Reservoir Sedimentation and Storage Capacity in the United States: Management Needs for the 21st Century

The United States federal government invested significant resources to build dams in the mid-twentieth century to increase water storage capacity nationwide; while only 5% of the dams in the United States are federally owned, they account for 61% of the total national storage capacity. Society is increasingly dependent on reservoir storage capacity due to increased water demand, increased population growth on floodplains protected by flood control dams, or increased demand on hydropower as a critical part of the electricity grid. Simultaneously, reservoir sedimentation diminishes storage capacity. Thus, there is a persistent chronic loss of the very resource upon which many aspects of modern society depend. Not measuring, assessing, and managing this resource undervalues it, and also perpetuates ignorance of threats to existing beneficiaries as well as obscuring opportunities for additional benefits. In order to most efficiently use the nation’s increasingly scarce reservoir storage capacity, the authors propose three modest actions for the hydraulic engineering community in the Journal of Hydraulic Engineering: expand nationwide reservoir sedementation surveys, supplement RESSED with initial planned sedimentation rates, and share responsibility for building reservoir sedimentation knowledge.