In the mountains of the American West, where snowmelt feeds rushing rivers and eventually flows to kitchen taps across the country, a 25-year-old rule has been quietly protecting clean drinking water for millions of people. Now, researchers are showing just how vital that protection really is.
A new study from the University of Washington and Conservation Science Partners, published in the journal PLOS Water, confirms that the 2001 Roadless Rule shields drinking water for 25 million Americans across more than 80,000 miles of rivers. The rule blocks development on 60 million acres of national forest land—an area roughly the size of Montana.
"The roadless rule supports the drinking water supply for 25 million Americans and offers critical protection of wildlife habitat and recreational assets. In short, rivers in roadless areas are essential for both people and nature," said lead author Julian Olden, a UW professor of aquatic and fishery science.
Forested lands act as natural water filters. Soil microbes and plant roots trap dirt, chemicals, and other pollutants before rainwater reaches rivers and eventually treatment facilities. This means cleaner water costs less to process, saving money for utilities and communities downstream—often hundreds of miles from the forests themselves.
"Forest cover is well recognized for generating economic benefits by avoiding the large capital costs of water treatment plants needed to ensure clean, safe drinking water for people," Olden said.
The researchers studied nearly 110,000 square miles of national forest containing 2,488 officially designated "roadless areas." They found that roughly 62,000 miles of river receive protection only from the roadless rule—with no other federal safeguards standing between those waters and potential development.
These protected rivers also serve as vital habitat for fish and wildlife. At-risk species like the bull trout rely on clean, undeveloped waters for spawning and raising their young. Hunters and anglers say roadless areas offer some of the best fishing and wildlife-watching opportunities left in the country.
The rule has faced political pressure. Last summer, the U.S. Department of Agriculture announced plans to rescind the roadless rule. More than 500,000 people submitted comments during the public comment period, and according to the Center for Western Priorities, over 99 percent opposed the change. Republican lawmakers also attempted to attach the repeal to wildfire prevention legislation.
Some argued that removing the rule would allow better forest management to fight fires. But most scientists disagree—research shows that building roads in roadless areas actually increases fire risk rather than reducing it.
"To be clear, the rule does not block any management action that supports forest health, wildfire mitigation or recreation," Olden said. "In fact, energy projects, transmission lines and mining development remain permitted within roadless areas."
The Forest Service says it is reviewing public comments and plans to publish a proposed rule and environmental impact statement later this year. For now, the rivers keep flowing, and for 25 million Americans, the water in their glasses starts in forests protected by a rule that has stood for a quarter century.