ABSTRACT
The winning idea of the 2022 Guardians of the Reservoir Challenge, the Continuous Sediment Transfer, has shown great potential as an effective way to restore or maintain the functionality of reservoirs capacity and restore ecological conditions in downstream aquatic systems. The competition was organized by the Bureau of Reclamation (BoR) and United States Army Corps of Engineering (USACE) and had three stages: submitting an idea, developing a concept, and demonstrating the technology in a field test. The winning idea, which was selected by a technical jury, was Continuous Sediment Transfer, a near-natural method for autonomous restoring and maintaining reservoir volume and restoring sediment conditions in the tailwater.
The team’s technology, the SediMover, was used to remobilize the sediment inside the reservoir and transfer it to the tailwater. Its modularity allows for adaptation to almost every situation, including difficult situations such as flood events and dry falls or quantitative limitations in sediment transfer. The team successfully demonstrated the process in a field test, which was presented in a demonstration video, a presentation, and a written essay. The technology is expected to undercut the cost of applying conventional dredging methods for reservoirs, thus saving reservoir operators money. Nevertheless, the new technology can be combined with conventional dredging technology and other equipment. After the pilot application in the competition, the team already has three larger commercial projects in preparation in Germany.
In addition to the practical need for application, the team aims for a broad and scalable application of the developed technologies. The judicious application of autonomous dredging will not only ensure cost-effective remediation of reservoirs and ensure their future operation but will also restore sediment continuity in rivers in a naturalistic manner. The benefits are not limited to the immediate downstream sections of the river but extend far downstream to river deltas and coastal regions, preventing further erosion damage. In this way, ecological benefits are achieved at no additional cost.
Moreover, the team is participating in developing guidelines for sediment management in reservoirs and researching the combination of sediment methane gas harvesting with the continuous sediment transfer, using different autonomous vessel types. The team is also working to adapt the technology to harvest methane generated inside the sediment to combat greenhouse gas emissions. Furthermore, a smaller version of the SediMover, the MiniMover, has been developed for use in tributaries, limited spaces of reservoirs or shoreline areas.
The Continuous Sediment Transfer process conducted with autonomous vessels shows great potential as it combines ecological benefits with economic benefits to combat a global problem. Reservoir operators and the government will have to invest significant sums in the coming years to ensure water supply in several regions of the USA and in Europe. Therefore, the automation achieved by the technology will ensure that it is able to undercut the cost of applying conventional dredging methods for reservoirs, thus saving reservoir operators money. The team’s technology is expected to have good prospects as it offers both ecological and economic benefits.
