Merced River Restoration in Yosemite Valley

The Merced River in Yosemite Valley is one of the most popular recreation spots in the country. It was added to the National Park Service (NPS) National Wild and Scenic Rivers System in 1987 for its free-flowing condition, water quality, and outstandingly remarkable values. However, the river has been negatively impacted by historic and ongoing human activity. Riparian corridors have been impacted, and other riverbank segments suffer from severe erosion, riprap, or trampling by visitors. This project’s objectives? Restore a more complex and dynamic river and tributary channels, encourage more frequent overbank flooding and off-channel flows, and restore the riparian zone.

Since 2015, we’ve been providing scientific, design, and construction support to the NPS for the restoration of 2.95 miles (4.75 kilometres) of the Merced River. During this time, we’ve worked with a team led by the University of California, Santa Barbara (UCSB) to characterize the condition and underlying causes of river impairment and use this characterization to guide a 10-year, multi-phase restoration strategy. We’ve carried out detailed site inventories and mapping of the stream channel, riverbank, and riparian corridor vegetation, identified short- and long-term holistic actions, developed a 2-D hydraulic model, and provided design and construction oversight for eight projects in Yosemite Valley.

This project has been driven by the NPS’s Merced Wild and Scenic River Final Comprehensive Management Plan and Environmental Impact Statement, which guides the protection and enhancement of the river values and manages use for the next 20 years. With these restoration efforts, we’re working to support public use and enjoyment of this important landscape for decades to come.