DOI: 10.7267/h415pj58r
title: Database of detailed costs of dam removals
title: Dam removal costs

description: Dam removal is an important management tool for addressing aging infrastructure, public and structural safety, restoration of river connectivity for migratory organisms and recreation,  and habitat quality. However, planning for dam removals is constrained by the difficulty of cost estimation. To our knowledge, published data on dam removal plans, total costs, and the cost drivers does not currently exist. The lack of information limits the ability of practitioners to consider dam removal as an alternative to addressing infrastructure issues. To address this deficiency and to identify which factors drive the costs of dam removals, we compiled a detailed cost database as a collection of 15 case studies with detailed removal costs and features of the dams. Detailed costs were extracted from bid abstracts and/or schedule of values, and dam features (e.g. stored sediment volume, composition, and contamination, dam removal strategy, streamlining of permitting, mitigation measures) were based on interviews with project managers. The data set illustrates how and why dam size (e.g., height) only roughly predicts cost of removal. The data indicate that sediment volume and management strategy better predicted removal cost than dam height. Other cost drivers appear to be restoration activities (e.g. revegetation, fish passage, stabilization), construction approaches (e.g. dewatering, construction of channel features) and mitigation measures (e.g. water supply, pumping plants). Finally, unique features of individual projects contributed to higher costs, including litigation, stakeholder engagement, or mitigation projects. The databases will be publicly available and are being used in the development of order-of-magnitude cost estimation tools.
description: Database development: We first identified the cost categories (construction, non-contract, mitigation, monitoring, litigation, stakeholder support) and project features based on our collective experience with dam removal and information discussion with consultants. The database was developed in Excel based on these cost categories and features. 

Recruiting consultants: We compiled a list of personal contacts for consultants working on dam removals. Everyone on this list was contacted to request participation and recommendation for additional study recruits. 

Data assimilation: Consultants shared bid abstracts and schedules of values with the project team. Those data were compiled into the cost categories by the consultant with some guidance from the project team, though the classification of many individual costs into these categories was subject to some individual discretion. Project features included many details about the decommissioning and restoration plan, including things like how sediment was managed, what mitigation infrastructure (e.g. pumping plant, hatchery, levee enhancement/maintenance, etc.) was required, and the site restoration plans. These features were primarily determined by phone or web-based discussions with consultants. 

Data were collected by OSU researchers (Tullos, Bernandino, and Brainerd) as described above and were compiled in a shared Excel workbook.  Project features were identified as cost drivers based on simple linear regression.