Green Island and the Hyporheic Zone: Why Restoration Matters

Large river floodplains present diverse benefits to communities, yet management strategies often fail to consider the broad suite of ecosystem services they provide. The U.S. Environmental Protection Agency (EPA) is evaluating the benefits associated with restoring large river floodplains, with emphasis on the benefits of levee setbacks and revetment removals. This effort will provide scientific support for community-based environmental decision making within our study area on the McKenzie River, a tributary to the Willamette River in Oregon, and support emerging restoration efforts along the Yakima River in Yakima, Washington, and across the nation. The EPA is working with the McKenzie River Trust, the City of Yakima, and the Washington Department of Transportation to bring a more holistic approach to enhance sustainability, with consideration of the ecosystem services offered by dynamic river systems. Restoring hydrologic connectivity in floodplains can enhance the overall ecological condition of riparian systems. We have examined groundwater flow patterns, denitrification rates, and water isotopic signatures for identifying water sources at Green Island, a 1,100 acre restoration effort located at the 1 U.S. Environmental Protection Agency, Region 10, Seattle, WA 98101, United States 2 U.S. Environmental Protection Agency, National Risk Management Research Laboratory, Ada, OK 74820, United States 3 U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Corvallis, OR 97333 United States