Project Context and Design Challenges
The project site was a former industrial site for Sylvania in need of extreme remediation. Trees that had been planted at an earlier adjacent residential project had either died or failed to grow much. Through soils testing, discussions with maintenance staff & consultation with an arborist it was discovered that the site’s soils, once under the factory floor, had been compacted to the point of impermeability (a soil boring drill bit actually broke during sampling). The soil was biologically dead with only scant traces of organic matter and unable to support plant life of any kind. In addition, despite the existence of a traditional subsurface storm water system that emptied directly into the marsh, the flat site had drainage issues, which were also decreasing the quality of the soils. The tidal marsh itself, was an untapped resource with the potential to offer recreational opportunities including exceptional bird watching, but existing Atlantic Hall largely hid it from the rest of the campus.
This campus had traditionally been a largely commuter campus and the landscape had developed around accommodating the car. The landscape architect worked closely with the client & architect from the beginning, looking at alternative ways to organize the building that would create high quality outdoor spaces that could bring unity to a disjointed commuter campus, connect pedestrians to the tidal marsh and create a more sensitive approach to stormwater. This portion of campus has minimal open space and the client wanted to establish a more traditional campus development pattern. The resulting “Z-shaped” residence hall forms two new courtyards, connected by a 2-story outdoor portal that frames views of the tidal marsh to the south.The site design is organized along a strong central spine, an exposed aggregate walkway that orients the courtyards to the marsh. A seldom-used vehicular drop-off was eliminated at the front of the site to create the northern “campus green” courtyard which serves as a gathering space and the main entry to the hall and cafeteria. An existing landform from the industrial past of the site was retained but intersected by a long, board-formed concrete seat wall that directs pedestrians to the building entrances. The southern “marsh courtyard” features a tilted lawn open space for recreation and a 180’ long bio-swale that collects the site’s storm water and extends in a straight line toward the marsh. A phase two walkway extension will terminate at an overlook at the marsh edge (due to permitting requirements and the aggressive schedule of the residence hall, the overlook was postponed to the second phase of the project, slated to begin in 2012).
The soil in the central courtyard space was augmented, aerated, and graded to create a tilted lawn plane. This improves overland drainage, breaks up soil compaction, provides an open play area, and adds visual interest to what used to be an extremely flat site. Nearly 10% of the $1.8 million landscape budget was spent on site remediation. Storm water from both courtyards, 41,000 square feet of roof area, and adjacent plazas flows into a linear bio-swale which is which is filled with native grasses, rushes, and perennials. Here silt and contaminants are filtered out and most of the storm water infiltrates back into the ground. What doesn’t infiltrate is slowly released into the tidal marsh. The bio-swale is lined with stone-filled gabions on one side, evoking the feel of a wharf, an appropriate reference for historic “seafaring” Salem. The tilted lawn forms the opposite side, providing extra holding capacity in unusually large rain events. This was tested shortly after construction completion when Salem experienced a massive rain storm. The water extended 20’ into the tilted lawn but had completely receded to the bio-swale one hour later. The gabion system, with its Ipe stadium seating and gangplank bridges, also gives an architectural expression to a natural process and allows for informal gathering in the midst of natural storm water management. LED lighting is concealed underneath the gangplanks, illuminating the bio-swale at night. In addition, a 6,200 square foot sedum green roof extends over the lower level dining hall, lending a green foreground view from the dorm rooms above, slowing the storm water flow and providing additional environmental and building operations benefits. The sedums are arranged by variety in architectural bands separated by beach pebble runnels. The bands align with the paving geometry on the ground, creating a strong correlation when viewed from the residential rooms above. As the sedum varieties migrate over time the bands will become less graphic demonstrating the process of plant naturalization and colonization.
This project combines and highlights soil remediation and storm water management in a central campus environment with everyday use by college students. Marsh Hall shows that these two seemingly opposite goals can coexist. The formal, contextually appropriate character of the walls, seating areas, and gangplank bridges encourages student use, while the careful study and augmentation of the soil and the creation of the bio-swale allow for a healthier campus and adjacent tidal marsh. Most critical, though, is the fact that hundreds of students will interact, on a daily basis, with a natural storm water system. This will undoubtedly make them more aware and accepting of this innovative, environmentally beneficial technology.