Wednesday, October 11, 2006
Low-impact methods have high impact on ecosystems
Rain barrels, green roofs play a key role in saving orcas
By LISA STIFFLER AND ROBERT McCLUREP-I REPORTERS
In the front yard of the Ballard house is a hole wider than a bathtub. It has sloping sides and the bottom is lined with shiny ocean-blue rocks. It's planted with native iris and grasses. A drainpipe from the roof at the front of the house empties into it.
An interactive overview of strategies for controlling stormwater runoff from residential homes
Neighbors keep asking Ryan and Kristen Bergsman if it's going to be a fish pond.
At the back of their house is a 480-gallon black plastic tank as big as two fridges tipped on their sides. It's fed by drains from the garage and the house's back roof.
A monstrosity to some, the plastic cistern "is kind of a point of pride for us," Ryan Bergsman said.
Installed last year, the cistern and hole -- actually a "rain garden" -- are tools to control stormwater, holding it where it falls and letting it soak into the earth.
In the nearby Broadview neighborhood, standing at the intersection of Second Avenue Northwest and Northwest 120th Street, looking north what you see is unremarkable: a street with unpaved parking strips on each side.
Look south. It's quite different. The curvy street snakes along, its edges stocked with plants. Where most streets have deep and narrow drainage ditches, this one has a broad, shallow swale filled with grasses, salal, sword ferns and dandelions. Here, water can soak into the ground.
"If you really want to preserve ecosystems, if you want salmon to survive, this is what the science is telling us to do," said Tom Holz, a private consultant and expert on what's called "low-impact development."
The Seattle projects -- which include numerous homes and city blocks -- were paid for and led by Seattle Public Utilities.
"It's a rare approach to an urban watershed," says Heungkook Lim, a University of Washington researcher.
He regularly checks a stormwater measurement device in a ditch on the Broadview road, which is known as the Street Edge Alternative Project, or SEA Street. Since monitoring began in 2000, there's been essentially no runoff. The experiment has been a tremendous success.
When it comes to stormwater, there basically are three options: Keep pollutants out of the stormwater; clean up the water at treatment facilities before it empties into streams and Puget Sound; or do low-impact development to keep the water onsite so it seeps back into the ground.
Many scientists say the most cost-effective, environmentally smart solution -- some would say the only solution -- is the last one.
"We have to trick the environment ... into thinking it's an old-growth forest," said the UW's Richard Horner, a stormwater scientist.
Heungkook Lim, a University of Washington researcher, checks rainfall levels in the Piper's Creek watershed in North Seattle. Lim says a pilot project in the neighborhood has virtually eliminated storm runoff, the fastest-growing source of pollution for Puget Sound. In developed areas, rain runs off impervious surfaces, picking up pesticides and other pollutants, and if unimpeded, carries them to waterways.
In the forest, trees and plants help the soil sponge up the rain. In urban areas, it runs off pavement and roofs, picking up pesticides, vehicle oil and grease, and metals. City rain gardens and grassy swales try to imitate the woods.
But the spread of low-impact strategies has been excruciatingly slow in the Puget Sound area.
Olympia requires developers to use low-impact tools in select cases. Proposed rules for most governments in the Puget Sound basin require them to allow this approach to development, but do not force them to embrace it.
It can be challenging to balance high-density development while maintaining natural spaces to absorb the water. Narrow, planted streets can be difficult for fire trucks to navigate. Porous cement and roofs planted with grasses can cost more to build and require ongoing maintenance. And the approach doesn't look like the developments most people are used to.
Later this month, the state Department of Ecology is awarding $2.5 million in grants to local governments wanting to test low-impact development projects.
The Puget Sound Action Team, a government agency, has published a detailed how-to manual describing these strategies. It has helped 19 cities and counties craft low-impact development regulations, and about a dozen additional governments provide incentives or allowances for low-impact development -- out of 125 regional governments total.
There are other areas of progress. Seattle is expanding its SEA Streets and cistern programs. A light rail system that could help get more cars off roadways is under construction. A federal judge banned the use of pesticides near salmon streams.
But improvements are scarce and resistance to change remains.
"It'll take somewhat of a revolution in planning and regulation and people's thinking and people's willingness to take some chances in doing things differently," Horner said.
P-I reporter Lisa Stiffler can be reached at 206-448-8042 or firstname.lastname@example.org. P-I reporter Robert McClure can be reached at 206-448-8092 or email@example.com.