Tri-Cities Causeway Removal to Restore Yakima River Ecosystem

In a move to restore the natural ecosystem of the Yakima River, the U.S. Army Corps of Engineers has awarded a $1.2 million contract to remove the causeway connecting Bateman Island to the Tri-Cities area. The causeway, built in the 1940s, has been restricting water flow and contributing to elevated water temperatures and degraded water quality in the river.

The warm, stagnant backwater created by the causeway has provided ideal conditions for non-native fish species, such as smallmouth bass, which prey on young salmon migrating to the ocean. This has had a devastating impact on the region's historic salmon and steelhead populations, which have plummeted from 500,000 to just 10,000 in the last century.

The removal of the causeway, scheduled to begin as early as December 2025, will allow the river to flow freely, improving water quality and restoring critical habitat for culturally significant fish species. "The island's causeway blocks the river's course, which negatively impacts critical habitat for culturally significant fish," said Lt. Col. Kathryn Werback of the Corps.

The project is a collaborative effort between the Corps, the Washington state Department of Fish and Wildlife, the Yakama Nation, the Washington state Department of Ecology, and the Mid-Columbia Fisheries Enhancement Group, all focused on reviving the river's ecosystem and supporting the recovery of salmon and other native fish populations.