Friday, Oct. 26, 2007
by Kevin J. Shay | Staff Writer
In 1900, a major hurricane hit the Texas coastal city of Galveston, resulting in more than 8,000 deaths — still the greatest toll for a natural disaster in U.S. history.
Galveston leaders responded by raising some homes and businesses and building a 3-mile, 17-foot-high seawall along the beach near the downtown area that was later extended to 10 miles. That action ‘‘dramatically lowered the loss of life and destruction” during ensuing hurricanes, according to the Galveston and Texas History Center.
As Maryland grapples with being one of the states most vulnerable to rising sea levels in the coming decades because of climate change, some point to examples such as Galveston.
‘‘Sure, seawalls should be studied,” said Antonio J. Busalacchi, a professor in the University of Maryland’s Department of Atmospheric and Oceanic Science and director of the Earth System Science Interdisciplinary Center. ‘‘But it’s just one of many possible courses of action in response to climate change.”
Constructing a seawall and bulkhead protection for Maryland’s 31 miles of Atlantic Ocean coastline would cost anywhere from $37 million to $1 billion, according to a report by the University of Maryland’s Center for Integrative Environmental Research.
Building levees to protect against as much as a 3-foot predicted rise in sea level by 2100 along Maryland’s Atlantic shore will cost from $37 million to $200 million, the report says.
Those costs and the aesthetics of seawalls don’t make that the ideal option for the state, said Douglas M. Duncan, vice president for administrative affairs at the University of Maryland, College Park, and former Montgomery County executive.
‘‘It’s not feasible,” Duncan said. ‘‘We need a national center for climate change that can come up with a comprehensive program of action.”
Busalacchi echoed the need for a national information clearinghouse, but he noted that leaders in cities such as New York are studying seawalls.
Slowing down emissions of carbon dioxide and other greenhouse gases faces ‘‘considerable political and economic challenges,” according to a report from NASA’s Goddard Institute for Space Studies in New York.
‘‘Alternatively, dikes and seawalls can be built around the airport runways and vulnerable low areas, peripheral highways can be elevated and beaches can be periodically replenished with sand,” the NASA report says. ‘‘Legislation could require new buildings to lie inland beyond a designated amount of sea level rise or erosion extent.”
A Maryland commission reviewing climate change issues is slated to release preliminary recommendations next month. Maryland joined several other states this year in a commitment to reduce greenhouse gas emissions.
Some studies have found that seawalls aren’t really a long-term solution because waves eventually damage the wall and erode the sand beneath it. Galveston Mayor Lyda Ann Thomas has said in published reports that if Hurricane Rita had hit the city head-on in 2005, the waves would have easily surged over the seawall and swamped the island.
Other studies, however, credit a stone seawall along Puducherry — a territory in India — with saving thousands of lives and preventing millions of dollars in property damage during the 2004 tsunami. That wall rises to as high as 27 feet.
Several villages in Alaska are building seawalls or strengthening existing walls to guard against erosion from global warming. Four villages — Kivalina, Koyukuk, Newtok and Shishmaref — are in ‘‘imminent danger,” and leaders there want the villages to be relocated to other areas, according to a U.S. Government Accountability Office report.
The last tropical storm to hit Maryland was Isabel in 2003. That storm caused water to rise as much as 8 feet higher than normal and flood numerous homes and businesses in the state, leaving parts of downtown Annapolis inundated.
