In 1999, Seattle Public Utilities went on the offensive with its natural drainage systems program, launching innovative streetscape designs that boosted the beauty of the neighborhoods while reducing the negative impact of stormwater runoff on creeks, lakes, and bays.
Since then, five projects—including complete redevelopment of a 129-acre residential area—have been put into action. Here, Seattle's low-impact development (LID) program manager Tracy Tackett lays out the path to the city's success.
Why is LID important?
Traditional stormwater management practices aren't protecting our water resources to the extent we need. Traditional methods are space-intensive; as we get more developed, space is at an increasing premium. LID also is much more cost-effective. Taking a LID approach allows you to take advantage of multiple environmental benefits. You end up with additional green space to create habitats, green roofs to provide insulation, cisterns to provide another water source, and anything that involves infiltration to help recharge groundwater. In time, all of this will become more important as drinking water resources become more scarce.
What actions did the city take at the onset?
We have a lot of unimproved areas in Seattle. These areas don't have curbs, gutters, or sidewalks; we wanted to improve these areas, but in a creek-friendly manner. The merging of those two goals is what led to our first big project, “SEA Streets,” or Street Edge Alternatives. We conducted a stormwater retrofit of a residential block, a site we picked because of flooding problems and to protect a salmon habitat in the watershed. We reduced impervious surfaces to 11% less than a traditional street, provided surface detention in swales, and added more than 100 evergreen trees and 1100 shrubs. Runoff from this block has been reduced by 98%. People really took well to it, and our LID program has been growing ever since then.
Do you find it hard to get the LID message across to the public and developers?
Here in the Northwest, the word about LID has spread rapidly, and people are really interested in it. Our efforts are more about making it clear that the facilities being placed aren't just aesthetic features, but that they do important work. A lot of people get it and they know it's the right thing to do but need the nitty gritty—what exactly needs to be done from a regulatory standpoint—to make the permitting process easier. Leaders can help by simply providing clear guidance and direction to folks.
What advice would you give to PW leaders looking to implement and strengthen LID practices?
Make your stormwater guidelines clear: These are the practices, this is how we want them to be implemented, here are the variations. Be very clear with permitting agencies. This all needs to originate internally from the city, especially when it comes to rights of way—there are so many details to work out with all the players. It's hard for developers to come up with all of that on their own. You need a champion within the city government to get that going.
Read other articles in our "Green Matters" special report:
- Team Green: introduces you to a water district that decided to build green, and offers tips on how you can do it, too. It also provides a snapshot of how the solid waste department serving Florida's capital implemented a green demolition of its administration building.
- Auditors Welcome: shows how auditing a department's facilities can provide a step-by-step plan for using less electricity and water.
- Trickle-Down Effect: A story from Chicago shows how one of the nation's largest cities reduced storm-water runoff in its alleys by using specially designed pervious pavement.
- Resource List: A list of useful links for organizations and associations that can help you make you're department more sustainable, and planet-friendly.