Sediment Work Scheduled for Upper Lake Mills Delta

Date: August 11, 2010
Contact: Barb Maynes, 360-565-3005

With removal of the two Elwha River dams set to begin next year changes are coming to Olympic National Park's Elwha Valley. A culvert replacement project to allow fish passage at Griff Creek is nearly complete, and several other projects are slated to begin later this month.

Beginning on August 26, contractors will begin moving heavy equipment to the south end of the Lake Mills reservoir. The equipment will be used to remove trees and create a pilot channel through the extensive delta at the head of the reservoir.

The Lake Mills reservoir, along with nearby trails and an upstream section of the Elwha River within Olympic National Park will close to all boating for approximately eight weeks beginning on August 26.

The delta, created by the river's sediments as they flow downstream, has become overgrown in recent years by a large number of alder trees. As the trees and root systems have grown, the delta has become more stable and less easily eroded by the river. This project will help maximize erosion through the delta before, during and after dam removal.

"Once dam removal begins, the river will carry large amounts of sediment downstream where it will restore fish habitat, shellfish beds and beaches along the Strait of Juan de Fuca," said Karen Gustin, Olympic National Park Superintendent. "Creating a pilot channel and removing trees from the delta will give the river the head start that it needs to erode the sediment."

As the reservoir levels drop during and after dam removal, the river will naturally erode and carry downstream the sediments that have accumulated in the reservoirs, replenishing downstream spawning beds and the estuary and beaches at the river's mouth.

The entire Lake Mills reservoir and the Elwha River between Goblins Gate and Lake Mills will be closed to boating. Kayakers using the River will need to exit the river at Goblins Gate and hike out the Rica Canyon Trail and Elwha River Trail to the Whiskey Bend Trailhead.

The Lake Mills boat launch, boat launch access road and the West Lake Mills Trail and the Upper Lake Mills Trail will also close during this period.

"We ask for the public's patience during this period and regret any inconvenience that may be caused by this closure," said Olympic National Park Superintendent Karen Gustin. "This project must be finished before the fall rains arrive so we can maximize winter erosion, accomplish the work safely and be prepared for dam removal to begin next year."

In addition to removing trees and creating a pilot channel through the middle of the delta, workers will reposition logs within the river and reservoir to help redirect the river towards the new pilot channel. The likelihood of floating and submerged logs within the existing river channel and reservoir, along with heavy equipment at work, necessitate the boating closure. 

Removing of the two dams on the Elwha River will begin next year, setting in motion one of the largest restoration project in U.S. history. The Elwha River Restoration project includes:

Removing Elwha & Glines Canyon Dams
The largest dam removal in U.S. history will free the Elwha River after 100 years. Salmon populations will swell from 3,000 to more than 300,000 as all five species of Pacific salmon return to more than 70 miles of river and stream.

Renewing a Culture
The returning salmon and restored river will renew the culture of the Lower Elwha Klallam Tribe, who have lived along the Elwha River since time immemorial. Tribal members will have access to sacred sites now inundated and cultural traditions can be reborn. The NPS and the Tribe are primary partners on this project.

Restoring an Ecosystem
This project creates a living laboratory where people can watch and learn what happens when salmon return after a century to a still wild and protected ecosystem. The return of fish will bring bear, eagles, and other animals back to an ecosystem that has been deprived of this food source for a century.

Economic Benefits
Just as the dams played a vital role in the history and development of the area, removing them will create new opportunities for growth and regional vitality.

Restoring the Coast
Removing the dams will reestablish the natural flow of sediment from the mountains to the coast— rebuilding wetlands, beaches and the estuary at the river's mouth.