During the past 12 months, the Park Lane project team has been working with residents and business owners to redesign Park Lane into a greener, more walkable and vibrant corridor. Park Lane’s new plaza-style street will feature a one-level surface of brick pavers and a new stormwater system that will better protect Lake Washington from the pollutants that drain to it every time it rains.

Starting Jan. 5, Kirkland’s contractor, Marshbank Construction, will begin working on that new vision. This will involve some dramatic changes, such as closing the street to automobile traffic and progressively removing all of the existing sidewalk and pavement.

One of the most visible changes will be to Park Lane’s treescape. The contractor will be removing all but nine of Park Lane’s existing trees.

“Some of them are diseased,” said Project Engineer Frank Reinart. “Most of them are old and some of them are in the way of new utilities. But the underlying reason we are replacing the trees is to make Park Lane more walkable and accessible for pedestrians of all abilities. The current conditions of the trees make it hard for people, in groups or with assistance, to walk the length of Park Lane.”

Reinart points to the maple in front of Cactus Restaurant. That tree’s base and root mass protrude above the sidewalk’s surface, reducing to a couple feet the walkable space between the base of the tree and the street on one side, and Cactus’ fenced dining area on the other side.

“A wheelchair can’t fit through that space,” he said. “A person walking with a child might be forced to step into the street. And this is only one such example on Park Lane.”

Pedestrian access is the primary reason for removing many of the trees. But other reasons exist. The maples in front of Zeek’s Pizza and Cactus, for example, are aging. The maple on the northwest corner of Main Street and Park Lane conflicts directly with the project’s replacement water main. Ten more trees—most of them maples—would not survive the root damage they would sustain while crews build the street’s new underground utilities and its walking surface.

Altogether, the project will remove 27 trees, including an ailing oak removed earlier this year. It will plant 35 new trees with five different species be planted. Those species include the more familiar Red Maples and Red Oaks, as well as the tall and slender Musashinos and the broader Redspire Pears and Pink Flair Cherries.

All of these trees share a common characteristic:

“They’re all appropriate for the street,” said project team member Eric Schmidt, a principal at the Cascade Design Collaborative. “Unlike the trees that are out there now, they won’t grow too tall—maybe 40 to 45 feet. Together, they’ll provide an attractive canopy. They’ll also have a smaller tree base with a root mass that will remain underground.”

This underground root mass, says Schmidt, will help protect Park Lane’s new street from surface-busting root-intrusion.

Unlike the existing trees, the new trees will also benefit from more sensitive planting techniques and contemporary construction practices. Marshbank will plant all of the trees in reinforced structural soil—a combination of gravel, topsoil and structural devices that strengthens the road’s integrity and, at the same time, ensures tree roots have plenty of deep, loose soil through which they can chase nutrients, air and water. This will help protect the trees from a common cause of poor health: the tightly-compacted soil beneath streets and sidewalks.

The existing trees were not planted using these more sensitive techniques. The consequences to Park Lane are visible today.

Back in the late 1970s, when the trees along Park Lane were planted, arborists nursed street trees in buckets, which caused their roots to coil. A backhoe or drill then dug the holes in which they were planted, unintentionally creating a seal of compacted soil around the inside of the root well. That, said Schmidt, exacerbated the trees’ root-coiling tendencies. Once the roots did manage to grow, they grew shallow in search of water, buckling sidewalks and struggling in an environment of excessively compacted soil, building walls, maintenance root-trimming, new utility cuts, and the occasional impact of automobiles.

“Replacing the trees gives us the chance to use the best methods possible,” Reinart said. “For the trees and for the people who want to travel Park Lane.”

For project information, visit www.kirklandwa.gov and search “Park Lane,” or contact Christian Knight, Capital Improvement Program, at 425-587-3831 or cknight@kirklandwa.gov.