Title: The Science of Dam Removal
Abstract: In this talk I will provide an overview of recent trends in dam removal in the USA and western Europe.  I 
will start by describing some of the basic characteristics of dams (height, age, purpose, etc.), then review key 
legislative actions in the USA and western Europe that are driving upward trends in dam removal.  In most cases, the 
impetus for dam removal is related to the cost of retro-fitting an ‘old’ dam to comply with modern environmental 
policies versus the cost of taking the dam out.  Far more dams have been removed in the USA than anywhere else.  
Experience from these dam-removal projects indicates that the downstream impacts associated with entrainment and 
transport of sediment deposited behind a dam are short-lived, primarily because the majority of the sediment 
mobilized is fine-grained (silt and sand).  Given the age- and size-distribution of dams, most future projects will 
focus on dams and barriers that are greater than 50 yr in age and less than ~15 m in height.