Gallagher Hill Erosion Control Project Underway

Ed. Note: This post is a city of Mercer Island press release.

A new stormwater project within the Gallagher Hill open space will protect Lake Washington from siltation and water quality problems due to erosion associated with high flow events and down-cutting of the stream channel.

The two-phase project includes stormwater piping on the hillside (currently underway), and then in-channel work (starting mid-September), for a total cost of $327,000 which includes design, construction, and management.

Construction will restore a 600-foot reach of stream and 200-foot reach of tributary.  The stabilization work will utilize bio-engineering and sustainable practices as much as possible, including installation of natural controls such as large woody debris, stream rocks and boulders; invasive plants will be removed, and disturbed areas will be replanted with native vegetation.    

For more information, contact project manager Fred Gu; for a map of the project (#ST-1) click here.