Sub Basin 22 & Sub Basin 25 b Watercourse Stabilization
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
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Sub Basin 22- Watercourse lying west of West Mercer Way, near 4251 West Mercer Way
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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.
SW0132 PROJECT LOCATION (351 KB) SW0133 PROJECT LOCATION (336 KB)