Simple hand-built structures can help streams survive fire and drought.

Low-tech restoration is gaining popularity as an effective solution for distressed waterways in the American West

Dressed in waders and work gloves, three dozen employees of the U.S. Department of Agriculture's Natural Resources Conservation Service stood near a small creek in the middle of the dry sagebrush of southeastern Idaho. The group was eager to learn how to fix a creek the old-fashioned way.

Folding his white cowboy hat, 73-year-old rancher Jay Wilde told the group that he grew up swimming and fishing at this spot, Birch Creek, all summer. But when he took over his parents' family farm in 1995, the creek was dry by mid-June.

Wilde realized that was partly because his family and neighbors, like generations of American settlers before them, had trapped and eliminated most of the beavers that built dams. Settlers also built roads, cut trees, logged streams, overgrazed livestock, and created flood control and irrigation structures, all of which changed the plumbing of watersheds like Birch Creek.

Many wetlands in the western United States have disappeared since the 1700s. California has lost an astonishing 90% of its wetlands, which include stream edges, wet meadows, and ponds. In Nevada, Idaho, and Colorado, more than 50 percent of wetlands have disappeared. Valuable wetland habitat is down to 2% of the arid West, and the remaining wetlands are in trouble.

Nearly half of America's streams are in poor condition, unable to fully support wildlife and people, says Jeremy Maestas, a sagebrush ecosystem specialist at NRCS, who organized this workshop on the Wilde Ranch in 2016. As communities across the American West face increasing water shortages, more frequent and larger wildfires (SN: 9/26/20, p. 12), and unpredictable flooding, restoring struggling streams becomes a necessity.

Landowners and conservation groups use volunteer and labor teams, like the NRCS group, to build inexpensive solutions from scraps of wood and stone. And the work is making a difference. Streams flow longer in summer, beavers and other animals are returning, and a study last December confirmed that landscapes irrigated by beaver activity can withstand wildfires.

Fill the sponge
Think of a floodplain as a sponge: Each spring, western floodplains soak up snow that melts from the mountains. The sponge is then wrung out in summer and fall, when the snow is gone and precipitation is scarce. The longer the water remains in the sponge, the more streams can flow and plants can thrive. A full sponge makes the landscape better equipped to deal with natural disasters, as wet places filled with green vegetation can slow floods, tolerate droughts, or delay flames.

According to Joseph Wheaton, a geomorphologist at Utah State University in Logan, modern stream restoration methods can cost about $500,000 per mile. The projects are often complex and involve excavators and bulldozers to shore up stream banks with giant boulders or to build brand new channels.

"Even though we spend at least $15 billion a year fixing streams in the U.S., we're just scratching the surface of what needs fixing," Wheaton says.

The big yellow machines are certainly needed to restore the big rivers. But 90 percent of all U.S. rivers are small streams, those that can be stepped over or waded across.

For small streams, artisanal restoration solutions work well, often for a tenth of the cost, Wheaton says, and can be self-sustaining once nature takes over. These low-tech approaches include building beaver dam analogs to entice beavers to stay and get to work, erecting small stone dams, or strategically piling mud and branches in a stream. The purpose of these simple structures is to slow the flow of water and distribute it across the floodplain to encourage plant growth and fill the underground sponge.

Wheaton says repairs like these cure a common ailment that plagues most western streams, including Birch Creek: human activities have turned these waterways into straight channels, largely free of debris. As a result, most streams flow too straight and too fast.

"They should be messy and inefficient," he says. "They need more structure, whether it's wood, rocks, roots or soil. That's what slows down the water." Wheaton prefers the term "riverscape" to stream or river, because he "can't imagine a healthy river without including the land around it."

Natural structures "feed the river a healthy diet" of natural materials, allowing soil and water to reaccumulate in the floodplain, he says.

Because 75 percent of the West's water resources are on private land, conservation groups and government agencies like NRCS help ranchers and farmers improve streams, springs or wet meadows on their property.

"In the West, water is life," Maestas says. "But it's a very limited resource over time. We try to keep what we have on the landscape as long as possible."