Geomorphology

The USGS documents historical and current channel and floodplain processes and conditions to assist management and regulatory agencies in evaluating restoration proposals and designing effective restoration and monitoring strategies for the Sprague River and its principle tributaries. The study involves multiple analyses, including assessments of historical channel change, riparian and floodplain...

Each autumn Fall Creek Lake is drawn down to allow endangered juvenile salmonids to pass freely through the dam. The drawdowns involve lowering the lake water level to the lake bed, creating a fluvial environment characterized by large amounts of sediment being transported through the dam and into Fall Creek and the Middle Fork Willamette River.

Marmot Dam on the Sandy River was removed in 2007 as part of decommissioning of Portland General Electric’s Bull Run Hydroelectric Project. Removal of the 15-meter-tall dam would allow the Sandy River to flow freely for the first time in nearly 100 years and make upstream habitat more accessible to anadromous fish.