US dam removals rise as states reconnect rivers and fish routes

In short: The United States is removing dams at a growing pace to reconnect rivers, help fish migrate, and improve river health.

What's going on

Removing dams, sometimes called “undamming,” is becoming a mainstream river restoration approach in the US. In 2025, more than 100 dams were removed across 30 states, reconnecting about 4,900 miles of waterways, according to The New York Times citing the group American Rivers.

This is part of a longer shift. Resilience reports that about 2,200 dams have been removed nationwide, with most removals happening in the last 25 years. It also says that since 2000, the US has removed more dams than it has built. NOVA has described the same pattern, noting that more than half of recorded removals happened in the last decade.

Many of the dams coming out are old, unsafe, or no longer worth the cost to keep running. Supporters say removing dams can make rivers cooler, cut down on algal blooms (fast-growing “pond scum” that can harm water quality), improve habitat for wildlife, and reopen routes for migratory fish like salmon.

A major example is the Klamath River project in the West. American Rivers says crews broke the final temporary barriers, called cofferdams (short-term walls used during construction), in August 2024. This completed the removal of four dams and reopened about 420 miles of salmon habitat that had been blocked for more than a century.

What to watch

Researchers and conservation groups say the country is entering a new era of dam removal, and they may push for bigger national goals. Some analysts also warn that dam removal alone will not stop the decline of freshwater wildlife, especially in rivers that still lack strong protections.

Source: NYTimes