Greenwood project finds its footing
Excavators are scooping up mounds of black earth to clear the way for a new shopping complex that could recharge the heart of Greenwood...
Seattle Times staff reporter
How deep do you have to go to hit hard soil?
Seattle Public Utilities commissioned a study in 2003 in response to concerns in Greenwood about sinking soil. The study recommended that withdrawing water from the peat bog should be avoided, and that steps be taken to reintroduce water into the bog to maintain groundwater levels. The city has since prohibited developers from installing underground parking and other below-ground structures in the bog area.
How to read the map: "Cold" areas (shown in blue) have hard soil close to the surface and can support buildings. "Hot" areas (shown in red) do not have hard soil near the surface and may be unstable. The numbers indicate the depth at which geologists detect hard soil deposited some 15,000 years ago; the soil above that depth is not considered suitable for supporting buildings because it is loose to medium in density, consisting of sand, silt, clay and peat.
Excavators are scooping up mounds of black earth to clear the way for a new shopping complex that could recharge the heart of Greenwood — and the fragile peat bog beneath it.
Like much of the neighborhood, the site sits on an old bog that sinks under pressure from above or when the groundwater table is drained.
The tentatively named Town Center, one of the biggest redevelopments ever in Greenwood, is viewed by many residents as a much-needed face-lift for a dated business district but feared by others who say it could do to Greenwood what all the new condos and offices have already done to Fremont and Ballard.
"I think it's going to destroy this neighborhood," said Charlie Leytrowbridge, 24, a regular at Gary's Games & Hobbies. "I definitely feel there's going to be a yuppie invasion."
But Allen Rickert, owner of Top Ten Toys, said he's optimistic the project will complement Greenwood's eclectic mix of small, independent shops that still dominate the business district.
"I'm realistic that change needs to happen," he said, "and I'm hoping it's going to be a good change."
Motorists cruising down North 85th Street might recognize the 5.5-acre Town Center site by the chain stores around it: Fred Meyer to the west, McDonald's to the east and Blockbuster Video to the south.
The city has granted the developer permission to build five buildings, providing about 50 new apartment units and some 80,000 square feet of new and renovated commercial space, with surface parking for more than 300 cars.
Work began last month on the first phase, a three-story building with apartments on top and retail shops on the ground floor. It should open next year.
Town Center is the latest project for an old Seattle family, the Morrows, whose holdings in Greenwood go back more than a century and who now own some 13 acres of prime property in the middle of the retail district.
The development will bring new housing into the heart of Greenwood, create a pedestrian-friendly plaza and increase natural drainage — all improvements the community sought from the developer years ago, said Michael McGinn, former president of the Greenwood Community Council.
But Town Center sits on a part of the bog that geologists say is the least able to support heavy buildings. It will be the first commercial project to be built under new city requirements for such developments in Greenwood, meant to ensure soil stability and protect groundwater levels.
Among other things, builders will pour concrete pilings that penetrate the bog to support the weight of the complex and will create special ditches to allow rainwater to seep back into the earth.
Greenwood's sinking problem is a concern in the neighborhood, where locals still trade stories about homes and condos that sank after the new Safeway was built about five years ago on Greenwood Avenue North.
"They shouldn't be putting big buildings on the bog," said Cindy Benedict, 49. "It's not solid ground. If you stood here and watched a bus go by, you could feel the ground shake."
"Black Dirt Clan"
When Greenwood was platted in 1891, much of it was marshy swamp, unsuitable for building.
Geologists call the area the Greenwood bowl, a legacy of the last glacial push through the central Puget Sound area about 15,000 years ago.
As the glacier retreated, the basin filled slowly with runoff from surrounding ridges and with dead plants and animals, becoming a peat bog — a type of wetland that helped absorb floodwater and fed the headwaters of nearby Piper's Creek.
At the turn of the century, Peter Frank Morrow, a Ballard newspaper publisher, bought 10 acres, and the family developed a farm on one of the basin's knolls, raising chickens, cows and other livestock.
His granddaughter, Patty Ulrichs, recalls catching frogs as a child in the bog during rainy months. "We were called the 'Black Dirt Clan' because we sold black dirt," Ulrichs said. "It was really good, rich soil to grow things in."
By 1910, the Seattle-Everett Interurban Railway's trolleys brought commuters and shoppers along Greenwood Avenue North, and Morrow's land grew in value. But during the Great Depression, the family property was on the verge of foreclosure. Morrow's children collaborated to manage it. They became current on their loan payments, and the land remains in the family to this day. Peter Morrow's great-grandson, Gary Brunt, is property manager for Town Center.
After World War II, the family excavated parts of the bog and built small stores and parking lots.
More development followed, contributing to a hydrologic trend that city planners are only now dealing with: the sinking of the bog and everything built on it.
Peat is soft and must stay bathed in groundwater year-round to prevent it from compressing. As groundwater levels decline and the peat compresses, the settling that occurs cannot be undone.
Over the decades, groundwater levels in Greenwood have been declining — and correspondingly, more areas have been sinking — for two main reasons, geologists say:
With more development, there's less stormwater infiltrating the soil and recharging the peat. And well-intentioned pumps that prevent water intrusion into buildings contribute by extracting precious groundwater from the soil.
No surprise, then, that to the north of the Town Center site, houses have sunk several feet below the sidewalk. Parts of Palatine Avenue North between North 85th and North 87th streets have sunk so dramatically the city has installed barricades to prevent cars from entering that stretch of road.
Protecting the peat
To slow down the sinking, the city required Town Center's developer, Greenwood Shopping Center Inc., to protect groundwater levels.
The peat layer and groundwater start just 5 feet below ground, said Michael Whalen, the project's architect.
Town Center's builders will drill as deep as 33 feet through the silt and peat to reach hard glacial deposits and then fill those bore holes with cement, he said.
In addition, the project will install bioswales to increase the amount of stormwater draining into the soil. The shallow, planted ditches will capture surface runoff that now is diverted to municipal drainage pipes.
To further increase the amount of water getting to the soil, the developer also will use permeable concrete in the sidewalks and permeable asphalt on the parking lot, Whalen said.
On the northwestern corner of the site, the developer is exploring the possibility of an exhibit showcasing the bog and its ecological significance.
To encourage more walking, the developer also will construct a private road connecting Greenwood Avenue North with First Avenue Northwest. It will be called Greenwood Lane and will funnel more pedestrians into the shopping area.
Brunt, the property manager, said he would like small-business tenants to occupy the new retail space, in keeping with Greenwood's unpretentious and casual character.
The Green Bean Coffeehouse seems to exemplify that attitude. Inside the volunteer-run shop, young families cluster around wooden tables, community groups hold meetings and a small blackboard tells visitors to "sit long, talk much."
Nearby, just outside the Greenwood Academy of Hair, a student helps an elderly woman into a waiting car.
Steven Cole, who recently bought the beauty school, said the challenge is holding on to what makes Greenwood special while embracing the economic wave that has transformed Ballard and Fremont.
The neighborhood is watching to see whether chain stores take hold at Town Center. "I hope they give the little guys a chance," Cole said.
Sanjay Bhatt: 206-464-3103 or email@example.com
Copyright © 2008 The Seattle Times Company
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