City celebrates completion of South Detention Vault in Overlake Village

Published 10:14 am Wednesday, September 30, 2015

It’s been a long time coming, but after about eight years since its inception, the South Detention Vault in Overlake Village is now complete.

And to mark the occasion, the City of Redmond held a small event Tuesday afternoon to celebrate and recognize those involved in the project.

Plans for the vault first began in 2007 as the city began looking at developing the Overlake neighborhood into an urban center. It was completed in July.

Redmond Mayor John Marchione said in looking at development, the city worked from the ground up, putting in place the infrastructure needed to prepare for growth. That growth, he said, will manifest in the form of about 5,000 new residents and about 25,000 jobs for the area by 2030.

As previously reported, the vault is a regional facility, meaning large developments, such as the planned 28-acre urban center at the old Group Health Cooperative site, can just connect a pipe to the South Detention Vault. They won’t need to build a separate vault on their site and consequently, will save money. These savings will attract developers and as a result, trigger redevelopment to the area.

“It was a job creator. That’s what I saw the project as,” said Joe O’Leary, a city senior engineer and project manager for the vault.

At 533 feet long, 123 feet wide and 17 feet tall, the vault is the largest of three stormwater vaults that will be built in the area. It can hold up to 6.5 million gallons of water — about 10 Olympic-sized swimming pools. The water will be draining from about 322 acres of the surrounding neighborhood, including Microsoft and the future Overlake Light Rail station.

The South Detention Vault — along with the remaining two planned vaults — will help with managing stormwater runoff, improving water quality of nearby creeks by reducing erosion in downstream creeks where salmon spawn. The salmon species in the area streams are Coho, Chinook and Sockeye.

“These are Bellevue salmon, so they’re not as good as Redmond salmon,” Marchione joked with Tuesday’s crowd. “But they’re still quality fish.”

With this predicted impact on the environment, the city was able to apply for a grant with the state’s Department of Ecology. O’Leary said they received $1 million.

The total cost of the Overlake detention vault is estimated at $21.5 million. Roughly $3.9 million was for the preliminary work and final design and about $17.6 million is for the final construction costs.

While the site of the South Detention Vault has been paved over and currently serves as a parking lot on the east side of Sears, Marchione said there are future plans for the space to be turned into the park. Though, he said, that is probably still a decade or two in the future.

In thanking all of the agencies, organizations and companies involved in the project, O’Leary gave a special thanks to the staff at Sears. He said the city saved about $100,000 thanks to the store’s cooperation when it came to dealing with truck deliveries to the construction site. O’Leary said the city had set aside that money for mitigation expenses, but the Sears staff was very easy to work with and they were able to handle the deliveries without much disruption or need for mitigation. These savings, he said, had a lot to do with the project coming in under budget.

In addition to Sears, O’Leary also thanked other groups the city worked with on this project, including the Department of Ecology, Redmond design firm Otak, Inc., earth science and technology advisers GeoEngineers, HDR Engineering, contractors Goodfellow Brothers and Seattle construction company Franklin Pacific.