INTRODUCTION Like many fluvial ecosystems of the United States the Willamette Valley has undergone numerous environmental changes since the introduction of man. Our impact on the environment was largely unrealized by the scientific community until the negative effects of our actions became readily apparent in the river ecosystems in the form of declining water quality, which in turn damaged faunal and floral diversity within the fluvial systems expounding the already decreasing fluvial health. CONCLUSIONS River restoration practices are becoming more and more important as scientists study the negative impacts of our previous river engineering projects, forest practices, and fisheries management. Marmot dam is the largest dam removal project undertaken in the state to date. Studies conducted on the after effects and how well the river system and fishery recovers will likely influence future dam removal projects on other rivers in the state. Our understanding of the complexities of river systems is increasing, which in turn is progressing our capabilities to prevent further damage on future projects and mitigation strategies to repair previously damaged areas. Figure 5. (ODFW, 2004) REFERENCES CITED Portland General Electric, 2008, Marmot Dam: Internet Web Resource, URL: Oregon Department of Fish and Wildlife, 2008, Water Quality and Quantity Program: Internet Web Resource, URL: Oregon Department of Fish and Wildlife, 2008, Fish Programs and Plans: Internet Web Resource, URL: Wohl, E., and others, 2005, River Restoration: Water Resources Research, VOL. 41, W10301, doi: /2005WR003985, 2005 Wolh, Ellen, 2006, Human Impacts to Mountain Streams: ScienceDirect Geomorphology xx (2006) xxx-xxx. Landuse and River Restoration in the Willamette Basin: Linkage Between River Management, Geomorphic Process, and Salmonid Recovery Prepared by: Patrick Stephenson ES 473 Environmental Geology Figure 4. (ODFW, unknown year) Table 1. (Wohl, 2005) ABSTRACT The Willamette Valley is set in a dynamic landscape characterized by mountainous river systems, recreational water ways, a world renowned sport fishery, and prosperous agriculture. If these natural resources are not carefully restored and managed, they may be lost forever. River restoration projects are commonly used where waterways have been damaged by human impact. Current studies are focused on determining the natural variability of river systems and restoring natural processes to pre-settlement conditions. In order to reach this goal of natural river restoration, several criteria must be met: (1) understanding of river complexities and geomorphic process, (2) development of theoretical similarities between river systems,(3) formulation of new criteria and standards for monitoring techniques, (4) practical application of scientific modeling, and (5) development of effective models tempered by economic and social realities. With these methodologies, current river systems may be restored and future damage may be entirely avoided. This paper examines the river restoration process, with examples of work in the Willamette Basin. Figure 1. (Wohl, 2006) Upstream view of Vindal River, northern Sweden, 2002 Stream was modified from two channels into single channelized flow Secondary flow blocked by rock dike at secondary head Figure 3. (ODFW, 2004) Beginning flow through the coffer dam constructed behind Marmot dam on the Sandy river. This project began in 1999 and final dam removal was completed in Coffer dams are composed of fill material normally found in the river system and are easily eroded through normal fluvial processes. Scope and intent of the dam removal is to recreate an uninterrupted fluvial system on the Sandy river, which has been influenced by humans since 1912 when Marmot dam was constructed. Figure 6. (PGE, 2007) Figure 3(Left) is an overlay of Spring Chinook runs in western Oregon fluvial systems and which part of the river is vital for each stage of a salmons life cycle Figure 4(Below) is a picture of a fish ladder implemented on the adjacent portions of a manmade river impediment, to assist salmonids in their upstream migration Figure 5(Upper Right) depicts where river barriers are on all fluvial systems throughout Oregon Figure 2. (Wohl, 2006)