Flood sensors to aid county in evacuation planning

Chapel Hill, NC, September 5, 2007 – A hybrid network of flood and weather sensors to be installed over the next two months will give Brunswick County emergency managers advance warning about how fast water is rising along critical flood-prone roads in the county.

The system, a prototype developed by the Renaissance Computing Institute (RENCI), will make use of a network of water level sensors and new weather stations to give emergency personnel in this coastal county crucial information about advancing storms and flood waters. The system could reduce the impacts of floods by providing earlier and more detailed information about critical evacuation routes across the county. The data collected by the sensors and weather stations will give people more time to evacuate and allow emergency workers to see the progress of floodwaters in order to re-route evacuations and rescue efforts.

“Each sensor location is a combination of weather and hydrology sensors that give us a real-time depiction of rising waters,” said Ken Galluppi, a senior researcher and meteorologist who heads RENCI’s disaster research efforts. “They will be placed at flood-prone sites along roadways and will transmit data back to a central computer at RENCI for processing and dissemination to the county’s Emergency Operations Center and the National Weather Service in Wilmington. The result will be a better ability to forecast road closures and more up-to-date information on changing conditions in order to conduct evacuations or rescues.”

Brunswick County, in the southeastern corner of North Carolina, is extremely flat and prone to flooding, especially when tropical storms strike, bringing many inches of rain well before the  storm reaches land. In addition, the county has only a few routes for evacuating coastal residents when hurricanes threaten the area. Main evacuation routes often flood, and currently, the only way to monitor the roadways is to send out state troopers or emergency workers to monitor floodwaters and report back.

“RENCI’s flood sensor systems will help us to prepare better for flood disasters. With our increasing population, there are fewer evacuation routes, which presents a challenge  for evacuating people, especially those with medical or other special needs,” said Randy Thompson, emergency services director for Brunswick County. “Many of the low-lying roads become impassible and there is insufficient monitoring information available on the rainfall or water movement. A lot of our flood monitoring has depended on someone to observe the water level and report their findings by radio.”

Fourteen points along evacuation routes in Brunswick County have been identified as flood-prone areas and will be equipped with sensors. Eight of those sites were identified as high-priority areas. Each site will be equipped with one or more flood sensors calibrated to the road surface and a base station installed on higher ground containing a battery, microcomputer and communications equipment.
In addition, RENCI installed seven weather stations around the county for the hurricane season, which will gather atmospheric data from areas not covered by existing stations. These stations will compliment the flood sensors by providing information on wind speed, precipitation, barometric pressure and other conditions. The sensors will relay water level data to county officials via the base stations and will be able to operate even when they are submerged. The flood sensor sites are:

  • U.S. Route 17, Beaver Dam (0.25 miles south of MM37, Route 17)
  • NC 133 near Funston Road
  • NC 133, Long Beach Road (near the Chamber of Commerce building)
  • NC 87, at the BSL Bridge
  • U.S. 17, MM17, (Ford Dealership)
  • U.S. 17, Omni Storage (near Shallotte)
  • NC 211Lockwood’s Folly Bridge on
  • Ocean Isle Beach Road in Shallotte

Highway 17 is the main artery crossing the county from South Carolina to the main inland evacuation routes of U.S. 74 and 76, which crosses into New Hanover County and connects to Interstate 40. The main evacuation routes from the beaches to U.S. 17 include state highways 133, 211, 87 and several local roads, all of which are prone to flooding from heavy rains.

After several months of testing, data will be disseminated to the National Weather Service and through RENCI’s NC-FIRST program, a Web-based tool designed to help emergency managers decipher weather data, understand weather threats and choose actions that minimize the threats to lives and property caused by extreme weather. RENCI plans to leave the flood sensor network system in Brunswick County for county officials to maintain.