Hurricane Awareness: Inland Flooding
July 19, 2012
When it comes to hurricanes, wind speeds do not tell the whole story. Hurricanes produce storm surges, tornadoes, and often the most deadly of all, inland freshwater flooding.
While storm surge is always a potential threat with land-falling hurricanes, many more people have died from inland freshwater flooding. Inland flooding can be a major threat to communities hundreds of miles from the coast as heavy rain falls from these huge tropical air masses. last year, the flooding caused by Tropical Storms Irene and Lee caused considerable damage and 36 deaths in the mid-Atlantic and New England States.
In 1972, Hurricane Agnes produced floods in the Northeast United States which contributed to 122 deaths and $6.4 billion in damages. And in 1955, long after the winds from Hurricane Diane had subsided, the storm brought inland flooding to Pennsylvania, New York, and New England contributing to nearly 200 deaths and $4.2 billion in damages.
Freshwater floods accounted for more than half of U.S. tropical cyclone deaths from 1975-2004 years and more than 75% of the children killed by tropical cyclones. Flooding is also the reason that 63% of U.S. tropical cyclone deaths during that period occurred in inland counties. At least 23% of U.S. tropical cyclone deaths are people who were attempting to drive through flooded roadways. "Turn around, don't drown".
Here in New England, tropical systems can combine with mid- latitude weather systems (extra-tropical) to produce very heavy rains and flooding, even when the hurricane or tropical storm remains well offshore. In fact in 1996, a coastal storm that was fed tropical moisture from the circulation around Hurricane Lili (well offshore) produced from 4 to 19 inches of rain across southern and central New Hampshire and southwestern Maine and was responsible for one drowning death.
Here are some tips to protect you and your home from flooding.
DID YOU KNOWHistorically, storm surge had been the leading cause of death during hurricanes. However, improvements in forecasting and communication has allowed potential victims to evacuate from surge prone areas. These improvements have greatly reduced the number of storm surge deaths in the United States. As seen in the table below, freshwater flooding is by far the leading cause of death from tropical cyclones.
- Develop a flood emergency action plan.
- Determine whether you live in a flood-prone area.
- If flooding is possible, move valuable items from the basements or first floor to higher floors in your home. Have a checklist of these items in your emergency action plan.
- Keep abreast of road conditions through the news media, local officials and MaineDOT's 511 travel information service. Move to a safe area before access is cut off by flood water.
- If advised to evacuate, do so immediately.
- Do not attempt to drive through a flooded roadway. As little as six inches of rapidly moving water can cause some vehicles to be pushed off the roadway.
Also, If you live in a flood-prone area, consider purchasing flood insurance. Flood damage is not usually covered by homeowners insurance policies. Do not make assumptions; check your policy.
The National Flood Insurance Program is a pre-disaster flood mitigation and insurance protection program. The National Flood Insurance Program makes federally-backed flood insurance available to residents and business owners in certain communities. For more information, visit FloodSmart.gov.
Question of the Day:
The National Weather Service has declared the week of July 16th through the 20th to be Hurricane Awareness Week in New England. (This information was prepared by the National Weather Service, Gray, Maine.
For additional information about hurricanes and hurricane safety, visit the National Hurricane Center's web site