Rising sea levels pose threat to Fort McHenry, inspector general reports

Rising sea levels pose threat to Fort McHenry, inspector general reports
Fort McHenry in Baltimore and dozens of other national parks are threatened by rising sea levels, the Department of Interior's inspector general reports, presenting officials with "a major management and performance challenge" over the next century. (Kenneth K. Lam / Baltimore Sun)

Dozens of national parks — including Fort McHenry in Baltimore — are threatened by rising sea levels, the Department of Interior's inspector general reports, presenting officials with "a major management and performance challenge" over the next century.

As water levels rise at an increasing pace, the inspector general reported this month, "more than one-third of assets in the Northeast are in the high-exposure category, from the Statue of Liberty in New York to the landmark structures at Boston National Historic Park and Fort McHenry in Baltimore."


The fort, where 1,000 U.S. soldiers withstood a British bombardment in 1814, inspiring Francis Scott Key to write the poem that became "The Star Spangled Banner," has long coexisted uneasily with the Patapsco River. It is separated from the river by stone sea walls dating to the 19th century.

"The story of the fort is always linked to the water, for good or bad," said Vincent Vaise, chief of interpretation at the star-shaped structure, which was established as a national park in 1925.

"The British attack was one day. Mother Nature attacks every day of the week," Vaise said. "The British were easy compared to Mother Nature."

The fort's history includes several skirmishes with rising water levels.

Trash washed ashore by Tropical Storm Isabel in 2003 stretched for a mile. The debris included a 1,000-pound channel marker tossed up on the grass.

Torn-up dock boards, thousands of plastic bottles and assorted flotsam tarnished part of the Fort McHenry Marsh, created 30 years ago to compensate for wetlands destroyed by the construction of the Fort McHenry Tunnel.

During a tour of the fort last week, Vaise pointed to bottles, wrappers and other garbage washed up by recent storms and deposited in sea grass. Low-lying sections of the fort's property are perhaps five or six feet from the water's edge.

"Just before the 1814 Battle of Baltimore, the kitchens were filled in because of rising water levels," Vaise said. "They were below ground level. We have records of people fighting mold, slime, that kind of stuff dating back to the Civil War."

The inspector general summarized the top challenges facing the Interior Department. Climate change was joined on the list by disaster response on federal lands and responsibility to American Indians, among other concerns.

The inspector general cited research released in May by National Park Service and Western Carolina University scientists predicting a 1-meter sea level rise in the next 100 to 150 years. A meter is a little more than 3 feet.

"A 1-meter rise would trigger cascading effects, including increased storm surge, coastal erosion, wetland and coastal plain flooding, salinization of aquifers and soils, and a loss of habitats for fish, birds, and other wildlife and plants," the inspector general reported.

Fort McHenry was among 40 National Park Service sites that the scientists said could be threatened. Others included the George Washington Birthplace National Monument in Virginia, Assateague Island National Seashore off Maryland's Eastern Shore, and the Statue of Liberty.

While most of Fort McHenry has "limited exposure," the inspector general reported, "the assets on the very exterior of the monument [such as the seawalls] were considered high exposure."

The seawalls aren't just barriers, Vaise said — they're part of the fort and its story. He was pleased the inspector general called attention to water level concerns because "when you look at history, it's not about the next five or ten years, it's about the next 100 years."


Fort McHenry is far from the only historic Maryland property at risk from rising waters as the climate changes.

"With Fort McHenry, we know what we could potentially lose," said Nicholas Redding, executive director of Preservation Maryland. "The problem with a lot of historic resources is they have not been surveyed. There's not enough survey money out there."

Downtown Annapolis boasts the largest concentration of 18th-century Georgian architecture in the nation, according to the Historic Annapolis Foundation. Many of the historic structures are within the city's 100-year flood plain, which was last inundated in 2003, when Isabel swept up the bay.

The Washington-based Union of Concerned Scientists reported last year that Annapolis' historic district, the Naval Academy and the new Harriet Tubman Underground Railroad National Monument in low-lying Dorchester County are among dozens of historic sites nationwide at risk from rising sea level, flooding and worsening wildfires.

Fort McHenry, a national monument and historic shrine, is visited by an average of 650,000 to 700,000 people a year. Celebrations of the bicentennial of the victory at Fort McHenry in September 2014 featured ships, fireworks and cannon fire, and drew nearly 1.5 million people.

According to the Maryland Historical Trust, the most recent estimates for sea-level rise in Maryland are about 2 feet over 50 years, and as much as 3.7 feet by 2100.

"Water is central to the story of Maryland," Redding said. "As a result, a lot of our most historic structures are built very close to the water."