Sustainable sediment management at US Army Corps of Engineers reservoirs

Abstract

The US Army Corps of Engineers (USACE) maintains and operates 419 reservoirs nationwide for diverse purposes. This infrastructure is essential to the nation’s continued economic progress and provides numerous benefits. Sedimentation in reservoirs causes the loss of storage capacity, leading to interference with operations, reduction of project benefits, and eventual rendering of project operation technically infeasible or uneconomical. All reservoirs trap sediment, and sustainable long-term operation can be achieved only if sedimentation is managed. With many of the USACE reservoirs now reaching 50 years of age, sedimentation is starting to encroach on the beneficial pools. Under the paradigm of sustainable use, it is important to identify and implement strategies to sustain reservoir operation in the long term, beyond the period contemplated in the original project design life. This report outlines the major types of sediment management strategies available for reservoirs. Because the rate of new reservoir construction by USACE is very low, this report focuses on remedial strategies at existing reservoirs and presents a general methodology for the preliminary analysis of such sites. This report examines four example USACE reservoirs with known sedimentation issues to highlight the types of problems encountered and the development of strategies that can lead to sustainable use.