Impacts to Historic Properties in Drawdown Zones at Corps of Engineers Reservoirs

Abstract : The U.S.Army Corps of Engineers is required by Federal law and by its own regulations to protect 'historic properties' (archaeological sites eligible for the National Register of Historic Places) from adverse impacts or to mitigate ad verse effects through data recovery, site stabilization, etc. Sites located within the drawdown zones at Corps reservoirs are being adversely affected by fluctuating water levels caused by normal reservoir operation. Seasonal drawdowns cause a variety of erosion-related impacts and expose sites to human vandalism. Strategies must be devised to prevent or mitigate adverse impacts to these significant cultural resources. This report deals with the nature and occurrence of impacts to historic properties along the shorelines and in the drawdown zones of Corps of Engineers reservoirs. It presents the survey questionnaire responses obtained from all Corps Districts and describes the management practices observed in field visits to nine Corps reservoirs. This report describes the scope of the drawdown problem' and the variety of adverse impacts from erosion, biochemical effects, and vandalism. An overview of previous research to counteract these impacts is also presented.