Stormwater: Community Amenity

via Planetizen via Smart Growth Online: Seattle gets a hearty "WHOOP WHOOP," as the kids would say, from Lynn Richards as she details how stormwater can become a community amenity. She says:

. . . you see that this neighborhood has additional features that aren't as common. For example, the street trees are surrounded by native grasses. At one café, the tables are arranged around a waterfall that is fed by rain water from the roof and empties into a small pond filled with water-loving plants. The roofs of the higher buildings are partially or entirely covered with grasses and flowers. Buildings are set back three feet from the sidewalk and, every 15 feet, there is a small patch of native grasses fed by downspouts from the roof. The main retail street enters a roundabout, the center of which is a large grassy area filled with wildflowers. While calming traffic and adding to the overall attractiveness of this neighborhood, the roundabout retains and filters stormwater from the surrounding streets. Curb cutouts filled with grasses also serve to calm traffic and absorb and filter stormwater.

Specific to Seattle, Richards highlights a favorite here at OSS 2100: High Point. With a landscape designed in part by SvR Design, Mithun (and others?), High Point is setting precedents around the city. Here is what Richards has to say:

High Point Redevelopment, Seattle, Washington. A new 1,600-unit, mixed-income development will replace 716 subsidized housing units on 120 acres in the West Seattle neighborhood. The site's previous infrastructure directed polluted street, sidewalk, parking area, and building runoff through a series of underground pipes directly into the creek, damaging the ecosystem and reducing local salmon populations. Now, narrow streets, sidewalks, and a traditional grid system make it easier for people to get around the neighborhood while also reducing stormwater runoff through site design. Water-specific strategies are actively incorporated to further mitigate runoff. In place of curbs and gutters, swales and check dams are shaped into the land alongside the street. These wide, landscaped swales buffer pedestrians from traffic, as well as slow, filter, and direct street runoff into a detention pond that doubles as a park area. Parking areas are constructed with pervious gravel cover, and sidewalks with porous pavement. Together with the housing units, these features create a comprehensive system that will cover all 120 acres of the site.