements within the City’s ROW.
  • We worked closely with the New Hampshire Department of Environmental Services (NHDES) and the New Hampshire Fish and Game Department to implement creative stormwater mitigation solutions using best management practices including; lined stormwater detention ponds, drainage galleries for storage beneath parking lots and treatment of the stormwater runoff to minimize impact to the sensitive South End Marsh.

results

The site development was approved by the City of Concord in 2021. The phased project began construction in 2022.