By Janet Krenn
Flooding along Virginia’s coasts is just a fact of life, especially during hurricanes and Nor’easters. To monitor to flooding conditions, emergency managers along coastal Virginia have been turning to TideWatch, a water level monitoring system produced by Virginia Institute of Marine Science (VIMS) researchers. Recently, the VIMS researchers behind TideWatch released and, with the help of Virginia Sea Grant, trained emergency managers in a new experimental flood-forecasting system called the Real-time Storm Tide Observation and Forecast System (Rstofs).
VIMS researchers John Brubaker, John Boon, and Dave Forrest introduced the Rstofs system to emergency planners in Poquoson, Mathews, Gloucester, York County, James City, Williamsburg, Norfolk, Langley Air force Base, and the Hampton Roads District Planning Commission, as well as VDOT. The research team hopes that the Rstofs system will help emergency managers forecast events ahead of time, instead of simply in real-time.
Bringing this cutting-edge tool to Virginia’s coastal communities is at the heart of Virginia Sea Grant’s mission, says Virginia Sea Grant Director Troy Hartley. “Virginia Sea Grant has always strived to provide the best, most up-to-date scientific evidence to the Commonwealth’s coastal communities,” says Hartley. “These monitoring and forecasting tools are not only examples of sharing data and facts, but using research to solve problems our coasts are facing today.”
Flooding is caused by a combination of many factors, including rainfall and the height of the current tide. If it’s a high tide, overall water levels will be higher than if it’s low tide. TideWatch uses real-time water level data from nine monitoring stations to assess the latest water levels and projects forward in time with the aid of National Weather Service computer-generated storm surge forecasts.
For Boon, VIMS emeritus professor, the strength of their systems comes from this combination of observed water level and computer-generated forecasts. “We’re not concentrating on a hypothetical 100 year storm,” Boon says. “We’re basing predictions on actual data recorded from a storm in progress.”
The value of such a flood prediction system isn’t only realized in coordinating evacuations, but in protecting personal property.
“Even if there’s no call to evacuate, emergency managers can look at our system and say, ‘Move your car’,” says Boon, reflecting on the much-publicized automobile damage that occurred during the most recent Nor’easter in November 2009. FEMA estimated the public cost of that storm, which hit in combination with Tropical Depression Ida, exceeded $11M, not including what was paid out by private insurance.
City of Poquoson Deputy Fire Chief Mike Bryant had used the tide monitoring TideWatch system in the past and credits TideWatch with mitigating some property damage in Poquoson, where TideWatch data enabled emergency managers to issue a flood warning through the Code Red notification system.
“There was a lot of property and personal property that was undamaged because we were able to get that notification out to people,” says Bryant.
“The Nor’easter really opened our eyes,” says Bryant, who became interested in Boon’s research and in tidal monitoring after he saw the multiple flooding events caused by that storm. According to Boon’s monitoring data, the Nor’easter produced water heights equal to Hurricane Isabel, but during the Nor’easter, the flooding lasted longer.
“Our goal is to make sure that people are informed and informed quickly,” Bryant says. And for that “the first line of defense is TideWatch.”
For more information about TideWatch, check out Virginia Marine Resource Bulletin article “Forecasting the Rising Tide.”
