Site Water Management Goes Underground

Designers of a LEED certified office park utilized an existing water vault as a centerpiece of drainage and irrigation.

By Monica Moreira Audette, LEED AP

In Waltham, MA, the 175-185 Wyman Street project features two new Class A office buildings at the foot of the Hobbs Brook Office Park. Designed by Margulies Perruzzi Architects and built by Columbia Construction Company for the developer/owner Hobbs Brook Management LLC, the 175-185 Wyman Street project earned LEED Gold certification, and Innovation in Design credits in all five categories. The project is a case study in thoughtful site preparation and water management.

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Photo: Hobbs Brook Management

Site Selection

The 175-185 Wyman Street project posed very challenging site constraints for the designers. Approximately one-half of the property is located within the watershed of the Cambridge Reservoir, a public drinking water supply. The other half is tributary to an adjacent wetland. Both the reservoir and the wetland ultimately drain to the Lower Basin of the Charles River. The quality of stormwater runoff from this property is critical to regional water supply and resources.

The basic site planning of the project was a positive response to this stormwater challenge. An uncommon component of suburban office developments, parking garages were incorporated under the new buildings. Besides being a convenient amenity, these parking structures are an important aspect of the environmental response because less paved surfaces receiving precipitation mean that less polluted stormwater finds its way into the watershed.

Water Conservation And Management

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Photo: Warren Patterson Photography

Further contributing to environmental protection, a state-of-the-art stormwater quality treatment system was incorporated into the site’s drainage, collecting runoff from the roofs of the new buildings for use as landscape irrigation. A 200,000-gallon underground vault, used previously for fire protection water storage, was retrofitted for use as an irrigation water supply, reducing demand for water from municipal sources. The drainage and treatment system collects and cleans the stormwater and stores it in the underground vault for irrigation purposes. The campus landscape features drought-resistant plant materials, indigenous to the region, which minimizes the need for irrigation water.

All the stormwater that falls on paved surfaces is captured and run through multiple treatment steps. As the first guard of the drainage system, new catch basins are equipped with four-foot sumps to collect large granular sediments and with outlet hoods to trap floatable petroleum pollutants normally associated with pavement runoff. Stormwater is then piped from the catch basins to treatment structures specifically designed to separate finer pollutant-laden sediments from the water before it is released to infiltration structures, recharging groundwater, or released to an attractive six-foot deep pond. The landscape feature pond cleans the water using naturally occurring biological processes before the water is released toward the Cambridge Reservoir. As an added measure, the pond is lined with an impermeable liner to prevent unfiltered water from infiltrating the groundwater.

To complement the mature landscaping existing on the site, the design team created a small waterfall near the pond as a focal point upon entry to the campus.

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Photo: Warren Patterson Photography

Project team:
Owner: Hobbs Brook Management, LLC
Leasing Agent: Wyman Street Advisors
Architect: Margulies Perruzzi Architects
Construction Manager: Columbia Construction Corp.
M/E/P: AHA Consulting Engineers
Landscape architecture, site planning, environmental permitting, and civil engineering: John G. Crowe Associates, Inc.
Geotechnical Engineer: Haley & Aldrich
Transportation Engineer: VHB
Structural Engineer: Goldstein-Milano
Cafeteria Architect: Colburn & Guyette
LEED Consultant: Richard Moore Environmental Consulting
Lighting Design: Lisa Zidel Lighting Design
Elevator Consultant: Lerch Bates & Associates
Specifications Writer: Kalin & Associates, Inc.water management

Moreira Audette is a senior project manager and associate partner at Margulies Perruzzi Architects, an architecture and interior design firm based in Boston, MA.