GEOMORPHIC ROAD ANALYSIS AND SEDIMENT TRANSPORT MODELING IN THE LOWER STEAMBOAT AND CANTON CREEKS SUBWATERSHED, UMPQUA NATIONAL FOREST

The Umpqua National Forest spans 980,000 acres in the western region of the Cascade Mountains in southwest Oregon. It is home to the North Umpqua River, which is world-renowned for its native anadromous fish species, including chinook and coho salmon, and steelhead and cutthroat trout. Forest roads have been shown to alter the hydrologic and geomorphic processes of watersheds and can degrade the water quality of aquatic ecosystems through the introduction of fine sediment. The Geomorphic Road Analysis and Inventory Package, a suite of tools used to evaluate forest road impacts and risks, has been applied to study these relationships in the Umpqua National Forest. Since 2018, 400 miles of road have been surveyed, enabling targeted road restoration and decommissioning efforts. These surveys have also been instrumental in sediment transportation analysis on watershed restoration projects, including the Lower Steamboat and Canton Creeks subwatershed. As climate change continues to affect Pacific Northwest forests through temperature variability and increased wildfire prevalence, it is important to ensure road sediment does not further contribute to the deterioration of riparian ecosystem health and stability in the North Umpqua.