Leschi South Marina Wave Attenuator and Facility Improvements

Location

Leschi South Moorage; 100 Lakeside Ave S. 

Map

Budget

$13.2 Million 

Schedule

Upland utility work September 14, 2026 and continues for 3-4 months.

• The upland utility installation is necessary to support the new vessel sewage pump station which will be constructed in the marine stage of this project, as described in the next subsection below. The purpose of the pump station is to enhance Lake Washington's water quality.
• Harkness Construction, the contractor selected through a competitive bidding process for this stage of the project, will mobilize to site on September 14, 2026. Work is expected to take 3-4 months, depending on the weather.  Some work on Lakeside Ave will occur at night.
  • Night work dates and times will be communicated once determined, depending on weather and the pace of the work. Night work is currently not expected to occur until the end of October at the earliest.  Work will start in the evening, and the noisiest work activities, such as saw cutting and jackhammering will be performed before 10 PM.  This work is being performed at night to allow for parking and deliveries to occur at the Leschi Market during business hours, and will mostly impact the southbound traffic lane at Lakeside Ave.  Work, as feasible, on the northbound traffic lane will occur during the day.
  • Required curb ramp construction will occur during the day.
  • Stakeholders will be updated periodically.

Parking and Traffic

Baseline Parking - Prior to Sept. 14, 2026; and restored after completion of project

Parking in the Leschi neighborhood prior to construction will be restored after completion of the project.  The baseline parking arrangements include:

Leschi South Marina:

• Park Parking Lot on the pier (in green, 39 spaces)
• Marina Tenant Parking along the lakeside strip of an onland parking lot (in red)
• Public Off-Street Parking on the inland strip of the onland parking lot (in orange, 21 spaces)
• Public parallel parking along both sides of Lakeside Ave S

Between the Marinas

• Bus stop on Lakeside Ave S northbound, with parallel street parking for the remainder of the block north of it
• Parallel street parking across from the northbound bus stop
• Bus stop southbound on Lakeside Ave S, with parallel parking on the block south of it.

Leschi North Marina:

• Marina Tenant Parking (in red), along the lakeside strip of an onland parking lot
• Park Parking Lot stalls (in purple), along the inland strip of the onland parking lot
• No street parking and no parking pier

Adjusted Parking During Construction (Sept. - Nov. 2026)

Using the same visual, the graphic below shows parking impacts from September 14, 2026 to early November, weather permitting. Approximately 200 parking spots for public use, marina tenants and park users remain on parkland and right-of-way.

Larger graphic available upon request.  Image described as follows:

Leschi South Marina:

• Park Parking Lot on the pier (in green) -- CLOSED FOR CONSTRUCTION.
• Marina Tenant Parking along the lakeside strip of an onland parking lot (in red) -- APPROXIMATELY 3 STALLS CLOSED FOR CONSTRUCTION, the stalls located nearest the parking pier.  The majority of this zone remains open.
• Public Off-Street Parking on the inland strip of the onland parking lot (in orange) -- Remains open during construction
• Public parallel parking along the northbound lane of Lakeside Ave S, adjacent to the onland parking lot (in yellow) -- APPROXIMATELY 3 SPACES CLOSED FOR CONSTRUCTION, nearest to the parking pier. Intermittent, limited-duration closures for material and equipment deliveries will affect the full length of the parallel parking zone.
• On the southbound (western) side of Lakeside Ave S, the bus stop will be temporarily relocated to mid-block.

Between the Marinas:

• Bus stop on northbound (eastern) side of Lakeside Ave S will relocate to the northern end of the block.
• The space normally used by the bus stop will be converted to street parking and/or Load/Unload Zone, with one temporary accessible parking space.
• No changes on the southbound (western) side of Lakeside Ave S.

Leschi North Marina:

• No changes to Leschi North Marina parking.
• Marina Tenant Parking (in red), along the lakeside strip of an onland parking lot
• Park Parking Lot stalls (in purple), along the inland strip of the onland parking lot
• No street parking and no parking pier

Detail map showing only Leschi South Marina:

Marine Construction September 2026 through Spring 2027

• Manson Construction, the contractor selected for this stage of the project through a competitive bidding process, will mobilize to site in late September/Early October to remove large debris, that were too large for the dive team contracted for earlier cleanup work, from under Leschi South Marina. No community impacts anticipated.
• Off-Site Fabrication of floats, piles and gangways will start in September 2026.
• Manson Construction, the contractor selected for this stage of the project through a competitive bidding process, will mobilize to site in late September/Early October to remove large debris, that were too large for the dive team contracted for earlier cleanup work, from under Leschi South Marina. No community impacts anticipated.

Project Need

The existing timber dock, supported by creosote treated piles, is nearing the end of its useful life. Creosote is bad for the environment and should be removed whenever possible. In addition, the pipe pile breakwater does not protect the marina from wave action. There is also no public transient moorage or boat sewage pump out in this part of Lake Washington. The existing dock is not accessible to all ages and abilities.

Project Benefit

This project provides a brand-new public dock, breakwater, and associated utilities – including a sewage pump out facility for boats and the removal of the outdated and environmentally harmful creosote dock to enhance water quality in Lake Washington. Removing creosote from the water will benefit the aquatic ecosystem.  Providing a sewage pump out facility will help keep Lake Washington clean.  The new breakwater will protect the marina from damage due to wind and wave action.  The moorage facility will allow the boating community to dock at this location.  Public access, including some seating, will also be provided.

Community Participation

Community input is ongoing. Please contact Stephen.Levengood@Seattle.Gov with any questions or concerns regarding this project.