One of the biggest problems for protecting Puget Sound as well as other water sources is the contaminants found in runoff water.  As rainwater flows over polluted streets and buildings, it picks up a load of pollutants, such as oil and pesticides as it flows into drainage systems and then into a stream or lake or the Sound.

The city of Seattle, partnering with Vulcan Inc., is experimenting with what they are calling the "Swale on Yale", a 10-ft. wide stretch of natural plants and grasses that is designed to clean up about 188 gallons of water each year, according to an article in today's PI by Robert McClure.

Tracy Tackett, low-impact development program manager for Seattle Public Utilities, says that this is the first large-scale, urban stormwater project.  Portland has tried a few smaller projects, apparently quite successfully.  According to the PI article:

"The cost is estimated at $8 million. Vulcan is paying what it would normally pay to build the sidewalk and other traditional streetside features, about $1 million. The city will pay the rest, and it hopes to join with other private developers in the future where such a project would work.

"Vulcan will be getting a nice streetside amenity, but it also will be giving up several things: about 4,500 square feet of potential development and all the parking along its side of the streets -- about 50 spots."

A recent state administrative court ruled that Seattle and other large cities in the Puget Sound region will have to start requiring developers to use "low-impact development" techniques, such as the swale, to control stormwater runoff.  This is one of the first instances where the requirements of the new program is being tried.