Stormwater runoff: an impermeable problem
Our built environment has forced the ecosystem to accommodate precipitation in high and fast volumes. The rush of water from pavement and compacted landscape destroys the natural order. It's also a huge source of Puget Sound pollution.
It's raining again. Rainwater collects in the hollows of red geranium petals, puddles in the low spots of paved streets and plowed fields. In the country, a stream swollen with runoff flows deeper than it did a day before, foaming where it had barely rippled, its water tinged with brown from a tea of old alder leaves but still clear enough to reveal every rock in its bed. In town, water runs over scraps of paper stuck fast to the pavement, laps the edges of an old plastic lid, while raindrops pock the surfaces of dark puddles. Nearby, a comet of iridescence, a great, prismatic, glistening blob with curving tail, adorns the cracked concrete of a gas station. An hour later the comet is gone, its iridescence moving inexorably toward Puget Sound.
Not surprisingly, surface runoff turns out to be the main source of toxic chemicals in the Sound. ("Runoff called top pollutant in the Sound," screamed the Seattle Post-Intelligencer's lead headline on Saturday, Dec. 1.)
This isn't exactly startling news. In fact, it isn't news at all. Stormwater is the main source of water pollution in Puget Sound, writes John Lombard in his 2006 book, Saving Puget Sound. Stormwater "also affects water quantity, dramatically increasing peak flows and the 'flashiness' of streams ... and decreasing base flows during dry periods." By screwing up the natural flow pattern, it alters the populations and species of plants and critters living in the streams. By flowing off the land in fierce torrents, it gouges out stream beds. And it's expensive. Flooding and landslides like the ones we've seen throughout the Northwest this week cost millions every year. Then there's the cost of trying to control and decontaminate stormwater. "The region probably spends more than $1 billion each year to meet stormwater requirements," Lombard writes.
A 2006 report on "Damages and Costs of Stormwater Runoff in the Puget Sound Region" [160K PDF], prepared by geologist Derek Booth and two University of Washington colleagues, found that "[a]nnual stormwater program budgets ... range from hundreds of thousands to millions of dollars, with typical annual costs of approximately $100/person within a stormwater utility district." Booth and his colleagues reported that the city of Bellingham "has estimated $300,000-$500,000/year in additional funds would be required to keep up with current technologies and population growth beyond the $4.8 million currently budgeted. On a larger scale, Snohomish County identified 220 recommended projects with a total project cost of $85 million (representing a per capita expense of about $130)."
But we're not doing enough. In a generally upbeat conversation about restoring Puget Sound, Gov. Chris Gregoire conceded last spring that "where we're not making good progress is in areas like stormwater." UW professor of earth and space sciences David R. Montgomery wrote in the Seattle Post Intelligencer last March that he was "thrilled to see the rollout of Gov. Chris Gregoire's new 'science-based' Partnership for Puget Sound – until I read beyond the executive summary." Reading further, Montgomery found that "buried on page 43 of Appendix A, was a startling admission by the partnership's own scientific working group: 'The strategies listed are not likely to be sufficient to achieve ecosystem goals.' ... [T]here it is in black and white," Montgomery wrote. "The plan won't work." He went on to criticize "[r]eliance on standards in a storm water runoff manual which itself states 'land development as practiced today is incompatible with the achievement of sustainable ecosystems.'" Last year, he was one of 14 scientists who signed a letter to the partnership arguing that the existing plan wasn't likely to get the job done. He subsequently explained that if clean water laws were actually enforced, the current system would probably deal well enough with pollution – but pollution doesn't pose the main threat to salmon or to the natural systems on which salmon rely. Our fixation on pollution helps mask the real problem: a hydrologic pattern in which rainfall runs off across the paved surface of the land, instead of soaking into soil, then making its way slowly to rivers and streams. In an undisturbed catchment, Derek Booth explains, stormwater can stay in the soil for weeks, or even months. Most of the expensive retention ponds required for new development are designed to hold water for only a day or two. "One is led really inexorably toward ways of storing water in the soil," Booth maintains. Step one may be to "make sure there's still enough of that soil column to store the water. We only make it harder when our development style is to strip the land," he says.
Montgomery said he was "kind of mystified as to why anyone thinks that what we've been doing in the past works." No one did, of course, but no one had any plans for radical change.
In June, another scientist who signed the letter, Tom Holz, said he had heard that the missive "shook the partnership to its core. Partnership staff heard most of the ideas at [a] May 2006 workshop, but they chose to ignore them (or more accurately lose them in their Byzantine process for assessing input). It must have been very inconvenient to have them pop up again. ... Our first encounter with the new partnership ... tells us that they are now either intentionally ignoring the 14-scientist letter (my belief) or are totally clueless (belief of some of the other of the 14). They wish, it seems, to make the default option of the further decline of the Sound without the nasty business of having to say that is what they are doing."
Holz has changed his mind. After Thanksgiving, he said that was "the way I felt all the way up until last week, when I met with [new partnership executive director] David Dicks. He's quite a breath of fresh air." After his conversation with Dicks, Holz says that his June comments "are no longer valid." Rather, "the partnership has demonstrated to my satisfaction that they are not going to hang with the recommendations that came out October 2006." Dicks "is sincere about real change."
Holz recognizes, though, that even with Dicks on board, "it's not going to be a slam dunk." The 14 scientists called for, among other things, a commitment to "low impact development," which might involve green roofs, permeable concrete, minimal disturbance of vegetation, and other steps to preserve - or re-create - a relatively natural pattern of flow. Low-impact development "is such a small step and such an easy thing to do," Holz told the P-I, "why wouldn't we do it as quickly as possible?" The partnership has called only for low impact demonstration projects. "You don't have to be a scientist to recognize how unlikely it is that a few demonstration projects will adequately address the effects of future development," Montgomery wrote.
You don't indeed. But you also don't need much expertise to wonder how the region can possibly deal with the many square miles already covered by asphalt and concrete, roofs and drainage systems that get rainwater out of sight and out of mind as quickly as possible, and even unpaved areas where sod has been rolled out over impervious hardpan.
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Comments:
Posted Wed, Dec 5, 7:28 a.m. Inappropriate
ABSORBING RUN OFF: THE CITY OF CHICAGO IS REPAVING ITS - I THINK 20 K ALLEYS! - WITH POROUS MATERIAL THAT WILL ALLOW RAINWATER TO GO INTO THE AQUIFER AND NOT INTO THE LAKE. THE SAME I SUSPECT MIGHT BE FEASIBLE FOR MORE HEAVILY TRAVELED SURFACES IF THE RIGHT MATERIAL CAN BE DESIGNED.
Posted Wed, Dec 5, 2:36 p.m. Inappropriate
The EPA has tools too.
Posted Wed, Dec 5, 5:25 p.m. Inappropriate
Permeable Action Now: Daniel Jackson Chasan's article is not only timely but should serve as a call to action. The one initiative that could help Puget Sound within our lifetimes would be a program to (a) motivate builders to construct and buyers to insist upon new construction following LID (low impact development) guidelines, and (b) begin to retrofit existing areas with permeable surfaces and bio-infiltration structures like those in the test blocks in north Seattle. Stewardship Partners is developing standards to certify homes that utilize LID techniques as "Salmon-Safe" as part of our existing third party certification program. The market will reward builders and the voters will reward politicians who move rapidly on this front.
Posted Thu, Dec 6, 9:12 a.m. Inappropriate
The ecological allure of "green roofs" has mystified me for some time. Clean rain water falls on the roof. Part of the water is retained in the roof "soil" and part descends in a pipe.
The retained portion of the water is processed by the plant material and evaporates into the air.
So you, the building, are supporting an ersatz till on your structure, supporting a substantial weight of water, dirt and plant material all for net gain roughly equal to the evaporation
(which could also be accomplish by having pond on your roof).
The other, more obscure, benefits correlate pretty directly to the thickness of the soil. The plant respiration, the filtering, all depend on a rather thick imitation of real till. The thicker and heavier the better.
This all comes at a price, a steep price, and one that becomes truly troublesome when the principal factor, the waterproof membrane fails and all this has to be torn up. You, the building, will find that costly repair is not ecologically sound either.
Just a peeve.
Posted Thu, Dec 6, 1:04 p.m. Inappropriate
They can tell you just exactly how much these regulations add to the cost of a new home. They can also discuss options such as pervious asphalt that help handle rainwater as it hits the surface. Mr. Chasan could have also talked to residents who have installed rainwater handling systems at about $10,000 per housing unit, and then found they had to pay stormwater fees of several hundred dollars per year to their county or municpal government.
Just a thought.
Matt
Posted Fri, Dec 7, 7:57 a.m. Inappropriate
LOTS OF PUMICE AROUND WITH ALL THOSE DEAD VOLCANOES!!!
http://www.thesmartset.com/article/article11300701.aspx
Posted Mon, Dec 10, 8:09 p.m. Inappropriate
The Master Builders are well aware of the cost of the regulations, which is why they hire lawyers (Bob Johns I'm talking to you!) to delay, delay, delay.
I was on Ecology's Stormwater Pollution Advisory Committee from 1998 to 2000, and saw representatives from Seattle, the Port of Seattle, King County, WSDOT, and of course the Master Builders bully, cavil, and delay. Ecology was trying, and to their credit still are, to get a stormwater permit and Pollution Control Manual that might help.
When we let our fellow Americans drown in New Orleans, Chehalis, even the Madison Valley, I don't see how we'll protect water quality and restore the salmon.
Faust traded his soul for ultimate power and knowledge and still regretted his decision. We are giving away our souls.
Urbanus Lux
Posted Tue, Dec 11, 9:30 a.m. Inappropriate
I've actually got a solution...: It's still in the oven - biggest thing missing is the 'position' on my part to see it through over the time it's going to take.
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