The Westwood and Sunrise Heights neighborhoods have been selected to take one for the team: chosen by the King County Wastewater Treatment Division to become home for a series of rain gardens, or bioretention swales, over 40 blocks to help reduce combined sewer overflows dumping into Puget Sound during periods of heavy rainfall.

But many neighbors worry they will see a repeat of a partially botched Seattle Public Utilities rain garden program in Ballard that resulted in several unsightly, stagnant pools that never seemed to drain. Residents reported some were rife with mosquitoes, rats and other critters, and posed what parents felt was a drowning hazard for their children and a significant drop in property value.

The lush rain gardens shown at community meetings leading up to the 2010 project were a far cry from the reality. SPU had to bring in trucks to vacuum the water out of malfunctioning swales on a regular basis.

In the middle of 2011 SPU responded to citizen outcry, including a neighborhood blog detailing the problems (http://ballardraingardengue.wordpress.com/), by removing seven swales completely (out of 59), retrofitting others with “under-drains,” and leaving those already working properly alone, said Susan Stoltzfus with SPU.

King County and SPU have responded with encouragement, stating the two agencies work closely together and learned from the mistakes made in Ballard – mistakes they say won’t be repeated in West Seattle's Barton CSO Project.

The central West Seattle neighborhoods were chosen because studies show 45 percent of stormwater runoff reaching the Barton Pump Station (near Lincoln Park) comes from Westwood and Sunrise Heights. The theory is if the county can capture those heavy rains in bioretention swales, they can guide it below the surface and into the water table, rather than contributing to an average of four yearly overflows at Barton. Those CSO’s dump a combined four million gallons into the Sound yearly, according to the County, and they hope the rain gardens will help reduce CSO occurrences from four to once a year.

King County held a public meeting with the neighborhoods in early February to explain the research done so far (they dug many test pits to understand the geography below the surface), and the plan moving forward. Overall, community response seemed tolerant. There will be the unavoidable changes of less parking as the swales swell into the roads, and for some a loss of landscaping to make room for the rain gardens.

Those things happened in Ballard as well, but the uproar was focused on safety, aesthetics, property value and effectiveness of the swales.

These are the topics that most concern Sabrina Urquhart, a Westwood resident who has researched the Ballard project in-depth, and raised questions to the County.

“The bottom line is I work in communications and I get you have to use certain euphemisms when you are trying to sell things people don’t want to buy … and I would call it a bio-swale or rain garden, you know, but these things turned into ditches in Ballard and they have not convinced me they have resolved all those problems fully,” she said.

Urquhart has been in contact with the community liaison for the project, Kristine Cramer, and shared her concerns with the Herald (she plans to meet face-to-face with the project manager Mary Wohleb sometime in March for first-hand explanations).

With King County and Seattle making a commitment to rain gardens and the likelihood of more neighborhood conversions in the future, we spoke with Wohleb to learn what was learned in Ballard, and how the approach has evolved as a result.

“It is kind of a blessing that we are coming after Ballard because as soon as that situation happened they came to us and said, “Oops, lessons learned and we want to share this information with you” Wohleb said.

Both SPU and Wohleb confirmed the biggest downfall in Ballard was constructing swales without a full understanding of the geography and groundwater.

Wohleb said the West Seattle project has two big advantages over Ballard: time and money. She said King County took the time and spent the money to extensively map the groundwater and geography of Westwood and Sunrise Heights by bringing in the proven consultants, talking with people living in the neighborhoods about areas where drainage is traditionally poor, and testing extensively.

“We have a pretty darn good picture of what is happening underground,” she said. Without that picture, she said they would be installing rain gardens “blindfolded.”

Here are some specific issues Wohleb covered.

24-hour drainage
Wohleb said all of the rain gardens will be designed for 24-hour drainage, “But if you have those odd big storms that happen back to back to back there is a chance you will have a little more standing water in there for a little longer period of time,” especially at the “downgrade” end of a series of swales. She said it will never get the point where King County will have to come out and use trucks to suck water out of the gardens, unless it was plugged up and required maintenance.

Mosquitoes and critters
Concerning rain gardens becoming a gathering spot for raccoons, rats and the like, Wohleb said, “That would be related to a food source. If there is a source of food, you are going to have critters. We are not putting any source of food in there, so it would have to be garbage, it would have to be a source of food.”

She said mosquito infestation should not be a problem because the swales will drain quickly. She said it will be too cold in the winter (when we have our heaviest rainfall) for them to lay eggs, and heavy rainfall in the summer will drain quickly because the soil is dry.

Urquhart still worries periods of sustained rain will attract mosquitoes, mice, rats, possums and raccoons. She was told if nuisance animals became an issue, maintenance staff would remove them, but she wonders if city staff will pull off night time missions when some of those pests are most active.

Parking
“We are very sensitive (to parking issues) and we understand that is a sacrifice,” Wohleb said. The issue is certain rain gardens will have to elbow out into the road, reducing parking on some streets. Wohleb said a parking study was done on evenings and weekends to help inform the ultimate design (these will be built in 2015). She also wanted to assure the neighbors only a handful of swales on a handful of blocks will take away parking, and “Somebody might lose parking in front of their house, but it might be down 10 or 15 feet away.”

Maintenance over time
Urquhart wondered what would happen if funding for the project disappeared a year or two after the rain gardens are installed. According to Wohleb, funding disappearing is “not likely.”

“Not likely,” she said, “because we are treating it like any of our other facilities … it would be like saying we are just going to abandon a pump station or a force main. We are treating it just like any other asset and we are going to fund it and commit to it as an asset in our inventory.”

Property value
For Urquhart, the number one issue is property value. When she expressed her concern over plummeting property value like Ballard residents endured (the Ballard rain garden blog claims real estate agents advised a 15 percent drop in value when the bunk swales were in place), the county sent her a study that found a 2.5 to 5 percent increase in Seattle-area property value in neighborhoods with rain gardens (the study is attached at the top of the story).

“Our results suggest that the low impact development can increase property values,” the study states, continuing“…Our results do not identify precisely what home buyers find attractive about these projects, they merely suggest that (rain gardens) have the potential to produce desirable housing market amenities.”

Wohleb said she could only speak from personal experience, but believes well-maintained swales (“These will be maintained. It’s not like we will be planting them and leaving them; we have a commitment to maintain them long term.”) can be attractive and recommends a walk through West Seattle’s High Point neighborhood for an example.

Speaking of High Point, the gold standard in rain garden implementation for the City, Wohleb said the same consulting firm that designed that project (SvR) is working on this one. The difference between the two: High Point was built from the ground up with rain gardens in mind while this project is a retrofit.

“A lot of the work we are doing now is paying attention to existing conditions (trees, sidewalks, driveways, utilities, width of streets and sidewalks) and then building around that, I call it shoehorning in,” Wohleb said. “That is a challenge.”

Why rain gardens?
Wohleb said the main alternative to rain gardens is building more rainwater storage facilities. She said King County is pushing the rain garden route because it will ultimately reduce costs of dealing with storm water, reduce the carbon footprint at pump stations, and does a better job of filtering out pollutants.

“This is one solution; it is a pretty big scale solution to remove storm water from the combined system in order to have the capacity to reduce overflows into the Sound,” she said, “but there are things people can do that can really impact what goes into the storm water.”

“There are a lot of really cool things people can do on their own,” Wohleb said, recommending a visit to Sustainable West Seattle’s website for ideas on reducing the pollutants we contribute as everyday citizens.

Kristine Cramer is King County’s community contact on the project. She can be reached at (206) 263-3184 or kristine.cramer@kingcounty.gov.

For more information on the Barton CSO Project, visit here.