A proposal from Stoss Landscape Urbanism and SHoP is the preferred solution to connecting downtown Dallas with the Trinity River. The plan calls for compact urban neighborhoods surrounded by forested landscapes. Stoss + SHoP
A design competition imagines a vibrant mix of urban districts and landscaped spaces for the banks of the Trinity River.
April 8, 2014—The Kessler Plan, which guided growth in Dallas during the early decades of the 20th century, called for moving the Trinity River half a mile from its original location and building a parallel levy system alongside it. The levy system was originally built in 1932 and was placed beyond the old river. Meanders that were part of the original riverbed, and are now referred to as sumps, still remain and are used as part of the city’s stormwater management systems. Water flows into these meanders and is then pumped through the levy into the floodway.
The river and the floodplain that separates it from downtown are utilitarian places—important for moving stormwater and cars but hardly places that would appeal to the public. But that is gradually changing. While efforts to transform the Trinity River into a recreational oasis have been ongoing for years, a recently concluded design competition aims to revitalize the land between the river and downtown Dallas, a 500-acre tangle of parking lots, floodwater zones, and extensive freeway infrastructure. The Connected City Design Challenge aims to re-create that land as a vibrant urban and recreational district. The challenge was sponsored by a variety of urban stakeholders, chief among them the Dallas CityDesign Studio, an urban design office run by the city, and The Trinity Trust Foundation, a nonprofit that is spearheading efforts to transform a 20 mi stretch of river into a showcase public space.
“The challenge has reminded us of this potential and given us a way to make it happen,” says Brent Brown, AIA, the director of the Dallas CityDesign Studio.
The competition drew entries in both a professional and nonprofessional division. Among the three professional finalists were Ricardo Bofill Taller de Arquitectura, a Spanish firm; Rem Koolhaas’s Rotterdam-based firm, OMA, and OMA’s think tank, AMO. Brown says there was a great deal of debate among the jury about whether to select a winner; it ultimately decided not, concluding that all three finalists offered compelling ideas. However, Brown notes that a proposal put forth by the Boston-based design firm Stoss Landscape Urbanism and New York-based architecture firm SHoP, called HyperDensity/HyperLandscape, was the “preferred submission because of its completeness, and because of the overarching strategy of bringing the city together.”
Sandwiched between two bridges, the Viaduct neighborhood
could contain large-scale spaces such as a technology campus
or a mall. Stoss + SHoP
The site is large and complicated, sandwiched between the river and the city, and crisscrossed by a web of freeways. Getting through this underutilized area, as one as one observer put it, makes for an unpleasant walk. “It’s really difficult to handle,” says Amy Whitesides, an associate with Stoss Landscape Urbanism. The firms quickly realized that their solution wouldn’t be to fully develop the entire site but instead to find a solution that relied on landscape architecture for some spaces and constructed development in locations where that would be most effective. “Where it would be incredibly difficult for buildings to integrate into a lot of the highway infrastructure between the river and the city, except in a few places, landscape can do that much more easily,” says Whitesides. “It can be utilized in areas that pose technical, social, or economic barriers to development.
“Weaving development in and out of the extensive highway system is not likely to create quality neighborhoods that will draw people to living in and around downtown,” she continues. “Instead, we used the forest to thread between the highways and placed development where it could create high-quality neighborhoods that linked existing neighborhoods or districts to the Trinity River.”
The plan calls for three development areas. The northernmost zone, called DECCO, for Design Crosses Commerce, is named both for the city’s so-called design district and for Commerce Avenue, which cuts through the zone. Not far from Dealey Plaza, DECCO would both extend the city’s design district and pull downtown closer to the river.
The central zone, dubbed the Viaduct, is placed where two existing viaducts span the river, linking downtown to the city’s Oak Cliff neighborhood. The designers envision a technology campus or mall, larger-scale commercial development, and mixed retail and residential development for this area, which is situated near hotels and a convention center.
The southernmost zone, called Riverfront South, is planned as an extension of lower-density mixed-use residential developments located at the south of the site, where a maritime museum housing the USS Dallas submarine is being planned.
The different zones of the proposal could be linked by bike lanes or a trolley system that could eventually be converted to a light-rail line.
The southernmost zone, Riverfront South, is planned as an
extension of the lower-density, mixed-use residential areas on the
south side of the site. Stoss + SHoP
The landscaped areas in between are planned to function as hydrological systems in some places, and simple forests in others. Part of the landscaping “will be managing some of the hydrological issues,” says Whitesides. “Some of it, especially right along the highways, will be a more permanent feature, hugging the highway and making it a more pleasant driving experience and acting as sound barrier for adjacent development.” Other areas may become nurseries; others might incorporate as a forested BMX bike track that takes advantage of the highway infrastructure, a playground, or even an ‘art forest’ housing large sculptures that can’t be accommodated within the existing arts district.
By developing the forested area as a buffer to the highways, the team is “essentially creating a greenway and making the experience of the highway better,” says Whitesides. “Also, you do something to offset the carbon production of cars moving there daily. It’s unlikely Dallas will stop being a car culture in the near future. We accepted that and began our process by thinking about how we might improve conditions and also build some new developments that are walkable and served by transit.”
Each of the neighborhoods is centered on a water-based amenity that recognizes the historic path of the Trinity while providing quality recreational space. At DECCO, an urban beach spans the space between the levee and the new development. A wooden promenade extends from the beach outward, and over the levee to provide a kind of observation deck from which one can take in both the city and the river, easily accessing either. From here the promenade continues inside the levee to the Viaduct neighborhood where it meets the “Pump House Amphitheater,” a floating performance space situated between the bridges of the viaducts and the existing pump that moves storm water from the city side of the levee into the river.
Linking each of these amenities is an enhanced storm-water collection and cleaning system that utilizes and expands upon the current storm-water management system.
At Riverfront South the cleansed water becomes a public amenity as it moves through a series of gardens that are both fed by the water and continue to purify it. These gardens house cafes and music venues while creating a lush habitat for birds, butterflies, and people hoping to relax in the cool shade on a hot summer day.
To enhance the storm water system, environmental engineering firm LimnoTech, a consultant based in Ann Arbor, Michigan, that worked with Stoss on its proposals, suggested creating a secondary flow channel to supplement the channel that carries stormwater to the levy and ultimately into the river. In the future, water would be collected in a stone and cobble detention basin, in which the speed of the flow could be reduced and solids settled. A portion of that water could be diverted down a slower-moving, secondary flow channel from which it could pass through pedestrian-oriented structured wetlands.
“Our thought was to complement [the Trinity River Corridor Project] by improving the quality of the water that would pass through this area outside the levy,” says Tim Dekker, Ph.D., P.E., a senior engineer with LimnoTech. Dekker says the conceptual ideas still have to be reconciled with the needs of the U.S. Army Corps of Engineers, but initial modeling suggests that the proposal will retain all the conveyance capacity of current flows, as well as additional capacity to store flows during major storms. “We think it’s going to meet the objectives of the Corps and be a better looking and better functioning natural system as well,” he says.
Now that the competition is over, Brown’s office is working with primary landowners in the area to move the ideas forward. The complexities of sites like the one in Dallas suggest that landscape architects will continue to be as integral to city making as are engineers and architects. “The role and significance of landscape architecture is changing, partly because as a society the challenges we’re facing are more like those in Dallas,” says Whitesides. “These challenges require large-scale thinking and diverse sets of expertise. Landscape architects think across scales and are able to forge interesting partnerships that foster different ways of thinking.”