The projects installed in the Shattuck Hall Ecological Learning Plaza, Portland State University's brand-new outdoor laboratory, include innovative technologies: a green roof, vertical growing systems (or "living walls"), demonstration landscapes featuring drought-tolerant plants, and seating designed by students in the Department of Architecture--projects that possibly point to the future of architecture, building systems, and landscape design.
But beneath all of this innovation, the Shattuck Hall Ecological Learning Plaza is paved with Portland's past: 30,000 pounds of basalt cobblestones that, in a former life, made up the streets of our city.
You've seen them, still embedded in the pavement of Old Town and the industrial neighborhoods of inner Southeast Portland--reminders of the city's younger days, when horse-drawn carriages and trolleys were the main forms of transport. Time marched on, and as automobiles eventually replaced horses on city streets, so too were the cobblestones replaced, by the new, modern material known as asphalt. So the cobblestones of the city's youthful days were dug up, buried in a St. John's park and seemingly forgotten. But, fortunately, the stones were not fated to stay buried.
A Permeable Base
Conceived as a testing space for, among other things, water runoff solutions, the Shattuck Hall Ecological Learning Plaza had an unfortunate foundation--a solid, impermeable concrete slab that had formed the base of a Campus Public Safety structure, which occupied the site for years. When the structure was removed, Department of Architecture faculty member Jeff Schnabel created a plan to remove much of the existing concrete slab to create a pervious paving surface, intended to allow rainfall to percolate through the paving and gravel and eventually recharge the aquifer. Four large rectangles were removed from the slab to allow for the installation of permeable pavers.
The next step was to find a workable paving solution. In keeping with the Department of Architecture's focus on sustainability and reuse, Schnabel negotiated with Portland Parks and Recreation to essentially loan the historic cobblestone pavers to PSU for the Shattuck Hall Ecological Learning Plaza, on the condition that they would be returned to the city if not in use.
Teams of students braved the winter rains and dug up the cobblestones from their St. John's resting place, loaded them onto rented trucks and transported them back to PSU for unloading and installation in the Plaza.
Meanwhile, another team of volunteers prepared the site by raking away debris, removing small rocks and leveling the earth.
Next, students began the long, painstaking process of laying the stones on the soil, placing each approximately 1 1/2 inches apart. Once the stones were in place, limestone gravel was poured over top and raked into the cracks between the stones until a solid surface was created.
These cobblestones, estimated to be at least 100 years old and part of the historic fabric of our city, now form a beautiful new paving surface--both honoring the region's past and inspiring new ideas for the future.