Coastal engineering alternatives can have impacts on sediment movement and shorelines, particularly in the region around inlets and navigation channels. In response, the Corps has developed a systems approach to sediment management.
Regional sediment management (RSM) refers to the use of littoral, estuarine, and riverine sediment resources in an environmentally beneficial and economical manner. RSM strives to maintain or enhance the natural exchange of sediment within the boundaries of the physical system. A region may include a variety of geologic features, such as uplands, beaches, inlets, rivers, estuaries, and bays, and is defined by the sediment transport paths within this physical system.
Implementation of RSM recognizes that the physical system and embedded ecosystems are modified and may respond to natural forcing and engineering activities beyond the formal dimensions and time frames of individual projects.
The Corps mission to ensure the navigability of U.S. waterways involves removing, transporting, and placing sediment. Some of this material can be used to achieve goals in other mission areas, such as environmental restoration and shore protection.
RSM can be implemented by mitigating the effects of structures, such as jetties, by bypassing sediment around transport-blocking structures. This action maintains sand-filled beaches downdrift of inlets and structures, thereby protecting areas upland of the sandy beaches from waves and flooding. RSM can also be enacted by using dredged material to create marsh substrate for habitats. This benefits the environmental restoration mission and can provide shore protection as well.
These types of actions-a systems-based approach-can combine engineering efforts, reduce costs, and involve multiple stakeholders in coastal projects.