FLOOD01659

• County: Statewide
• Title: Floodplain Management Handbook
• Date: 9/1/1981
• Prepared By: Flood Loss Reduction Associates
• Floodplain - Doc Type: Floodplain Report/Masterplan

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Flood preparedness plans describe
and assign responsibility for carrying
out preplanned actions for minimizing
loss of life and property during a
flood. These plans usually provide for
evacuation, emergency flood protection
and flood fighting. They also include
arrangements to care for evacuees and
speed recovery of the community.
Preparedness plans customarily are
drawn up for use by a specific city or
county and linked to the area's flood
warning system.

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Flood warning systems can be
designed to deal with most types of
flood problems. One of their primary
uses is protection of life in areas
subject to flash flooding. The extent
of damage prevention enabled by a flood
warning system is related to the length
of warning time it provides. The longer
the warning time, the more possibili-
ties there are for preventing damage.
Warning systems are essential for some
types of flood protection that require
action immediately before a flood to
make them effective. They are also
useful in conjunction with the
operation and safety of dams, levees
and other measures providing only a
limited level of protection or posing a
risk of failure.

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The cost of a flood warning
system depends largely on the method
used for collecting and analyzing
precipitation and stream level data and
the amounts of data collected. Systems
using volunteer observers are inexpen-
si ve while systems using automatic
gages moni tored by computers may cost
tens of thousands of dollars. Basic
preparedness plans are primarily organi-
zational arrangements and so involve
little cost to the community beyond the
time required for their original
development. Some recurring expenses
are involved, however, for updating,
familiarizing officials with their
provisions, and conducting drills.

Floodprooflng

The concept of floodproofing (or
more accurately, flood resistent
construction practices) is to modify

buildings, their sites or their con-
tents to keep water out or reduce the
damage caused by water entry. Flood-
proofing also can be used to reduce
disruption to activities, to maintain
vital services in operation during a
flood, and to permit faster recovery
from flooding.

The site for these
raised with fill to
of potential floods.

structures
above the

was
level

Unlike dams and other measures
protecting large areas or long sections
of streams, floodproofing is used to
protect individual buildings or small
groups of buildings. Floodproofing is
most easily incorporated in new con-
struction since it may often be
included at little or no additional
cost. However, it's addition to exist-
ing structures may be economical in
some cases. A large number of flood-
proofing techniques are available. The
most common ones are described below.

The most frequently used method
of flood proofing is the elevation of
buildings above expected flood levels.
Existing structures can sometimes be
raised and the original foundation
extended upward with walls, piers or
posts. These measures are best suited
for smaller structures with basements
or crawl spaces. A common way to
elevate a new structure above flood
levels is to raise the elevation of the
site with earth fill. New structures
can also be raised above the ground on
columns or walls.

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