Several blocks away and seemingly unconnected to the Barton Pump Station located on Puget Sound, the West Seattle neighborhoods of Sunrise Heights and Westwood are in for major changes in the coming years as King County plans to install a series of “bioretention swales,” similar to rain gardens, along many streets.

The need, according to county officials, comes from Washington State’s Department of Ecology mandate that King County reduce the number of combined-sewer overflows into Puget Sound from four (the current average) to one event a year. The neighborhoods were chosen because they contribute 45 percent of the water and sewage processed by the Barton station.

A series of biorention swales will be installed between sidewalks and roads, which are basically troughs meant to capture capture rain water from the roads and divert them through deep infiltration wells into the water table below West Seattle. By keeping that water out of the combined sewer system, King County intends to reduce overflows into the Sound.

On June 23, a small number of neighbors living on the 7300 block of 30th Ave S.W. met with King County and SVR (the firm designing the project) representatives for an eyes-on look at how their street will change. King County held similar meetings along all the effected blocks over that weekend.

Since the project was announced certain residents have been vocal in their opposition, citing loss of parking where curbs bulb out to make room for the swales, concern over drops in property value, safety issues when the troughs are full of water during (and up to 24 hours after) major rain, the inconvenience of walking around troughs to get to and from their vehicles and homes, worries the swales may look good initially, but will become weed-infested eyesores over time, and disappointment with the inevitable removal of some trees.

Those concerns were reiterated during the meeting with 30th Ave S.W. residents, but others took the information in and said they were at peace with having a swale installed in front of their home, meaning less yard work and taking comfort in the greater good for Puget Sound water and aquatic life.

“This all sounds good to me,” one neighbor said. “One less thing to cut.”

The face-to-face meetings allowed residents to understand specifically how their block will change, although Kristine Cramer with the county made it clear the plan is only one-third complete, so there is still time to make changes and work with neighbors.

While the High Point neighborhood to the north of Sunrise and Westwood has been haled by Seattle and King County as a positive example of how rain garden projects can work well and look nice, it was noted at the meeting that upkeep has fallen behind recently as the troughs fill with weeds.

Cramer said the biggest difference between High Point and this project is while High Point is maintained by a private company, this one will be maintained by King County.

A maintenance plan hasn’t been drawn up yet, but Kramer said the county will commit to keeping up on watering, weeding and regular upkeep to keep water flowing quickly through the swales and into the pipes while maintaining the aesthetics.

Steve Burke with SVR was asked why the county doesn’t just change West Seattle’s waterworks from a combined sewer/rainwater system to separate systems. He said the cost of tearing up streets across the peninsula to make that change is prohibitive.

Construction is expected to start in one year, and Kramer said each block will take about three months to complete. The entire process will take around two years.

A recently published King County press release addresses several concerns with the project, and can be read here.