Green-Duwamish River named one of America’s Most Endangered Rivers of 2019

April 16, 2019

Outdated flood management threatens salmon, river health


Brandon Parsons, American Rivers, (512) 517-4001

Logan Harris, King County Dept. Natural Resources and Parks, (206) 477-4516

Doug Osterman, Green/Duwamish & Central Puget Sound Watershed (WRIA 9),

(206) 477-4793

Cathy Cochrane, Puget Sound Partnership, (360) 790-7958

Mindy Roberts, Washington Environmental Council, (206) 631-2600

Washington, D.C. – American Rivers today named the Green-Duwamish River among America’s Most Endangered Rivers® of 2019, citing the grave threat that outdated flood management poses to chinook salmon and river health. American Rivers and its partners called on the King County Flood Control District to develop better plans that protect people and property, as well as the salmon runs vital to endangered southern resident killer whales.

“The America’s Most Endangered Rivers report is a call to action to save rivers that face a critical decision in the coming year,” said Brandon Parsons with American Rivers. “Outdated flood management on the Green-Duwamish not only puts communities at risk, it’s harming our salmon and orcas.”

“We are already feeling the impacts of climate change in the Pacific Northwest, including higher temperatures and bigger floods, and it’s only going to get worse. Abusing and degrading our rivers will make us more vulnerable to these threats. Protecting and restoring the river will make us better prepared to face future floods and safeguard communities. It’s our choice to make.”

The King County Flood Control District has initiated development of a flood hazard management plan, which in its current form would result in a larger and more extensive levee system. This, in turn, would result in further loss of critical habitat and almost certain continued decline of salmon. Chinook salmon are vital to local tribes and communities and critical to the diet of endangered orca whales. The already extensive levee system dramatically decreases the number of shade-giving trees along the river, which negatively impacts water quality. The levees also separate the Lower Green River from 82 percent of its historic floodplain, reducing salmon rearing habitats and turning the lower river into a constricted canal that shoots juvenile fish into the heavily contaminated Duwamish estuary.

Current flood management is inadequate to protect local communities from existing flood risks and climate change is only going to increase those risks as winter storms will bring more rain and less snow.

American Rivers and its partners called on the King County Flood Control District to select community supported alternatives that will improve flood management and significantly increase salmon habitat.  The King County Flood Control District must strengthen the plan by defining integrated goals, maximizing the number of levee setbacks to increase flood storage capacity and salmon habitat, and offering clear habitat restoration actions to address the critical needs of salmon rearing habitat and riparian shade in the Lower Green River.

“We are at a crossroads for the Green-Duwamish River. Returning salmon face lethal water temperatures, southern resident orca are critically endangered and tribal treaty rights are at risk,” said King County Executive Dow Constantine. “Our changing climate raises the urgency of actions to reduce flood risks to our residents and economy, while restoring the natural systems we have so degraded. We can and must pursue solutions that meet all of these needs. The days of 1950s, single-purpose flood control are over.”

“The continued polluted condition of the Green-Duwamish River impacts not only the health of the ecosystem and all the creatures that depend on it, but also the health of the people and communities along its banks, many of them low-income,” said Sheida Sahandy, Executive Director at the Puget Sound Partnership. “Recovering the Green Duwamish has long been a goal for many community groups, as well as state and federal water quality managers. We can wait no longer to ensure that projects to improve habitat, water quality and human wellbeing get the needed policy and funding support to make recovery of this river successful.”

“The Lower Green is a major bottleneck to salmon recovery because juvenile salmon born in up-river areas do not have nearly enough habitat to rear as they move down river,” said Doug Osterman with the Green/Duwamish & Central Puget Sound Watershed (WRIA 9). “Creating salmon rearing habitat is one of the most important actions to be taken to recover the chinook salmon population of the Green River which, in turn, will provide more food for Puget Sound killer whales.”

The Green River flows unimpeded for 30 miles through forested mountains before reaching two dams: Howard Hanson Dam, a U.S. Army Corps of Engineers flood control facility, and Tacoma Headworks Diversion Dam for the city of Tacoma’s drinking water supply. Roughly half of the currently inaccessible historic habitat for salmon and steelhead lies above these dams. Downstream of the dams, the river provides some of Puget Sound’s best salmon and steelhead spawning habitat as it flows through forests, farms and the scenic Green River Gorge. At the city of Auburn, the river transforms into a channelized urban river with limited natural habitat. As the river approaches Seattle, it becomes the Duwamish River. The tidally-influenced Duwamish River provides critical nursery habitat for young salmon and a historically rich estuary before emptying into Elliot Bay and Puget Sound.

The annual America’s Most Endangered Rivers® report is a list of rivers at a crossroads, where key decisions in the coming months will determine the rivers’ fates. Over the years, the report has helped spur many successes including the removal of outdated dams, the protection of rivers with Wild and Scenic designations, and the prevention of harmful development and pollution.

The Green-Duwamish River was previously included on this list in 2016. Other rivers in the region listed as most endangered in recent years include the Willamette River (2019), South Fork of the Salmon River (2019 and 2018), South Fork Skykomish River (2017) and Green-Toutle River (2017).

America’s Most Endangered Rivers® of 2019

#1 Gila River, New Mexico
Gov. Grisham must choose a healthier, more cost-effective way to provide water to agriculture than by drying up the state’s last major free-flowing river.

#2 Hudson River, New York

The U.S. Army Corps of Engineers must consider effective, nature-based alternatives to storm-surge barriers that would choke off this biologically rich tidal estuary.

#3 Upper Mississippi River, Illinois, Iowa, Missouri

State and federal agencies must enforce laws that prohibit illegal levees, which increase flood risk for communities and degrade vital fish and wildlife habitat.

#4 Green-Duwamish River, Washington

Local leaders must produce a flood protection plan that safeguards communities and restores habitat for chinook salmon — fish that are essential to the diet of Puget Sound’s endangered orca whales.

#5 Willamette River, Oregon

The U.S. Army Corps of Engineers must immediately improve 13 dams to save wild chinook salmon and steelhead from going extinct.

#6 Chilkat River, Alaska

The Japanese investment firm, DOWA, must do the responsible thing and back out of a mining project that could decimate native salmon.

#7 South Fork Salmon River, Idaho

The U.S. Forest Service must safeguard endangered fish by denying a mining proposal that could pollute this tributary of the Wild and Scenic Salmon River.

#8 Buffalo National River, Arkansas

Gov. Hutchinson must demand closure of an industrial hog-farming facility that pollutes groundwater and threatens endangered species.

#9 Big Darby Creek, Ohio

Local leaders must use state-of-the-art science to craft a responsible development plan that protects this pristine stream.

#10 Stikine River, Alaska

The International Joint Commission of the United States and Canada must protect the river’s clean water, fish and wildlife, and indigenous communities by stopping harmful, polluting mines.

2019’s “River of the Year”: Cuyahoga River, Ohio

American Rivers celebrates the progress Cleveland has made in cleaning up the Cuyahoga River, fifty years since the river’s famous fire that sparked the nation’s environmental movement.


American Rivers believes every community in our country should have clean water and a healthy river. Since 1973, we have been protecting wild rivers, restoring damaged rivers and conserving clean water for people and nature. With headquarters in Washington, D.C., and offices across the country, we are the most effective river conservation organization in the United States, delivering solutions that will last for generations to come. Connect w