Waterfront Trail Restoration Project Gets the Green Light

Arboretum Waterfront Trail, with a view of Union Bay. (Photo courtesy Seattle Parks and Recreation)

At the Arboretum Foundation’s Annual Meeting on June 18, Seattle Parks and Recreation (SPR) superintendent AP Diaz delighted attendees with news that the project to restore the Arboretum’s Waterfront Trail has finally gotten the go-ahead.

The trail along the shoreline of Foster Island connecting to Marsh Island and the Montlake Lid is one of the Arboretum’s most spectacular and popular features. It offers scenic views of Union Bay and amazing opportunities to encounter wetland plant and wildlife biodiversity in the heart of the city. However, the trail is well overdue for a makeover. Portions of it are often submerged or difficult to navigate, especially in the spring and summer months, when the Army Corps of Engineers raises the water level in Lake Washington.

Designs for rebuilding portions of the floating boardwalk and on-grade paths have been in the works since 2018. However, a permitting backlog and delay at the state and federal level—caused by the Covid pandemic and changes in the federal review process—put the project on hold.

Design plan for phase 1 reconstruction of the trail on Foster Island. PLEASE NOTE: this image is not entirely up to date on project scope/construction methods.

Now, SPR has the permits in hand to move forward with the bidding and construction of phase 1 of the project, which encompasses the trail and floating boardwalk restoration on Foster Island. The design supports and expands ADA access to the trail. It also enhances wetland habitat by replacing in-fill trails (which require regular mulching with wood chips) with HDPE-pipe-foundation elevated boardwalks.

To reduce the impacts of construction on fish in the lake during their most sensitive life stages, work can only take place during an authorized time window, in this case, later summer and fall.

“We’re excited that phase 1 is moving ahead,” says SPR project manager Jonathan Pagan. “We expect construction to begin in the next water works window, which starts July 2026. However, we won’t have a final schedule until a contractor is selected. The bidding process for hiring the contractor should take about three months or so.”

In other good project news, SPR has received $1.1 million from the Seattle Parks District Fund to complete the design of phase 2, which encompasses the trail restoration on Marsh Island. The total budget for the project is now at $2.45 million and includes mitigation funds from the 520 Bridge reconstruction project.