Seattle Sun Newspaper - Vol. 8, Issue 3, March 2004

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Thornton Creek plan unveiled at meeting

By JAMES BUSH

It looks like a creek, has year-round flow like a creek, and allows for fish passage, should any salmon be ambitious enough to swim all the way from Lake Washington to Northgate.

But the proposed stream channel across half of Northgate Mall's former south parking lot, unveiled by two citizens groups, Thornton Creek Legal Defense Fund and Citizens for a Livable Northgate, at a Feb. 19 public meeting, would also function as a detention system. During normal storm events, it would hold storm water at the site and lessen the threat of downstream flooding.

Conceived by landscape architect Peggy Gaynor and Pace Engineers after just two meetings late last year, the plan certainly looked like a winner to more than 50 people who crowded a banquet room at the Northgate Ramada Inn.

Developer Bruce Lorig, who is considering building a mixed-use development which would share the eastern half of the south lot with the 2.7-acre landscaped stream corridor, sounded the night's only note of caution. "We actually have a long way to go before we have a building on this site," he said.

His company, Lorig Associates, has yet to sign a purchase-and-sale agreement with Simon Property Group, the Indianapolis-based owners of Northgate Mall. Plus, Lorig is counting on the City Council not only to approve a new tax abatement program for multi-family development, but to also add Northgate to the list of eligible neighborhoods.

It's hardly a long shot. Council member Nick Licata, who served as the master of ceremonies for the event, and Council member Richard Conlin, who was the final speaker, both say they think the legislation can get majority support.

Gaynor gave the major part of the briefing on the creek proposal. She proposes tapping into the underground drainage pipe which now transmits the creek under the ocean of pavement. Due to springs and other groundwater activity, the creek will maintain a small, but constant, flow of about 1 cubic foot per second (roughly half of Ravenna Park's spring-fed Ravenna Creek). The existing pipe wouldn't be removed, but maintained as an underground storage facility to handle excess flow caused by severe storms. But most storms would simply spread water along a flood plain ranging from 16 feet to 40 feet in width, held in place by pedestrian bridges that double as weirs (flow-restricting structures).

There are tricky engineering aspects to the Gaynor/Pace proposal. As moving water through vegetation helps to cleanse it, Gaynor proposes sealing off all but the top portion of the huge drainage pipe (in excess of five feet in diameter) to increase the slope and aid gravity flow across the site. This technique, known as backwatering, would mean that, instead of holding just the usual trickle of constant flow, the pipe would be almost completely filled with water at all times. It would also raise the water level in surge ponds alongside Interstate 5 and across the highway at North Seattle Community College. "We're going to make this pipe work harder than it does now," says Gaynor.

This proposal will undergo formal review by Seattle Public Utilities, alongside an SPU proposal which would create a similar channel, but use it to treat storm water conveyed from nearby neighborhoods (the pipe below the south lot would remain in place). Also studied will be a full creek daylighting alternative drafted by Gaynor in 2001. In an Feb. 19 letter to Lorig, SPU Director Chuck Clarke said his engineers have some concerns about that the proposed backwatering could increase flooding risks upstream.

But it's hard to deny the aesthetic benefit of constant stream flow and the ease (and low cost) of obtaining water from a pipe already on the site. Which was just one more reason the briefing took on the air of a celebration, especially given the number of proposals the community has seen to simply cram buildings on the site and leave the stream buried.

John Lombard, president of Thornton Creek Alliance, said that creek backers have always supported sharing the site with new buildings. "We're just for good development, not stupid development," he added.

Lorig's general outline of his thoughts for the site included two major retail buildings with five floors of housing atop each, plus a few smaller buildings and more housing units strung along the edge of the creek corridor. All of these structures would be built north of the creek corridor; nothing has yet been proposed for a small site on the corner of NE 100th Street and 5th Avenue NE.

The developer, best known for adaptive reuse of historic buildings in projects such as the Queen Anne High School residences and the mixed-use Wallingford Center (the former Interlake Elementary School), says he envisions creating 300 to 350 apartments in buildings of five to seven stories. The lower floors of these structures would include retail slots for a grocery store and several other major retailers.

While the December agreement between Mayor Greg Nickels and the council majority set up a formal Northgate area stakeholders group, many in attendance insisted that public meetings also be held before any final decision is made.

Conlin agreed, saying that the stakeholders group "is not intended to be a substitute for community process."