The level of construction and amenity would surely please civic leaders at the best of times; that this revival has occurred in the midst of a deep global recession makes it pretty remarkable. What is also worth noting is that the development that spurred this, the headquarters of the Bureau of Alcohol, Tobacco, Firearms and Explosives, is a strange concrete melange with all the outward charm of a Cold War military installation. Happily, its gloom is contained, for across N Street NE lies another key development called Constitution Square that signifies the ambition and urban vitality of the area.
This block alone contains 1 million square feet of office and retail space, a 200-room hotel and 440 swanky apartments, with more on the way.
The complex has a contemporary ecological polish — you can check out the Earth-friendly streetscape in the new online guide to green spaces in Washington assembled by the American Society of Landscape Architects, but it is not until you see it yourself that you get a complete sense of its features.
Trini Rodriguez and Dennis Carmichael, whose Alexandria firm, Parker Rodriguez, designed the landscape architecture, agreed to show me how it came together.
Until fairly recently, street trees were planted in impossibly small soil boxes. The roots had inadequate space to grow, the soil became compacted and these forlorn plants had to endure flood, drought, poor nutrition and heat stress. They were lucky to live 10 years.
Here, on the 1200 block of First Street NE, native canopy trees are planted in interlocking subterranean boxes called Silva Cells. These crate-like structures support the street while creating volumes of open soil for roots to wander. “There used to be another technique of using a structural soil,” Carmichael said, “but that fell out of favor because 80 percent of the volume was rock, not soil.” The cells “are expensive but they’re worth it,” he said, “for the health and longevity of the trees.”
A few feet away, the broad sidewalk is defined by a sunken bed planted with amelanchier trees and rushes, which rise out of a gravel mulch. The bed is framed by a raised curb whose gaps receive rainwater from the sidewalk. The planted well also traps hundreds of gallons of storm water from the street and stores and filters it. Some of it percolates into the soil, some evaporates, some is returned — but not before it takes some of the pressure off the District’s combined storm sewers.