Coastal and inland waterways are critical to commerce, defense, and recreation in the United States. The Corps has been charged with maintaining navigable waterways since the early 19th century.
The requirements for access and protection in harbors and ports often lead to dredged channels and engineered structures, such as jetties and breakwaters. These project features can impact dynamic coastal processes and lead to a range of coastal engineering concerns. Ports and harbors must be located so that vessels can penetrate coastal waters and interface with land. Ideally, vessels have a relatively short travel distance between harbor/port areas and open water. Vessels must have sufficient water depth and protection to safely enter and exit the harbor/port area. Thus, a well-maintained, clearly identified channel through any shallow areas is needed.
The terms deep-draft and shallow-draft are often used to distinguish between major commercial port projects and recreational or other small boat harbor projects:
- Deep-draft means a channel depth greater than 4.6 m (15 ft)
- Shallow-draft means a channel depth less than 4.6 m (15 ft)
With pressure to serve larger ships, many U.S. ports are faced with costly infrastructure upgrades. Deeper and wider channels, turning basins, and berthing areas are needed. Disposal of large quantities of dredged material, which is often contaminated after many years of harbor operations, can be a major and expensive problem. Demand for small-craft berthing space is also increasing, mainly to serve recreational boaters. Accordingly, there is a continuing economic incentive for expansion of existing small-craft harbors and development of new harbors.