A Benefit/Cost Index for Prioritizing Small Dam Removals

摘要

There are large numbers of aging dams located throughout the United States. Manyof these dams are small and no longer serve their intended purpose and will continue todeteriorate until such time as they will ultimately fail. For some of these dams theconsequences of dam failure may involve substantial downstream injury and propertydamage as well as catastrophic and long-lasting environmental effects. Many dams arealready detrimental to fish migration and may have significantly altered the downstreamsediment budget causing changes in habitat characteristics. As a result, many stateagencies and environmental groups are considering dam removal opportunities. However, itis difficult to rapidly, accurately and cost effectively prioritize a large inventory of candidatedams based on the various and divers factors influencing the significance of each removalproject. This paper presents a framework for the use of a benefit/cost index to prioritize theremoval of small dams over a large inventory. This framework is not meant to dictateprotocol, but rather to stimulate discussion and awareness of the many trade-offs involved inthe decision to remove a dam. The adoption of a prioritization indexing methodology isrequired to use limited resource dollars efficiently.