Federal review says large Donlin tailings dam failure could leave Crooked Creek uninhabitable

The U.S. Army Corps of Engineers on Sept. 23 released a draft review that, for the first time, models large failures of the tailings dam planned for the Donlin Gold mine. In the worst cases, it finds, the village of Crooked Creek would likely no longer be habitable. The Corps also says a failure of any size "remains extremely unlikely."

A federal judge ordered the new analysis. The Corps' 2018 environmental review modeled a spill of only 0.5 percent of the mine's tailings facility, where mining waste would be stored behind the dam. The Orutsararmiut Native Council and other tribes sued, and in September 2024 U.S. District Judge Sharon Gleason found the agencies erred "by failing to consider a tailings spill larger than 0.5%" of the facility's volume. In June 2025, she sent the decision back to the agencies without canceling the mine's permits. Her order does not bar construction, but it requires 90 days' notice to the parties and the court before construction under the permit or right-of-way begins during the review.

The draft now models three larger spills, releasing 5.4, 13.3 and 27 percent of the tailings facility. In the largest, tailings and water would pour from behind a planned 471-foot dam about 10 miles above Crooked Creek. The flood would reach Crooked Creek in about an hour and a half, Chuathbaluk in about nine and a half hours, Aniak in under 15 hours and Kalskag in about 22, and sooner at Chuathbaluk and Aniak during flood season. The Kuskokwim River would rise 11.1 feet just below the Crooked Creek confluence and about 2 feet at Chuathbaluk and Aniak.

Even the smallest of the new scenarios would require evacuating parts of Crooked Creek. In the middle scenario, tailings could lie 3 to 30 feet deep in places, and the draft finds the village would likely no longer be habitable. In the largest, the airstrip would flood completely, tailings would reach 10 to 30 feet deep, and the draft says the potential for loss of life would increase. The draft's executive summary describes the largest scenario more narrowly, saying it could make parts of the village uninhabitable.

The draft also finds that larger spills could harm fish populations in Crooked Creek for years to decades, with the largest potentially causing effects lasting generations. Thousands of acres of wetlands would be buried or eroded, with recovery taking decades to more than a century. Farther downstream, the Kuskokwim's volume is expected to dilute contaminants. The Bureau of Land Management found the project may significantly restrict subsistence in parts of the project area, which requires formal subsistence hearings alongside the Corps meetings.

The Corps bases its view that a failure is extremely unlikely on the dam's design: a bedrock foundation, rockfill and a construction method it associates with the lowest failure rates in the world. It says no known dam sharing all of those traits has failed. The state Dam Safety Program would oversee the dam and requires a public emergency action plan.

Donlin Gold is owned by NovaGold and investment funds managed by Paulson Advisers. The mine site is on land selected by Calista Corp. and The Kuskokwim Corp.

Public comment is open through Oct. 23. Hearings are scheduled in Bethel on Oct. 14 from 2 to 6 pm, in Crooked Creek on Oct. 15 from 1:30 to 3:30 pm, in Aniak on Oct. 16 from 11 am to 2 pm, and online Oct. 19 from 6 to 8 pm. The Corps and the Bureau of Land Management will then decide, by May 28, 2027, whether to modify, reaffirm or rescind the mine's permit and right-of-way. Comment and hearing details are posted at donlingoldseis.com.