USGS - science for a changing world

USGS Science to Support the Elwha River Restoration Project

Home Who We Are What We Do Products Publications News Contacts

Elwha in the News


Photo from the sky looking down on a river cutting through a cliff with a dismantled dam structure.Moving Mountains: Elwha River Still Changing Five Years After World’s Largest Dam-Removal Project: More than 20 million tons of sediment flushed to the sea

Starting in 2011, the National Park Service removed two obsolete dams from the Elwha River in Olympic National Park, Washington. It was the world’s largest dam-removal project. Over the next five years, water carrying newly freed rocks, sand, silt and old tree trunks reshaped more than 13 miles of river and built a larger delta into the Pacific Ocean.
By Andy Ritchie, Jonathan Warrick, and Leslie Gordon
USGS News Release Sept. 5, 2018 [read the entire story]


USGS partnership with Lower Elwha Klallam Tribe featured in new fact sheet on Elwha River dam removals

Aerial photo looking at the mouth of a river with sand bars, land surrounding the river is covered with trees and other vegetation.The USGS has published a new Fact Sheet, “Science Partnership between U.S. Geological Survey and the Lower Elwha Klallam Tribe: Understanding the Elwha River Dam Removal Project.” Two large hydroelectric dams on the Elwha River in Washington State were removed in the period 2011–2014 to restore the river ecosystem and recover imperiled salmon populations. The new fact sheet summarizes findings by a multidisciplinary team of scientists from the Lower Elwha Klallam Tribe, the USGS, other agencies, universities, and non-governmental organizations who collected data before, during, and after dam removal. The 4-page fact sheet lists key lessons, details some impacts of dam removal on river sedimentation and the physical and biological makeup of the estuary and coast, and lists references with in-depth information. Contacts: Jeff Duda,, 206-526-2532; Jon Warrick,, 831-460-7569

Aerial photographs of the Elwha River mouth before and during dam removal. Photograph A by Ian Miller of Washington Sea Grant, B by Jonathan Felis of USGS, and C by Neal and Linda Chism, volunteers with LightHawk.“Largest Dam Removal in U.S. History Scientifically Characterized”

The effects of dam removal are better known as a result of several new studies released this week by government, tribal and university researchers. The scientists worked together to characterize the effects of the largest dam removal project in U.S. history occurring on the Elwha River of Washington State. New findings suggest that dam removal can change landscape features of river and coasts, which have ecological implications downstream of former dam sites.
By Jonathan Warrick and Paul Laustsen
Feb. 17, 2015

“Elwha Sediment Detailed in New Document”

As the largest dam-removal project in history moves into its third year, scientists from the U.S. Geological Survey released a new report that documents the movement of sediment down the Elwha River in Washington State.
By Christopher Magirl and Paul Laustsen
Feb. 11, 2014

USGS hydrologic technician James Foreman operates an electronic deployment reel from a bridge over the Elwha River, Washington.“Sediment Muddies the Water”

The largest dam-removal project in history has increased river water cloudiness caused by suspended particles, known as turbidity, a process that could affect aquatic life. The dismantling of two large dams on the Elwha River in Washington began in September of last year and has increased river turbidity significantly, even though most of the sediment trapped behind the dams has yet to erode into the river. These findings appear in the first published report on sediment response to the Department of Interior’s Elwha River Restoration Project.
By Jonathan Warrick and Helen Gibbons
October 23, 2012

A female Chinook salmon, among the first wave of fish to recolonize waters that haven’t had salmon in 100 years, excavates a nest inside Olympic National Park.“Elwha: One Year Later”

One year after crews began to take down two obsolete dams on Washington state’s Elwha River, the unprecedented restoration is already yielding such signs of life as fish hatchlings, tree saplings and the beginnings of beaches for ongoing study by US Geological Survey scientists and their state, federal and tribal partners.
By Barbara Wilcox
Sept. 28, 2012
USGS Top Science Feature

Older USGS Newsroom articles:

Underwater Ecosystem Inundated by Sediment Plume: Dive Teams Continue Underwater Study at Mouth of Elwha River”
July 27, 2012

Elwha River Restoration Science Explained at Science Symposium
September 13, 2011

Publications Explain Elwha River Restoration to Scientists, General Public
September 7, 2011

Final Beach Erosion Survey of the Elwha River Delta Before Dam Removal
August 25, 2011

Federal Dive Teams Conduct Underwater Study at Mouth of Elwha River
August 4, 2011

Restoration of Native Mammal Continues in Olympic National Park as Biologists Prepare to Reintroduce 15 Fishers This Weekend
December 17, 2008

Before the Dams Come Out: Scientists Measure Elwha River Conditions Now to Help Measure Dam Removal Success Tomorrow
September 15, 2008

Biologist-Divers Complete 42-Mile Snorkel Survey of Elwha River
September 21, 2007

USGS Sound Waves

USGS researchers Raegan Huffman, left, and Chris Curran retrieve instrumentation to measure sediment concentration from the Elwha River, Washington, on April 2, 2012, during the incremental removal of two large dams from 2011 to 2013. USGS photograph by Jon Czuba.Scientific Portrait of the Largest Dam Removal in U.S. History

Five peer-reviewed papers, with authors from the USGS, the Bureau of Reclamation, the National Park Service, Washington Sea Grant, National Oceanic and Atmospheric Administration (NOAA) Fisheries, the Lower Elwha Klallam Tribe, and the University of Washington, provide detailed observations and insights about changes in the river’s landforms, waters, and coastal zone during the first 2 years of dam removal. During this time, massive amounts of sediment were eroded from the drained reservoirs and transported downstream through the river and to the coast.
By Jonathan Warrick and Paul Laustsen
January / February 2015

Photo of Amy giving talk.Undamming Washington’s Elwha River—Public Lecture on Largest Dam Removal in U.S. History

The largest dam removal in U.S. history was the subject of a public lecture by USGS research geologist Amy East on February 26, 2015, at the USGS campus in Menlo Park, California. East described changes to the landscape caused by the removal of two large dams—the 32-meter-tall Elwha Dam and the 64-meter-tall Glines Canyon Dam—from the Elwha River in Washington State. This was the largest dam removal ever undertaken, both in terms of the dams’ heights and in terms of how much sediment had accumulated behind them.
By Helen Gibbons
January / February 2015

Glines Canyon Dam in the process of being removed. Courtesy of Elwha Dam Removal Begins—Long-Planned Project Will Restore Ecosystem, Salmon Runs

The largest dam-removal project in U.S. history—the Elwha River Restoration Project—commenced during the second week of September 2011, when National Park Service contractors began to dismantle two dams on the Elwha River in Washington State. The 32-m-tall Elwha Dam and the 64-m-tall Glines Canyon Dam, completed in 1913 and 1927, respectively, have been blocking the natural supply of sediment to the lower river and coast and severely limiting salmon and steelhead spawning for nearly a century. In a ceremony celebrating the beginning of the Elwha River restoration, Secretary of the Interior Ken Salazar praised the project, saying, "America's rivers are the lifeblood of America's economy—from the water for farms that produce our food to the fish and wildlife that sustain our heritage." He added that restoration will help support the culture of the Lower Elwha Klallam Tribe, who have lived along the river for centuries.
By Jon Warrick
November / December 2011

Andrew Schwartz, Washington State Department of Ecology, holds a data collector that logs his position (latitude, longitude, and elevation) as he maps the beach along preplanned transects from just landward of the primary dune crest to the waterline. His backpack holds a GPS receiver and antenna.Final Beach-Erosion Survey of the Elwha River Delta Before Dam Removal

On August 26-27, 2011, the U.S. Geological Survey (USGS) conducted its final beach-erosion survey of the Elwha River delta before a historic dam removal began upstream in September. The survey is part of an ongoing study of how damming has affected the ecosystem.

Two dams on the Elwha River—the Elwha and the Glines Canyon—have stopped most of the flow of sediment to the beaches on its delta for nearly 100 years. Historical photographs and topographic-survey data document severe erosion on these beaches, corroborated by 7 years of Global Positioning System (GPS) beach surveys conducted on foot and with personal watercraft by the USGS in collaboration with the Lower Elwha Klallam Tribe and the Washington State Department of Ecology.
By Jon Warrick
September / October 2011

The New York Times

Aerial photograph of the mouth of the Elwha River taken in June 2014, bu Andy Ritchie, NPS.“When Dams Come Down, Salmon and Sand Can Prosper”

When people urge the removal of dams they say are strangling rivers in the West, it’s usually fish they’re worried about. Studies of dam-removal projects show that migratory species like salmon respond quickly to improved conditions once a dam is removed.
But the removal of a dam on the Elwha River in northern Washington State — the largest such project in the United States — is demonstrating that there can be another beneficiary: the beach.
By Cornelia Dean
New York Times staff reporter

Photograph of Elwha Dam removal, by Kevin P. Casey, Reuters.“A river newly wild and seriously muddy”

PORT ANGELES, Wash. — The Elwha River drains out from Olympic National Park, a pristine place in the world. And as recently as a year ago, the river looked the part: it babbled its final miles in water clear enough to see the bottom. Now it runs thick with grainy sediment the color of chocolate milk. But believe it or not, that is a good thing, or at least the roundabout result of one.
By Kirk Johnson
New York Times staff reporter
August 2, 2012

Photograph of Elwha Dam by Michael Hanson for the NY Times.“Removing Barriers to Salmon Migration”

OLYMPIC NATIONAL PARK, Wash. — Beginning late this summer, one of the most promising and pure acts of environmental restoration the region and the nation have ever seen will get under way here.
By William Yardley
New York Times staff reporter
July 29, 2011


Screenshot of video from Quest.“A River Returns”

In Washington state, a river once known for its abundant salmon run is getting a second chance. The Elwha River dams, which decimated salmon populations and profoundly altered the ecosystem, are coming down and hopes are high that salmon will return.
7-minute video story by Michael James Werner for QUEST Northwest
Oct 23, 2013

Beginning of page

KCTS EarthFix

Screen capture of the KCTS film.“Undamming the Elwha”

A 26-minute documentary film by Katie Campbell and Michael Werner that describes the Elwha project and the science activities taking place to track the restoration. This film was broadcast Nationwide on public television channels in April of 2012.

Washington Post

Lassiter Mill Dam on the Uwharrie River in North Carolina. AMERICANRIVERS.ORG“Elwha Dam removal illustrates growing movement”

The largest dam demolition in the nation's history will begin Saturday when an excavator claws away at the concrete supports for Washington's 108-foot Elwha River Dam, a ceremonial act of destruction that will signal not only the structure's demise but the latest step in a broad shift in the way Americans are managing rivers.
By Juliet Eilperin
Washington Post staff reporter
September 16, 2011

Beginning of page

The Seattle Times

“‘Elwha: A River Reborn’: the resurrection of a river”

In “Elwha: A River Reborn,” Lynda V. Mapes and Steve Ringman document the process of restoring 70 miles of pristine salmon spawning habitat by removing dams on the Olympic Peninsula’s Elwha River.
Book Review by Tim McNulty
May 6, 2013

“Kelp armageddon at the mouth of the Elwha”

There are winners and losers as the Elwha dam removal project underway transforms the Olympic Mountain watershed.
By Lynda Mapes
Seattle Times staff reporter
March 17, 2013

“Dam gone, nature rebuilds Elwha River beach”

After a 100-year retreat, the beach at the mouth of the Elwha River is making a comeback.
By Lynda Mapes
Seattle Times staff reporter
August 5, 2012

“The underwater world of the Elwha: a new ecosystem takes shape”

Divers took the plunge last week to investigate the effects on the nearshore environment of dam removal on the Elwha River.
By Lynda Mapes
Seattle Times staff reporter
July 31, 2012

“Sediment from Elwha River begins to enter sea”

The Elwha River plume entering the Strait of Juan de Fuca is full of sediment. The higher than normal concentration is a result of the largest controlled release of sediment into a river and marine waters in recorded history.
By Lynda V. Mapes
Seattle Times staff reporter
April 29, 2012

“On the Elwha, a lunar landscape emerges”

Not all of the sediment that has accumulated in the reservoirs will be released downstream. The former reservoir bottoms are emerging and during the early phases are creating a bare landscape. However, a large replanting with native plants by the NPS and Lower Elwha Klallam Tribe is planned and volunteer colonists are arriving on their own.
By Lynda V. Mapes
Seattle Times staff reporter

“Elwha River reborn as landscape transforms”

The Elwha River is re-emerging as Lake Aldwell and Lake Mills reservoirs are drawn down in preparation for the beginning of dam removal in September.
By Lynda V. Mapes
Seattle Times staff reporter

“Elwha River finding its natural channel once more”

Already, the Elwha River is starting to look, well, like a river again, as the $350 million federal restoration program, including taking out Elwha and Glines Canyon dams, continues.
By Lynda V. Mapes
Seattle Times staff reporter

Beginning of page

Smithsonian Magazine

“On the Elwha, A New Life When the Dam Breaks”

The nation's largest and most ambitious dam removal will begin this month, when workers start demolishing two antique dams on Washington state's Elwha River.
By Abigail Tucker
Smithsonian staff writer
September 15, 2011

“Preparing for a New River”

The turquoise, snow-fed Elwha River crashes through the cedar forests of Washington's Olympic Peninsula.
By Abigail Tucker
Smithsonian staff writer
December 2011

National Geographic

“Rebirth on the River: Washington’s Elwha Flourishing After Big Dam Removals”

The first signs of life are beginning to return to the Elwha River in Washington State, where the largest dam removal in U.S. history is nearly complete.
By Jason Jaacks
National Geographic Young Explorer
August 29, 2013

Beginning of page

KING 5 News

“Record rain provides research opportunity on Elwha River”

While many of us are running for cover during this record breaking weather week, some scientists are racing for their gear. History is happening on the Elwha River, where two dams were recently removed and heavy rain is creating research opportunities.
By KING 5 News
November 20, 2012

“Silt from Elwha River dam removal doesn't hang around, say scientists”

PORT ANGELES — Before the historic removal of two dams on the Elwha River, scientists studied all the plant and animal species they could. They wanted to know how a giant plume of silt from the removal project would affect them. Scientists returned to the Elwha Thursday to find out.
By Gary Chittim
KING 5 News

“World's largest dam removal project on the Elwha River”

NEAR PORT ANGELES, Wash. — When two large dams are removed after spending most of the last century altering flows on the Elwha River, the ecosystem will change. Article and 2-minute video from the nightly news broadcast.
By Gary Chittim
KING 5 News
August 8, 2011

Peninsula Daily News

“An undammed Elwha River building beaches again: Crab found where it once was too rocky”

PORT ANGELES — During a recent survey of sediment that flowed down the Elwha River and accrued along a beach to the east of the river mouth, Ian Miller found something he had not yet seen during his surveys.
By Jeremy Schwartz
Peninsula Daily News
October 14, 2013

“Chinook salmon returning to dam-less Elwha River”

OLYMPIC NATIONAL PARK — The 2013 fall chinook spawning season was one of the strongest since 1992, and the king salmon are moving into more new habitat in the Elwha River, according to fish biologists.
By Arwyn Rice
Peninsula Daily News
October 7, 2013

“Drones are Elwha dam researchers eyes in the sky”

PORT ANGELES — Electronic “Ravens” join hungry raptors, their eyes fixed on the flowing water below, as they swoop over the Elwha River this week. The 4½-foot-wide aircraft, resembling radio-controlled airplanes, are steered by researchers on the ground.
By Jeremy Schwartz
Peninsula Daily News
September 26, 2012

“Divers literally look into silt coming out of mouth of freed Elwha River”

When it comes to the Elwha River, appearances aren't always what they seem. That silt-laden, murky plume flowing through two deconstructed dams and their former lake beds has had minimal effect on the alluvial sea floor at the river's mouth.
Story, video, and gallery by Keith Thorpe
Peninsula Daily News
July 28, 2012

Beginning of page


Accessibility FOIA Privacy Policies and Notices

U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Laura Zink Torresan