In November 2006, a major flood event caused catastrophic damage to Index-Galena Road. High flows from the North Fork Skykomish River washed out multiple sections of roadway between MP 6.4 and MP 6.9 that eliminated vehicular through-access. A side channel of the river now occupies extensive sections of this portion of the Index-Galena Road roadway alignment. The 2006 flood damage event resulted in Index-Galena Road being closed at MP 6.4, just east and upstream of the Snohomish Co. Trout Creek Bridge #494 at MP 6.05.
The principal deficiency of Index-Galena Road is its location. The current alignment is in both the 100 year flood plain and the channel migration zone as identified in a hydrologic study completed as part of the alternatives analysis. The road has been washed out at its current location three times since 1980; this event is the fourth.
The proposed project moves the alignment upslope, beyond the 100 year flood plain and substantially out of the channel migration zone. The road has been lengthened to 0.95 miles and now runs from MP 6.08 to 7.03. Structural solutions have been developed for habitat preservation in consultation with the U.S. Fish and Wildlife Service, National Marine Fisheries Service, and USFS. A plan for naturally occurring debris movement that will avoid endangering the road is in the evaluation phase. An environmental assessment (EA) is nearing completion.
The Purpose and Need for the project was reaffirmed by FHWA, WSDOT, USFS, and Snohomish County Public Works in February 2015.
The purpose of the proposed Index-Galena Milepost (MP) 6.4 to MP 6.9 project is to restore essential travel and prevent future damage to the roadway. Essential travel includes re-establishing access for property owners with land holdings in the North Fork Skykomish River valley upstream from the town of Index, re-establishing multi-purpose public recreational access to the North Fork Skykomish River valley, re-establishing vehicular access for emergency service providers to these properties and users and re-establishing administrative access for the U.S. Forest Service to manage their lands located in the Mt. Baker Snoqualmie National Forest.