Marine Corps officials are considering the future of some East Coast installations threatened by flooding and other climate change effects, including its historic recruit training depot in South Carolina.

A Department of Defense-funded military installation resilience review of two military installations in Beaufort County, South Carolina and surrounding South Carolina communities found that Marine Corps Recruit Depot Parris Island and Marine Corps Air Station Beaufort is particularly vulnerable to natural hazards made worse by climate change.

The low-lying depot, which trains about 17,000 Marine recruits every year, is threatened by increasingly frequent hurricanes, storm surges, flooding, coastal erosion, marsh loss and extreme heat.

By some estimates, up to three-quarters of MCRD Parris Island could be underwater at high tide by 2099.

Defense officials said the threat has led Marine Corps officials to consider alternate locations for the installations.

“I’m aware that there are conversations in the Marine Corps about the possibility of moving bases right now,” Meredith Berger, the assistant secretary of the Navy for environment, installations and energy told Military.com.

Marine Corps officials said one of the options they are considering is the construction of a new consolidated base that would perform the functions of the threatened installations.

Parris Island was first used by the U.S. Navy in 1861 during the Civil War and was made a permanent military installation in 1891. The base became the nation’s primary Marine Corps Recruit Depot in 1915.