Flood

 

A flood can be defined as a general and temporary condition of partial or complete inundation of normal dry land areas from (1) the overflow of inland or tidal waters (2) the unusual and rapid accumulation or runoff of surface waters from any source, or (3) mudflows or the sudden collapse of shoreline land.

 

Floods are the most prevelant hazard in the United States, as well as in the TJPDC. Floods are natural evenets for rivers and streams. Excess water from snow melt, rainfall, or storm surge accumulates and overflows onto the banks and adjacent floodplains. Floods can occur anytime of year, anytime of dayin any part of the country. The biggest risk from floods are injuries and deaths when people are swept away by flood currents and property damage from the inundation by sediment filled water.

 

Severity of floods are determined by rainfall intensity and duration. Topography and ground cover are contributing factors for floods. Water runoff is greater in areas with steep slopes and little or no vegetation cover.

 

Flood plains are determined by the probabilty that flooding will occur each year. 100-year flood plains indicate locations that have a 1% chance of partial or complete inundation by water yearly.

 

 

TJPDC 100-Year Flood Plain Map(Requires Adobe©Acrobat)

Useful Links:

FEMA
FEMA interactive map (links to demographic tables)
Flood Fact Sheet