The Corps’ navigation responsibilities are planning and constructing navigation channels, locks and dams, and dredging to maintain channel depths in U.S. harbors and inland waterways. In partnership with local port authorities, Corps personnel oversee dredging and construction projects at dozens of ports and harbors in the Northeast. Five of the nation’s top ports are located in North Atlantic Division — Boston and Portland harbors, the Port of New York and New Jersey, the Port of Philadelphia, Baltimore Harbor, and Norfolk Harbor (Hampton Roads). Roughly 35 percent of U.S. waterborne tonnage is handled through ports in the division’s area.