|
|
|---|
Monday, February 18, 2008
Last year, Kevin Robert Perry won an ASLA Professional Award for a truly innovative stormwater management system he designed for the city of Portland, Oregon. Referred to as the “first of its kind anywhere,” Perry's project replaced the city's combined storm/sewer pipe system with a landscaped curb extension carved out of a portion of the street's parking zone.
In other words, instead of using expensive and high maintenance system to funnel urban runoffs to distant, equally expensive and high maintenance treatment facilities and discharge points, they are instead managed on-site with simple, cost-effective, attractive and environmentally sustainable infrastructure.
And here's how it works:
Stormwater runoff from 10,000 square feet of NE Siskiyou Street and neighboring driveways flows downhill along the existing curb until it reaches the 7-foot wide, 50-foot long curb extensions. An 18-inch wide curb cut allows this water to enter each curb extension. Once water is within the landscape area, the water is retained to a depth of 7 inches by a series of checkdams. Depending on the intensity of a rain event, water will cascade from one "cell" to another until plants and soil absorb the runoff or until the curb extensions reach their storage capacity. The landscape system in place infiltrates water at a rate of 3 inches per hour. If a storm is intense enough, water will exit the landscape area through another curb cut at the end of each curb extension and will flow into the existing street inlets. With the new stormwater curb extensions now in place, nearly all of NE Siskiyou’s annual street runoff, estimated at 225,000 gallons, is managed by its landscape system.
And here's the plant list, which unfortunately makes no mention of genetically modified super-phytoremediating neo-plants:
The plants selected for the NE Siskiyou Green Street are primarily Pacific Northwest natives, such as Oregon grape, sword fern, and grooved rush. Adaptable ornamental species such as blue oat grass, boxleaf euonymus, and New Zealand sedge, were also planted because these species are low-maintenance and fit very well in the neighborhood context. All of the selected plant species are low-growing evergreen varieties with varying colors and textures which always provide year-round interest.
This program, of course, required the participation of the local residents to help realize and, once built, maintain it. As it says in the project statement, “the aesthetic appeal and intrigue of the new stormwater facilities creates a community asset that promotes both environmental stewardship and education at the neighborhood level.”
In looking at the pictures and getting glimpses of context, one could mistake that this sort of project can only be successfully implemented in neighborhoods such as NE Siskkiyou Green Street — fairly well-off parts where residents can exert political influence on street renovations or on anything that can affect property values.
But what we find absolutely wonderful about Perry's designs is that they can be applied to economically depressed areas, in inner cities or blighted post-industrial towns, whose local governments find themselves unable to maintain basic infrastructural services.
Either due to a federal administration siphoning away public works money into boyish adventures; an erosion of its tax base as a result of the subprime mortgage crisis; industries closing or moving as demanded by globalization; or even post-oil and post-water realities making current stormwater management practices unsustainable — these same local governments see their public works budget depleted and running in the red, resulting in their neighborhoods taken off the grid.
The expected response of residents would be to move. Some do just that but it's often the case that many would be financially unable and so must then contend with a pestilential landscape of failed sewers, stagnant pools and unappealing vegetation.
It is in this context, we believe, that Perry's designs seem most suited for and are critically needed.
We can even now think of one specific place: East Saint Louis, Illinois.
In any case, Perry also won an ASLA Professional Award the previous year for a similar stormwater project, also for the city of Portland, Oregon.
It definitely deserves a look.
And these before and after photos are worth noting.
So congratulations to Kevin Robert Perry.
Sustainable Stormwater Management Program, Portland, Oregon
Dispatches from a Post-Water Chicago
Grasscrete©
