Stormwater June 2012 : Page 31
plugs the spaces between the pavers. Approximately 90% of the rain events in the Portland area are low volume and long lasting and are easily handled by the pavers. Excess runoff from the remaining 10% fl ows to a sys-tem of bioswales, all of which are planted with native plants. “If we get a downpour, it’s not going to go between the pavers,” says Keck. “It’s going to run on top to the bioswales in the center of the parking lot.” Runoff from the heaviest rain events fl ows into catch basins and from there to addi-tional bioswales. All the water from the site eventually hits one of two large water-quality swales, where it is treated before it reaches a creek on the western side of the facility. As part of the project, THPRD restored a 50-foot buffer along the creek. “It’s a requirement if there’s any type of wet-land or creek,” he says. “For the length of the project we took out invasives and planted over 1,500 native plants, shrubs, and trees. We also maintain it.” The sports fi elds are multi-use. “When we talk multi-use, we really mean it,” says Keck. “It’s more sustainable for us.” On 11.5 acres of the facility is a grass area with soil en-gineered to hold moisture and therefore require less irriga-tion. With a “fl ipped design,” portable outfi eld fencing, and removable bases, the area can be used as four fi elds for Little League, softball, or baseball. When the fencing is removed, it can be used as three soccer, lacrosse, or football fi elds. The synthetic turf fi elds are used for soccer, lacrosse, and football. Below the 2-inch-high turf is a layer of clean gravel, a layer of fl at drains every 15 feet, another layer of gravel, and a fi lter fabric on the soil base. “If water hits the gravel, it hits the fl at drains,” he says, “and our system dumps it into the water-quality swales.” Large berms on the southern and eastern boundaries of the facility cut down the noise and light as well as pro-vide seating for spectators. They also provide the space for 500 landscape trees, which were selected from the college’s Landscape Technology program plant identifi cation list for its horticultural class. The facility has a number of other amenities, including pic-nic areas and a play area for children. It was funded by system development charges that THPRD collects from developers to help offset the costs of growth within its service area. “It was a great project,” says Keck. “I’m very fortunate to have been part of it.” Sierra Pacifi c Constructors When a high-end commercial general contracting company updates its parking lot, quality is important. “They wanted to stay as green as they could,” says Gerber. J.M. Gerber Construction laid the Aqua Roc permeable paver system from Belgard Hardscapes in Atlanta, GA, in the parking lot. “Belgard offers a large array of stones, styles, and patterns,” he says. “Their colors are very consistent through the stone.” The general contracting company, Sierra Pacifi c Construc-tors in Woodland Hills, CA, has managed projects for such companies as Google, Yahoo, the Oprah Winfrey Network, Los Angeles World Airports, and Aston Martin. In 2011, the company won the Southern California Chap-ter of the International Interior Design Association’s Calibre June 2012 www.stormh2o.com 31