FLOOD02417

• County: Statewide
• Basin: Statewide
• Title: Guidelines on Community Local Flood Warning and Response Systems
• Date: 8/1/1985
• Prepared For: US
• Prepared By: Hydrology Subcommittee
• Floodplain - Doc Type: Flood Mitigation/Flood Warning/Watershed Restoration

B.3. Flood Loss Potentisl

Evaluating flood loss potential is an important step in determining the need

for a local flood warning system. Flood loss potential, as used here, is the

potential for loss of life and property damage from the occurrence of various

magnitudes of floods. Evaluating flood loss potential consists of assessing

the resident population and damageable property located on the flood plain

that would be directly affected by flooding. Many communities have
established stage-damage charts that show the relationship between river stage

and flood damages (see Figure 5). These charts must be kept up to date to

reflect changes in urban development. The relationship of river stage to

inundation area is important in determining flood loss potential. Community

flood studies, such as those developed for flood insurance, provide profiles
and maps that reveal the magnitude of flooding expected and permit the

identification of critical public services that are vulnerable to flooding.

.

.

A number of questions must be answered when evaluating flood loss potential.

Is there a potential for loss of life associated with floods? What structures

are located within the flood plain? What are the annual flood damages? What

is the potential flood damage for a particularly severe flood such as the 1-

percent-chance flood? Where are the evacuation routes in relation to the area

of inundation?

p

In many instances, data are not available to answer all of these questions,

but the more questions that can be answered, the more certainty there will be

determining both the need for a local warning system and the cost effective-

ness of a particular warning system. Cost effectiveness is calculated by

16