Historic dam removal poses challenge of restoring both river and landscape

Standing on an outcrop of volcanic rock, Joshua Chenoweth looks across the languid waters of California’s Iron Gate Reservoir and imagines the transformation in store for the landscape. In early 2024, operators will open the floodgates on the 49-meter-high dam that blocks the Klamath River, allowing the more than 50 million tons of water it impounds to begin to drain. Once it’s gone, heavy equipment will dismantle the structure. All that will remain of the 11-kilometer-long reservoir that filled the valley for 60 years will be steep-sided slopes coated in gray mud, split once again by a free-flowing river. Within months, however, that sediment will be covered with a fine, green carpet of seedlings and colorful splashes of flowers, many planted by Chenoweth’s team. Eventually, if all goes as hoped, patches of Gary oak, desert gooseberry, and mock orange will take hold and a lush ribbon of cottonwood, willow, and ash trees will line the banks of the river. Beneath their boughs, salmon that last migrated through this valley more than a century ago will return. It bears the marks of a mythic creation story—a barren moonscape brought to life. But it’s tantalizingly within reach for Chenoweth, a restoration ecologist who has spent his career devising ways to transform once-submerged ground into thriving forests, meadows, and marshes. More than a decade ago, he oversaw efforts to restore native ecosystems in Washington’s Olympic National Park after two ...
Source: ScienceNOW - Category: Science Source Type: news