The U.S. government acquired Water Island in 1944 for a coastal defense installation. Water Island is the smallest of the U.S. Virgin Islands and is approximately 1,800 feet from St. Thomas, south of Charlotte Amalie. The Army constructed barracks, gun emplacements, watch towers, underground bunkers, and various other structures, and the installation became known as Fort Segarra. The Army constructed Battery 314 at the top of a hill in the southern portion of the island, but the guns were not installed, and the emplacement was never operational. The Army did install guns at two places associated with the 818th Anti-Motor Torpedo Boat Battery (Druif Point and Providence Point). There were two 37 millimeter guns at both locations and two 90 millimeter guns at Druif Point. With World War II winding down, the Army deactivated the 818th Battery in 1945 and deactivated Fort Segarra in 1946. The Army used Fort Segarra between 1948 and 1950 for tests associated with the Tropical Test Program. Most of that land comprising this Formerly Used Defense Site is now privately owned.
The Corps has conducted a number of investigations of the former Fort Segarra over the years, and a removal action to search for and remove any munitions-related items was completed in 2009. In addition to the removal action, the Corps installed signs at the public ferry and deep water docks to make sure the public is aware of the military's use of the island. The Corps conducted a review in 2012 to see if the remedial action implemented in 2009 is still effective in protecting people from potential risks associated with the military's use of the island. That led to the Corps replacing the two signs.
While no munitions or munitions debris have been identified in more than 20 years, to ensure public safety, the Corps is conducting a Remedial Investigation/Feasibility Study to determine if anything from the military's training remains in the area and to identify appropriate future actions.