Environmental Effects of Cyclical Reservoir Drawdown on Archaeological Resources: A Preliminary Case Study from Fall Creek Reservoir, Lane County, Oregon

Summary

This is an abstract from the "SAA 2021: General Sessions" session, at the 86th annual meeting of the Society for American Archaeology.

The Willamette Valley Project of the United States Army Corps of Engineers (USACE) manages 13 reservoirs in northwestern Oregon. The USACE’s flood control mission requires annual water level drawdowns that expose the reservoir bed to cycles of lacustrine deposition, wave-action, and alluvial and colluvial erosion. Previous assessments of the impacts of drawdown cycles on archaeological sites have categorized sites as above, within, and below the drawdown zone thereby conflating sites dominated by annual erosional and depositional processes. In this poster, we apply a new sediment transport model (Keith and Stratton 2019) to describe the drawdown impacts to cultural sites in Fall Creek Reservoir with greater precision than previous models permitted. Five zones are identified: (1) Uplands, (2) Littoral Floor, (3) Reservoir Slope, (4) Pelagic Floor, and (5) Deep Pelagic floor. By comparing surface assemblages, artifact distributions, and stratigraphy, we characterize the erosional/depositional effects, visibility, and stability of cultural sites within each zone. Implications for site management and survey methodology are discussed.

This Resource is Part of the Following Collections

• Society for American Archaeology 86th Annual Meeting, Online (2021)   •
• SAA 2021: General Sessions

Keywords

Record Identifiers

Abstract Id(s): 32502