Sub Basin 22 & Sub Basin 25 b Watercourse Stabilization

Project ID: 
SW0132, SW0133
Project Type:
Storm
Project Status: 
Planning/Design

project location​​Project Status

To help keep area residents informed of our construction progress, we will post project updates to this site on a regular basis. Click here to see status updates.

Project Details/Neighborhood 

  • Sub Basin 22- Watercourse lying west of West Mercer Way, near 4251 West Mercer Way

  • Sub Basin 25b - Watercourse extends westerly from 84th Ave SE downstream to Forest Ave

​Background

Stream banks have eroded over time, causing significant sedimentation downstream.

Description

Sub Basin 22- 140 linear feet of channel restoration will include regrading of the eroded channel, installation of streambed gravels, and placement of woody debris to stabilize the watercourse. Project will also include riparian planting along the banks.

Sub Basin 25b- 220 linear feet of channel restoration will include regrading of the eroded channel, installation of streambed gravels, and placement of woody debris to stabilize the watercourse. Project will also include riparian planting along the banks.

Project Timeline

Planning/Design 2024
Construction Summer 2025

Estimated Budget

Sub Basin 22
Engineering $50,000
Construction: $130,000

Sub Basin 25b
Engineering $50,000
Construction: $100,000

Contact

Elayne Grueber, P.E., Capital Project Manager, elayne.grueber@mercerisland.gov  

www.mercerisland.gov/SW0132  www.mercerisland.gov/SW0133

 

 
Status Updates

June 2024

Work on the design continues with the next submittal from the consultant expected in July.  The US Army Corps of Engineers (USACE) is in the final phase of their agency review. 

May 2024

The consultant is currently working on the 90% design and is incorporating comments from the City.  City continues to work with regulatory agencies for permitting. 

April 2024
60% design comments were sent to consultant to incorporate.  City continues to work with regulatory agencies for permitting.

November 2023

City receives comments from WDFW.

June 2023

Sub Basin 22- City receives SEPA approval for project. Project design on hold waiting for regulatory comments.

January 2023

City applies for SEPA and USACE permitting for the project.

November 2022

60% design submitted by consultant Gray and Osborne for City review.

October 2022

Subconsultant to Gray and Osborne complete the wetlands assessment report for the site.

August 2022

Subconsultant to Gray and Osborne completes geo-technical assessment report for the site.

March 2022

Gray and Osborne hired to perform environmental studies and design.