Low Impact Development
Low impact development, or “LID,” is a strategy to lessen the environmental impact of development by using natural methods of stormwater management. Rather than always using large stormwater ponds that require significant maintenance to catch and treat runoff, LID uses more trees, open space, and plantings to do so.
Sound Transit has incorporated several low-impact development strategies in its projects.
Green construction at Sammamish
The Sammamish Park and Ride lot incorporates environmentally friendly design and construction methods to help water quality protection efforts for nearby Pine Lake.
The unique rain garden incorporated into the site collects water runoff from paved surfaces. A rain garden is a combination of different soil and plant types that absorbs and helps clean runoff water.
After heavy downpours, some rainwater may overflow to grassy ditches, or bioswales, on the site before it flows into a detention pond. The grasses of the bioswale help clean the water before it flows into the detention pond, where remaining silt will settle before cleansed water leaves the park-and-ride lot.
For more information about low impact development, visit the Puget Sound Low Impact Development website.
Rainwater Dispersion System
Sound Transit’s creative application of a relatively new technology used on buildings to deflect rainwater away from buildings is helping to build a more environmentally friendly light rail system. The agency adapted this innovative rainwater dispersion system for use on some aerial portions of its new Link light rail track, currently under construction from Seattle to SeaTac.
Instead of building expensive stormwater detention ponds and vaults, stormwater runoff is being directed to the edge of the aerial guideway. From there, it will fall through the dispersion technology into a soft spray of raindrops to water native plantings under the guideway.
This technology not only saves money, but also results in better habitat conditions under the guideway and in nearby streams.
