US 101 Elwha Bridge Replacement Downstream Mitigation
The Washington State Department of Transportation (WSDOT) will be replacing the US 101 Elwha River Bridge. Construction is anticipated to start in 2023. An Environmental Assessment (EA) was prepared for the US 101 Elwha River bridge replacement (US 101 Elwha Bridge EA ("2021 EA")), and a Finding of No Significant Impact (FONSI) was published by the Federal Highway Administration (FHWA), WSDOT, and the National Park Service (NPS) in 2021. Construction of engineered logjams (ELJs) is required as compensatory mitigation, per consultation with the Lower Elwha Klallam Tribe (LEKT) under asserted treaty rights and with the U.S. Army Corps of Engineers (USACE) pursuant to Clean Water Act (CWA) Section 404 Permit requirements. Mitigation is for the riverine impacts from the bridge replacement project and for riverine impacts that occurred due to emergency scour countermeasures constructed in 2016 and 2017 and is the subject of this EA.
The project need is to improve river channel dynamics and provide salmonid habitat as compensatory mitigation for riverine impacts downstream from the US 101 Elwha River Bridge demolition and reconstruction project.
The use of ELJs was identified in the 2021 EA as compensatory mitigation per the USACE CWA 404 Permit consultation, as well as per consultation with the LEKT under asserted treaty rights. The lands where the ELJs are proposed for installation under the 2021 EA are "Elwha Project Lands." These lands were legislated to Olympic National Park (ONP) under the Elwha River Ecosystem and Fisheries Restoration Act of 1992 ("the Elwha Act") for purposes related to dam removal and restoration efforts. While these lands are not within the park's established boundary, they are temporarily managed by the NPS and are subject to the Department of the Interior (DOI) and NPS National Environmental Policy Act (NEPA) compliance and other legal requirements until subsequent legislation is passed turning these lands over to a permanent management entity. Due to the land designation, WSDOT and FHWA need to acquire a Highway Easement Deed (HED) from the NPS for bridge and ELJ construction. For DOI and NPS NEPA compliance, the impacts of this compensatory mitigation measure must be considered and the analysis provided for public review. While due to the project need, this is considered a connected action, though addressing river channel dynamics could be an action independent of bridge demolition and construction. This EA is therefore tiered to the bridge reconstruction EA (2021 EA) and analyzes only the installation of the proposed ELJs.
The purpose of the project is to: (1) maximize channel length to the greatest extent possible, (2) create and sustain as many pools as possible, and (3) create stable alluvial islands for forests to mature to improve shading of the river and provide a long-term source of large wood, all to improve river channel dynamics and provide salmonid habitat as mitigation for riverine impacts from bridge demolition and construction.
ONP Planning and Compliance Program Manager
For Media Inquiries:
Molly Pittman, Public Affairs Office, Olympic_PAO@nps.gov, 360-565-3005