Reservoir sedimentation and what to do about it.

In June 2019, Reservoir Sediment Management: Building a Legacy of Sustainable Water Storage Reservoirs was released by the National Reservoir Sedimentation and Sustainability Team (NRSST), a consortium of engineers and scientists from federal agencies, consulting firms and universities, including UC-Berkeley’s RiverLab, studying the impacts of sediment on the nation’s water supply.

 

This paper outlines the origins and legacy of reservoir sedimentation, where sediment being transported by a river begins collecting behind a dam. While sediment transport is of great benefit to riverine ecologies, the trapping of sediment means decreased water storage capacity in dams, greater flood risk, and reduction in hydropower functions.

Additionally, the paper proposes the following management strategies for mitigating further sedimentation and dealing with existing sediment:

  • Reduce sediment yield entering the reservoir by trapping more upstream;
  • Move sediments away or through reservoirs;
  • Flush or dredge existing sediment deposits;
  • Adapt to and plan for reduced storage volume in the future. (Randle, 2019)

 

Read the full paper by clicking here

 

Tim Randle of the NRSST and Manager of the Sedimentation and River Hydraulics Group at the Bureau of Reclamation was featured in H2O Radio’s recent story “Damned from the Start” discussing the reservoir sedimentation as it applies to the flooding of the Niobara River behind the Gavins Point Dam in Nebraska.

 

Listen to the full story here