Navigating Dam Removal Costs

The objective of this effort is to provide information relevant to developing planning level costs for dam removals. An interdisciplinary team with experience in dam removal developed information useful to planning level cost estimating. The method utilizes available data and professional knowledge of dam removal projects to identify ranges of potential dam removal costs, physical characteristics associated with the dam removal cost groupings, and what factors led to lower versus higher cost dam removals. Several hundred dam removal projects were acquired to document the total cost of dam removal projects, with some categorical information as to whether potential cost drivers were present. Additional more detailed data was acquired on a limited number of projects through interviews with technical leads involved in the dam removal and construction cost estimates. The study found dam size was not a good predictor of the order of magnitude of costs, but rather other factors such as replacement infrastructure, restoration needed, access, litigation, and stakeholder concerns drove costs into higher categories. This list is not intended to be exhaustive, but to provide guidance in conceptual planning when considering dam removal as an alternative. Resulting tools will be presented including a flow chart of whether a dam removal is likely to encounter cost drivers, and what engineering data is needed to develop planning level costs relevant to developing a cost estimate. Additionally, new data sets hosted by USGS and Oregon State will be presented that will be publicly available and downloadable. Finally, we will recommend a protocol for documenting dam removal cost data to help inform future planning level cost estimates.