A flood is defined as any high flow...overflow...or inundation of water that causes
or threatens damage. Flooding can occur with prolonged rainfall over several
days...intense rainfall over a short period of time...or when water from an existing
source moves too quickly (i.e. snowmelt...dam break...etc.). Brief descriptions of the
various types of flooding you may experience are found below. More information
about these flood hazards can be found on the NWS Flood
Flash flooding: Flash Flooding is a rapid and extreme
flow of high water into a normally dry area...or a rapid water level rise in a stream or
creek above a predetermined flood level...occurring in a short duration (i.e. intense rainfall...
dam failure...ice jam). In southern New England...urban flash flooding is a concern due
to the potential for heavy rains to collect rapidly in poor drainage areas or overwhelming
River Flooding occurs when rivers rise and overflow their banks...inundating
areas that are normally dry
Tropical Systems and Coastal Flooding: At any time of year...a
storm from over the ocean can bring heavy precipitation to the U.S. coasts. Whether such a
storm is tropical or not...prolonged periods of heavy precipitation can cause freshwater flooding
in coastal areas...as well as further inland as the storm moves on shore. In addition to the
freshwater flood threat...tropical storms and Nor'easters can bring the threat of storm surge
related coastal flooding.
Snowmelt: Flooding due to snowmelt most often occurs in the
spring when warming temperatures quickly melt the snow. The water runs off the still partially
frozen or already saturated ground into nearby streams and rivers...causing them to rapidly rise
and sometimes overflow their banks.
Ice and debris jams: A backup of water into surrounding areas
can occur when a river or stream is blocked by a build-up of ice or other debris.
Dam break and levee failure: A break or failure can occur with
little to no warning. Most often they are caused by water overtopping the structure...excessive seepage
through the surrounding ground...or a structural failure.
Understanding the different flood hazards and knowing the actions to take
before...during...and afterwards can help you protect your life...the lives of your loved
ones...and your property. Prepare now by visiting
Join us tomorrow for information on flood related services provided by the National Weather Service.