Pendleton, OR -

A dam that blocks nearly 50 miles of prime fish spawning habitat on the Walla Walla River is slated for removal.

The dam is a gravel push-up dam. Efforts to remove them began in the 1990s. The Zell Ditch is one of the last.

The East Oregonian reports the dams impede the spawning paths of salmon.

Blockage during low flows meant stranding fish. In the case of chinook salmon, it meant wiping them completely out of the basin.

The Chinook were later saved by restoration work by the Confederated Tribes of the Umatilla Indian Reservation.

Zell Ditch serves 30 separate water rights claims, the oldest dating back to 1873.

Gravel push-up dams were used to steer water out of the river and support agricultural production along Walla Walla River Road.