In Norfolk, Virginia, some residents are raising their houses in order to fight flooding and counteract sea-level rise. (Photo/Morgan Heim)
Chesapeake Bay residents can breathe a little sigh of relief. The magnitude of absolute sea-level rise, the volume and mass of sea water, happening along its coastlines is a mere fraction of the global average, according to a new study. That’s a break the highly populated coastline needs because the other half the study shows that the land around the Chesapeake is sinking, a lot.
New research led by John Boon with the Virginia Institute of Marine Science (VIMS) found that absolute sea-level along the Chesapeake Bay is rising on average 1.8mm per year, about 50 percent of the global rate. “The bad news,” said Boon in a press release, “is that local subsidence more than makes up for it.”
Development and land use practices, such as increased population and groundwater withdrawals, are putting the pressure on the Chesapeake, literally causing the land to sink. In fact, the land is subsiding so much that it leads to an overall picture of sea-level impacts that outstrips many other regions around the world, said the study.
On average, relative sea-level rise – the amount of water rise in relation to land – for the Chesapeake is between 2.91 and 5.8 millimeters per year. To put that in perspective, either of those values is higher than the highest rates recorded for many other places, according to the press release. And while, 5.8mm per year might not sound like much, this adds up to about a 2-foot rise over the course of 100 years.
A flooded neighborhood in Virginia Beach, Virginia, after a July 2010 rainstorm dumped a month's worth of water in a 2-hour perioed. (Photo/Morgan Heim)
This is especially important news for Bay communities already threatened by increased flooding hazards from hurricanes and Nor’easters, said the study. Boon encourages further monitoring and mapping of sea-level trends that could aid in the adjustment of emergency response plans.
The Nature Files 
January 1st, 2011 at 12:05 pm
What does this say about global warming. The sky is falling! The sky is falling!
Is it possible that the 1.8 mm rise in sea level along the Bay might in part be due to the 100’s of thousand tons of sediment running into the Bay annually?
January 1st, 2011 at 7:41 pm
Hi Ken,
Thanks for your comment, and you are at least in part correct. A significant amount of the sea-level rise happening along the Chesapeake Bay is due to the land collapsing. And that in itself is a problem that we need to address. But the 1.8mm cited is in reference to what’s called absolute sea-level rise, which is the increase in the amount of seawater only. Regardless of what one believes about climate change, this info at least gives us better insight on how to address this problem and take care of our environment. Here’s the link to the actual press release if you want to read in more detail what the scientists found. Thanks again, and Happy New Year!
January 6th, 2011 at 8:32 pm
When I lived in Norfolk, flooding around our office building got so bad sometimes that we’d have to park about a mile away from the building and they’d shuttle us in in big vans with water seeping through the door cracks at the bottom. Anything to keep from giving us the day off I guess…