Nisqually Delta

The Nisqually River Delta is located south of the City of Lakewood. Interstate 5, the major north-south connector through the state, was built over the delta. A major weather event in 1996 flooded this corridor, revealing vulnerabilities that must be addressed. Two significant environmental issues face the delta: The health of salmon and risk of flooding.

Addressing a problem

If the region experiences a major weather event, Interstate 5 may be compromised by flood. There are also indicators taht the wandering riverbend at Wah-He-Lut will encroach on the interstate within the next 20 years. Salmon populations are also suffering, as the areas where salmon typically acclimate to seawater are shrinking and desalinating.

The Nisqually Indian Tribe and the City of Lakewood, among other agencies, hired the U.S. Geological Survey to examine the delta. The survey determined that under normal conditions Interstate 5 may be compromised within 20 years. That timeline could be shorter if an avulsion event from a flood or sudden acceleration of erosion occurs.

To reconstruct I-5 through the delta may cost roughly $4 billion, which would be among the most expensive infrastructure projects in state history.

The City of Lakewood, the Nisqually Indian Tribe, and the South Sound Military & Communities Partnership (SSMCP) all support legislative action to prepare for the redesign and reconstruction of this section to respond to environmental and structural issues looming ahead.