A historic fire lookout in Utah’s Ashley National Forest. Nearly 60% of the total river length within the forest is protected by the roadless rule, contributing to the water supply for Salt Lake City, Las Vegas, Los Angeles and San Diego. Photo: U.S. Forest Service

Approximately 90% of the U.S. population relies on public water systems. A significant portion of the water supplying those systems comes from forested lands, which means that policies impacting forests also impact our water access.

In 2001, the Clinton administration passed the Roadless Area Conservation Rule, blocking 60 million acres of national forest land from development to limit industrial timber harvest and preserve forest ecosystems. Although popular with the public, the roadless rule drew immediate criticism from timber and related industries. Last summer, the federal government announced plans to rescind it.

A new study from the University of Washington and Conservation Science Partners, published July 15 in PLOS Water, highlights the potential consequences of losing those protections by mapping how the roadless rule protects rivers.

“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.

State-level estimates of river length protected by roadless areas where the roadless rule is either the primary (blue) or a contributing (orange) measure of protection. Photo: PLOS/Olden et al.

To show how forests impact freshwater, the researchers looked at nearly 110,000 square miles of national forest representing 2,488 officially designated “roadless areas.” They cross-referenced the roadless areas map with a recent study assessing river protections nationwide to see where rivers and roadless areas overlap, and therefore which rivers were vulnerable to losing protection.

The researchers found that more than 80,000 miles of rivers in the continental U.S. receive some protection from the roadless rule. Of those protected segments, nearly 62,000 miles of river are protected by only the roadless rule. That water reaches 25 million people across the country, often at downstream distances far from roadless areas.

Research shows that forested lands provide higher quality water because soil microbes and plant roots filter contaminants before water arrives at treatment facilities. Cleaner water requires less processing, reducing potential treatment costs for public utilities. Some water utilities are investing in watershed protection as a way to save money and limit chemical use as demand for water rises.

“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,” said Olden.

Aerial View of Horseshoe Basin in the Pasayten Wilderness on the Okanogan Wenatchee National Forest in Washington’s Cascades, an area protected by the 2001 roadless rule. Photo: U.S. Forest Service

Roadless areas are also vital strongholds for sensitive aquatic species, Olden added. At-risk species such as the bull trout use protected habitat for spawning and raising young. Hunters and anglers also value roadless areas because they support such productive fish and wildlife habitat and offer unparalleled opportunities for outdoor recreation.

After the U.S. Agriculture Secretary Brooke Rollins announced the plan to rescind the roadless rule last year, more than half a million people submitted comments during the public comment period, which ended in September. According to the Center for Western Priorities, more than 99% of those comments expressed opposition to the plan.

Earlier this year, Republican lawmakers attempted to push the measure through by attaching it to the Wildfire Prevention Act, which supports prescribed burns and forest thinning to fight megafires. Their initial argument to justify clawing back protections claimed that rescinding the roadless rule would allow for better forest management, but most scientists disagree. Research shows that roadbuilding in formerly roadless areas is more likely to increase fire risk.

“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.”

Roadbuilding and logging can cause sediment build up in lakes and rivers, which must be filtered out. Chemicals from construction can also end up in the water supply. Reductions in forest cover resulting from rescinding the roadless rule may compromise water quality in the U.S., among other negative consequences for animals and ecosystems.

The U.S. Forest Service says it is reviewing public comments and plans to publish a proposed rule and draft statement of environmental impact this year.

“Any decision to rescind or downgrade the roadless rule that may put forested lands at risk requires careful consideration of the numerous benefits they offer to people and nature,” said Olden. “Our study offers data to inform such decisions.”

This study was funded by the University of Washington and from a contract from American Rivers to Conservation Science Partners.

For more information, contact Olden at olden@uw.edu.