We usually think of Bay Area cities as green. Many have outlawed city-sponsored spraying of pesticides and herbicides, and most encourage recycling, help residents plant street trees, and engage in a host of other hopeful acts that benefit water quality in our creeks, rivers, and bay—our watershed. Several cities are daylighting and restoring their creeks, thanks to a huge grassroots-led movement during the past couple decades.
But after visiting Portland recently, I’ve been wondering if we’re green—or blue—enough.
Portland’s Willamette and Columbia rivers are home to several endangered and threatened species of fish. Like all cities throughout the country, Portland is subject to a myriad of federal laws regulating stormwater and urban runoff—the Clean Water Act, Endangered Species Act, and the National Pollutant Discharge Elimination System, to name a few. But what Portland is doing differently is seizing every opportunity to retrofit its old concrete and asphalt hardscape with ecoroofs, “green” streets and parking lots, bioswales, stormwater planters, “rain” gardens, and even a “stormwater wall,” all with the goal of capturing and filtering urban runoff before it flows into the rivers.
Linda Dobson, program manager for the city’s sustainable stormwater team, enumerates the problems caused by unrestrained urban runoff. “Whenever it rains, stormwater that isn’t properly managed races over streets, rooftops, parking lots, and other impervious surfaces picking up oils, dirt, chemicals, and other pollutants,” she says. Those pollutants get carried into streams and rivers, an unhealthy diet for fish and other critters.
The old way of moving stormwater was to get it out of sight, out of mind as fast as possible—via pipes and other “hard” infrastructure, says Dobson. But Portland is making its stormwater visible—and even pleasing to the eye. “Green streets” have stormwater “planters”—mini wetland gardens set below grade between the sidewalk and street—into which runoff from the street flows via cuts in the curbs. There, the water can collect (as it would in a pond) and be filtered slowly by plants before infiltrating the ground. Local businesses, supported by small grants from the city, have come on board. New Seasons Market on Division Street, one of the newly targeted “green streets” in southeast Portland, uses a series of inter- connected stormwater swales around its perimeter to collect runoff from the roof, outdoor plaza, and parking lot. Rain from one downspout pours onto a quirky metal sculpture before filtering into a stormwater planter. Ninety percent of the average annual rainfall the site receives is captured.
The only stormwater innovation New Seasons doesn’t have is an ecoroof, but lots of Portland’s buildings do. Tom Liptan, environmental specialist with the city, and self-described “stormwater geek,” is busy unpaving roofs. He put an ecoroof—what he calls a “living roof”—on his own garage in 1996 and has been the impetus behind the city’s dozens of stormwater planters and at least 30 green roofs throughout the city. An ecoroof differs from a more formal rooftop garden in that it is covered with a fairly thin layer of soil (versus container planting in boxes). Using drought-tolerant, low-maintenance plants, Liptan describes it as its own ecosystem, with the soil microbes treating urban pollutants and the plants attracting bugs and birds.
On a tour of downtown Portland, Liptan showed me more opportunities for retrofitting the built landscape with natural systems. These solutions don’t have to be big. A six-foot-square stormwater planter between a parking garage and a school filled with wetland plants filter out the bad stuff that would normally end up in the Willamette River. We visit Montgomery Street, which will soon become a “green street,” landscaped with slightly below-grade planters in the curb strip.
We stop to examine an ecoroof atop a public housing project. Liptan has monitored the roof for three years and found that 60 percent of even a large storm, one that drops over three inches of rain, is absorbed by the roof, and some evaporates. “The air is the infrastructure!” he tells me as we walk the rooftop. He stops to investigate insects hovering over a wildflower. “The roof reduces the amount of stormwater the municipality has to treat or manage. It reduces wear and tear on the system,” he says. “Ecoroofs are the best stormwater detention facilities you can buy. They retain all sizes of storm events whereas stormwater vaults and even ponds only retain certain sized storms.”
For those not quite as keen on ecoroofs, like developer Ed McNamara, principal of Turtle Island Development, there are other alternatives. McNamara built two apartment buildings—144 and 122 units—as a redevelopment project in a blighted area of town. To deal with stormwater, he and Liptan and other city stormwater staff came up with the idea of installing formally landscaped planters into the central courtyard. Looking at the planters, installed somewhat below grade, you might not guess that they are runoff treatment systems. On the second building, McNamara used more stormwater planters and a couple of small ecoroofs. “None of it was permitted by code at the time,” says McNamara. “But it all made sense.” McNamara recalls thinking that if this was the future of stormwater management, he wanted to be part of it.
In contrast, developers in the Bay Area have fought new, more stringent NPDES stormwater regulations. Builders of all new developments of over one acre in the Bay Area are required to treat stormwater on site—but that number was “negotiated” up from the original requirement of 5,000 square feet, according to Jan O’Hara with the S.F. Bay Regional Water Quality Control Board. In 2006, the requirement will be lowered to 10,000 square feet; the same number applies to redevelopment sites. The Water Board’s Keith Lichten says that many of the large new developments (which tend to be those sprawling out beyond built-out urban areas) do include onsite stormwater treatment. But the large size requirements—10,000 square feet—make it less likely that redeveloped sites in the Bay Area will see the kind of innovations Portland has made.
Part of Portland’s success is due to the fact that, over the past several years, it has acted aggressively to win over $1.5 million in grants from the EPA for innovative stormwater projects. The city also mounted an impressive public awareness campaign using demonstration projects at schools, commercial buildings and parking lots, and on residential streets. Several neighborhoods are now on a waiting list to have stormwater curb extensions—small areas that extend out from the curb and are planted with wetland plants— installed on their streets. And over 38,000 homeowners have disconnected their roof downspouts from the stormwater system, redirecting them into gardens, swales, planters, or cisterns. (The city reimburses homeowners for the disconnection or will do the work for them.)
Disconnecting, says Dobson, has removed over 768 million gallons of roof water each year from the storm drain system. The downspout disconnect program, she says, is a kind of metaphor for the rest of Portland’s stormwater efforts. “Whether you’re disconnecting downspouts or disconnecting impervious surfaces from the pipe system, it’s the same idea,” she says. But perhaps most importantly, Portland has learned to view itself through a watershed lens. That, says Dobson, means that in addition to restoring a stream, they look at problems upstream, which often contributed to downstream degradation. “I think there is no one silver bullet,” says Dobson, when I ask her which stormwater solutions have been most successful. “We want to try all those things—planting large canopy trees, getting ecoroofs to intercept the rainwater. Then as it hits the surface, we’ll intercept it wherever we can—with green streets, rain gardens, stormwater plants, swales, etc.”
Here at home, things are not looking as green, and, according to Water Board regulators, the development community is resisting new approaches to treating stormwater. There are a few signs of hope. The San Francisquito Watershed Council is planning to build two demonstration projects—one treating a commercial parking lot and another retrofitting a residence in Palo Alto—this year. And a neighborhood group in San Francisco’s Mission District jackhammered up the concrete public right-of-way along their street and planted gardens with the goal of creating more permeable surface. Perhaps—just as in the creek movement—citizens need to lead the way.
