Laserfiche WebLink
atmospheric pressure. Storm surge is extremely dangerous, <br />because it is capable of flooding large coastal areas. <br />Inland Flooding — Occurs when moderate precipitation <br />accumulates over several days, intense precipitation falls over <br />a short period, or a river overflows because of an ice or debris <br />jam, or dam or levee failure. <br />Flash Flood — Caused by heavy or excessive rainfall in a short <br />period of time, generally less than six hours. Flash floods are <br />usually characterized by raging torrents after heavy rains that <br />rip through river beds, urban streets, or mountain canyons <br />sweeping everything before them. <br />In Indian River County, several variations of flood hazards <br />occur due to the different effects of severe thunderstorms, <br />hurricanes, seasonal rains, and other weather-related <br />conditions. For the majority of the County, the primary causes <br />of flooding are hurricanes or tropical storms. However, the <br />County's low-lying topography, combined with its subtropical <br />climate, make it vulnerable to riverine as well as storm - <br />associated flooding. <br />Flooding in Indian River County results from one or a <br />combination of both of the following meteorological events: <br />• Tidal surge associated with northeasters, hurricanes, <br />and tropical storms; and <br />• Overflow from streams and swamps associated with <br />rain runoff. <br />When intense rainfall events occur, streams and drainage <br />ditches tend to reach peak flood flow concurrently with tidal <br />water conditions associated with coastal storm surge. This <br />greatly increases the probability of flooding in the low-lying <br />areas of the coastal zone. Areas along the Indian River are <br />particularly susceptible to flooding under these conditions. The <br />most flood prone areas in the eastern portion of the County <br />feature poorly drained soils, a high water table, and relatively <br />flat terrain, all of which contribute to their flooding problems. <br />Flat terrain and heavily wooded areas aggravate flood <br />problems by preventing rapid drainage in some areas. <br />Indian River County Comprehensive Emergency Management Plan Basic Page 8 <br />