May 21, 2014

Kirkland's plan for a ‘festival street' includes stress test for street trees

Photo courtesy of the city of Kirkland [enlarge]

City arborist Mark McDonough checks the roots of a tree during a stress test as consulting arborist Scott Baker directs a crew to pull the tree’s bough.

The city of Kirkland is working on a $3 million plan to improve Park Lane, a popular pedestrian corridor between downtown and the Lake Washington waterfront.

The narrow, two-block Park Lane runs between Lake and Third streets, and is lined with trees, shops and restaurants.

The city wants to turn Park Lane into a plaza-style “festival street” that can be closed to traffic for events. Bollards, street furniture and landscaping will be used to help separate pedestrians from vehicles.

Perteet is doing the design, which is around 30 percent complete. The project will also include replacing the water main.

The city has done some informal polling about the design with residents, who said they favored classic streetscapes with lots of brick, planters and space for outdoor dining. East Fourth Street in Cleveland and the downtown mall in Charlottesville, Virginia, are examples of this kind of street.

The Park Lane advisory group will hold a public meeting at 10 a.m. today in the Kirkland Library at 308 Kirkland Ave. to discuss the project. The meeting is the second of a half-dozen such meetings the city will hold throughout the design process.

Construction is scheduled to begin in January 2015 and finish four months later.

Part of the project will involve replacing trees that are damaging sidewalks and are in poor health.

Christian Knight, a city outreach coordinator, said tree roots have lifted sidewalk panels and that creates tripping hazards. Panels have been repaired and replaced over the years but he said the street has lost its cohesive look and some of its charm.

Eric Schmidt is a landscape architect from Cascade Design Collaborative and is working on the Perteet team.

He said some of the trees on Park Lane would live for only another five or 10 years. “To save this green canopy and parklike atmosphere for now and the next generation, we need to improve the conditions of the healthy trees and replace the ailing ones.”

Roots of the new trees will be protected by an underground soil cell system that prevents the soil from compacting under pavement and heavy traffic loads, allowing roots to grow deeper into the ground.

The soil cell systems, which look like giant milk crates, also serve as rain gardens, absorbing stormwater runoff into the loose soil.

The city hasn't determined how many trees will be replaced. Healthy trees will be kept and pruned.

King County recently completed a $20 million pump station at Park Lane and Third Street that included street improvements. The county restored around 100 feet of Park Lane to fit in the festival street design the city is planning, with a curbless surface, pervious pavement, rain gardens and benches.

Knight from the city said some of the county's street work is likely to be redone or augmented to fit the rest of the project.

Half the funding — $1.6 million — comes from a pair of government grants: one for stormwater improvements and the other to make the area more walkable. The city is providing the remaining $1.4 million, some of which is for first-phase work that was completed in 2010.