Water Injection Dredging: A Cost-Effective Force of Nature

Water injection dredging (WID) is an innovative hydrodynamic dredging technique that is cost-effective, low-impact, and environmentally sound. The WID injects large volumes of water at low pressure into the sediment layer, and the resulting fluidized sediment is then carried horizontally along the waterway as a density current, keeping the sediment in the system and eliminating the need for a disposal site. This paper provides an overview of the WID theory of operation by describing the vessel, its components, density current dynamics, and site feasibility based on geotechnical characteristics of shoal material. Additionally, the paper summarizes the research performed on the dredging operation, density current dynamics, and the short-term fate of the dredged sediments during WID operations at Wilmington Harbor, NC, in January 2022. The findings are that the WID dredging method is operationally efficient and well-tailored to local hydrodynamics to maintain the harbor in an environmentally sustainable manner.