About the Project

Bateman Island sits at the confluence of the Yakima and Columbia Rivers. Since 1939, it has been connected to the city of Richland, Washington by an earthen and boulder causeway that is 550 feet long, 50 feet wide, and 40 feet tall. It was built without permits on state land, most likely to allow cattle grazing on the island.

The causeway prevents river flow around the south side of Bateman Island, creating a huge stagnant pool at the mouth of the Yakima that warms in the summer and fall, creating a thermal barrier to migrating adult sockeye. The blockage is sometimes so severe as to cut off migration, causing significant numbers of sockeye to die before reaching their spawning grounds. The warm, stagnant water welcomes exotic predatory fish, such as small mouth bass, that feed on juvenile salmon and steelhead moving downstream; it also enables toxic algal blooms and other invasive plant growth that impair water quality.

Removal of the causeway is seen as critical to restoring salmon runs in the Yakima Basin and improving water quality in the Yakima Delta, making it a high priority in the Yakima Basin Integrated Plan. Removal is also important to cultural salmon restoration efforts of the Yakama Nation and the Confederated Tribes of the Umatilla, who are actively engaged in the project.

The U.S. Army Corps of Engineers—approved to plan, design, and build modifications—will address recreational access to the island, likely through a bridge, and impacts to a nearby marina.