Other Agencies with Actions or Authorizations:

Department of the Army, US Army Corps of Engineers - Regulatory

Washington

Department of Homeland Security, US Coast Guard

Department of Commerce, National Oceanic and Atmospheric Administration

Department of the Interior, Fish and Wildlife Service

Description:

This project proposes to improve the I-5 corridor from Marvin Road to Mounts Road (Exit 111 to Exit 116) to:
• Enhance mobility and connectivity on I-5 for passenger vehicles, freight, transit, and active modes and provide support for increased person and freight throughput.
• Improve local and mainline I-5 system resiliency.
• Enable environmental restoration and ecosystem resiliency at the I-5 crossing of the Nisqually River Delta area.
• Support economic vitality through reliable and efficient freight movement and access to major employers.

The Planning and Environmental Linkages (PEL) study completed in July 2023 recommended alternatives (Build/No Build) to be analyzed in the NEPA process. Within the range of recommended transportation alternatives there are two design options under consideration, which would replace between 6,000 and 12,000 lineal feet of existing fill in the delta with new bridges. Other project improvements that will be evaluated in the EA include:
• Widening of I-5 to add one high-occupancy vehicle (HOV) lane in each direction from approximately Exit 111 to Exit 116
• Replacement of existing bridges and construction of new bridges across the Nisqually Delta to increase the resiliency of I-5 to flooding and sea level rise and to support habitat enhancements in the delta; bridge length design options are evaluated in this Environmental Assessment.
• Construction of a new grade-separated crossing of the BNSF Railway railroad tracks east of the Nisqually River.
• Realignment of McAllister Creek where it crosses below I-5 to improve tidal exchange, water quality, and habitat.
• Development of a shared-use path adjacent to I-5 to provide a new active transportation connectionbetween Lacey (Exit 111) and DuPont (Exit 118) and improved access to the Billy Frank Jr. Nisqually National Wildlife Refuge.
• Removal of two existing fish passage barriers under I-5 in the Red Salmon Creek drainage.
• Installation of facilities to treat stormwater runoff from I-5 within the study area.
• Improvements to habitat, including the creation of new habitat in areas where the existing I-5 embankment would be removed.
The project is located in Thurston and Pierce Counties.