SAVANNAH — The federal government has given its final approval to deepen the Savannah harbor to make room for supersized cargo ships — a project that Georgia has sought for 16 years and that is expected to cost $652 million.

The Army Corps of Engineers announced Saturday that Assistant Army Secretary Jo-Ellen Darcy has signed a Record of Decision for the deepening project. That's the final green light needed from the federal government to move toward construction.

The Port of Savannah and others along the East Coast are scrambling to deepen their harbors to accommodate giant ships expected to begin arriving through the Panama Canal after it completes a major expansion in 2014.

Georgia officials hope to have the Savannah River channel deepened from 42 feet to 47 feet in 2016.