An explosion Saturday should demolish the final 50 feet of the Glines Canyon Dam on the Elwha River in Olympic National Park.

The work on the dam was postponed last October because of sediment clogging the Elwha water treatment plant, which supplies the city of Port Angeles.

The park superintendent, Sarah Creachbaum, told the Peninsula Daily News a $3.8 million upgrade to the plant will enable it to handle the sediment.

The dam once stood 210 feet tall. It's being removed in a $325 million project to restore the river as salmon habitat. The 108-foot Elwha Dam came down in March 2012.

The project should be completed in September 2014. Dam-removal work can proceed while the park is shut down to visitors because the money has already been appropriated.