Forum Hears Sea Level Rise Flooding Warning from Army Corps
October 03, 2013
A U.S. Army Corps of Engineers scientist gave an audience of planners, engineers and conservationists at Old Dominion University on Wednesday a synopsis of a $1.8 million government study of flooding potential in Hampton Roads, and she warned that some of the findings are sobering.
Army Corps researchers focused on the Norfolk Naval Station and its military readiness in the study, which was completed earlier this year. The project included an exacting assessment of equipment and infrastructure and how these "assets" would hold up if flooding worsens this century because of climate change and sea level rise.
"The government is not blind to what is going on with climate change," said the forum speaker, Kelly Burks-Copes, who is with the Environmental Laboratory at the Army Engineer Research and Development Center in Vicksburg, Miss., and who was a lead researcher for the project. She noted that the "fortification or retreat" aspects of military planning for climate change could hold lessons for municipal planners, private businesses and others with a stake in flooding potential.
Burks-Copes was also to give a brief explanation of the study at a town hall meeting on the topic of "Federal, State and Local Perspectives to Adapting to Sea Level Rise and Flooding" Wednesday evening at the Advanced Technology Center in Virginia Beach.
Models relied upon by the 22 investigators who worked on the Army Corps' study suggest mounting operational difficulties at the Norfolk base even with modest sea level rise. The team identified a "tipping point" somewhere between 0.5 and 1 meter of local sea level rise at which the base could be expected to be crippled for a significant period of time by a major storm.
The researchers found their task to be daunting, Burks-Copes said, because of the complexity of their mission. It involved determining not only how much water would flow into the base under a variety of climate change and storm conditions, but also how that water would affect operations at the base dependent upon electrical and steam power, water and sewer systems and other infrastructure. A major focus of the study was a set of three piers at the station where aircraft carriers tie up.
Burks-Copes explained that the researchers looked at sea level rise scenarios of 0.5 meter, 1 meter, 1.5 meters and 2 meters over the current century. Scientific estimates of the ocean's rise by 2100 have generally been within these parameters.
The sea level rise factor is considered in the report to be a "threat multiplier," she said, and the models and simulations she shared bore this out. When computers crunched the numbers of 1-meter or more sea level rise together with the realities of a 50-year or 100-year storm impacting the naval station, the results were much more devastating than from the storms alone. Within the storm factors, of course, are the high tides that can enhance storm surges.
A worst-case scenario - a combination of a 2-meter rise in sea level and a Category 3 hurricane passing over Norfolk - would leave the base under 9 meters of water, she said. "Yes, this is unbelievable, and it will be very hard to deal with."
The researchers studied where the water would enter the base, where it would collect and how it might leave. They even took a comprehensive look at the aquifer under the base, finding that the combination of sea level rise and a storm surge could mostly fill the aquifer, making it likely that floodwaters would stay in place for an extended period because they cannot seep into the ground.
Burks-Copes noted that the study factors in neither the well-documented subsidence, or sinking, of land in Hampton Roads, nor recent studies such as one from ODU oceanographer Tal Ezer that shows the Norfolk region could be a hot spot for sea level rise in the coming decades. Ezer's study bases predictions of hyper increases in sea level on a slowing of the Gulf Stream.
In addition to the big picture over decades, the Army Corps researchers considered incremental sea level rise that the region might expect in the short term, combined with the effects of storms the region can expect to sustain every year, as well as every 10 years. While infrastructure/operation damage under these lesser conditions would not cripple the naval station, the heightened flooding would likely present new challenges, Burks-Copes said.
The naval station study is one of four sea-level-rise risk assessments for security operations that the federal government ordered in 2008. One of the others looks at conditions in San Diego and the other two focus on the Gulf of Mexico.
The forum Wednesday was part of a series that began last year under a project titled "Hampton Roads Sea Level Rise/Flooding Adaptation Forum." Larry Atkinson, the ODU oceanographer who is co-director of the university's Climate Change and Sea Level Rise Initiative (CCSLRI), is one of the leaders of the project, which is sponsored by the Virginia Sea Grant, an affiliate of the National Sea Grant, ODU and the Hampton Roads Planning District Commission (HRPDC). Troy Hartley, director of the Virginia Sea Grant, which is headquartered at the Virginia Institute of Marine Science, is also a project leader, as is Benjamin McFarlane, physical and environmental planner for the HRPDC.
ODU launched its CCSLRI in 2010 with President John R. Broderick's challenge to "identify the multifaceted impact climate change and rising sea levels will have on our region ... and pull together the university and region's foremost experts to find solutions to the anticipated effects on our economy, housing, ports and infrastructure." Elizabeth Smith, an oceanographer who has been affiliated with ODU's Center for Coastal Physical Oceanography, is coordinator of CCSLRI, and the co-director with Atkinson is senior oceanography faculty member Hans-Peter Plag.
Measurements from Sewells Point on the lower Chesapeake Bay since 1927 show that the sea level has been rising about 1.7 inches per decade, and climate scientists say it is likely the rate will increase in the decades to come. Seas are rising because the water is warming (and expanding), land ice is melting and, locally, the land is sinking. ODU's initiative has identified 60 faculty members at the university with expertise that can be put to use in formulating this response. Many of them come from fields such as oceanography, marine science, environmental health, botany and coastal engineering, in which ODU has a rich history of fundamental research related to climate change. But CCSLRI has also engaged faculty members in humanities, business and education.
The goal of CCSLRI is to establish ODU as a leader in coastal urban adaptation to sea level rise and climate change.