FLOOD08745

• County: Statewide
• Community: Statewide
• Basin: Statewide
• Title: Colorado Flood Hazard Mitigation Plan
• Date: 12/1/1999
• Prepared For: State of Colorado
• Prepared By: Kistner and Associates
• Floodplain - Doc Type: Flood Mitigation/Flood Warning/Watershed Restoration

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Colorado Flood Hazard Mitigation Plan -1999

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Chapter 2 - Hazard Identification and Evaluation I
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2.1 People and Hazards
The relationship between flood hazards and population
identifies patterns of risk, as shown in Figure 2,1, Re-
lationships between patterns of risk and steps taken
toward preparedness explain degrees of vulnerability
to which various Coloradans are exposed,

Such relationships are not new to Colorado, The natu-
ral phenomena involved have occurred here long be-
fore people settled near them and were impacted by
them, Risk grows from the increasingly close associa-
tion between natural phenomena and a growing popu-
lation,

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Figure 2.1-Relationships to Risk

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People become vulnerable to hazards when they
choose (knowingly or unknowingly) to live near the ar-
eas where these extreme events occur. Vulnerabilrty
is also related to preparedness, People who prepare
for the occurrence of an extreme event are less vulner-

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For lIare IDlonnaUOD

Appendix A" Includes definitions, acronyms.
and references used in the
preparation of this plan,
Appendfx B - Includes information on financial
assistance programs,
Appendix C - Includes tips to minimize loss of
I~e & property in the event of a
flood,

Appendix D - Includes mitigation strategies and
measures.
Appendix E - Includes mrtigation planning
examples,

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Chapter 2 - 1

able to rt than those who do not The vulnerability of
Colorado's population is rooted in a relationship be-
tween the occurrences of extreme events, the prox-
imity of poople to these occurrences, and the degree
to which these people are prepared to cope with these
extremes of nature,

Today. f100d prone areas have been identified in 268
crties and towns and in all of the 63 counties in Colo-
rado, Using information supplied from local unrts of
government there are estimated to be approximately
250,000 people now living in Colorado's floodplains,
The Colorado Water Conservation Board (CWCB) esti-
mates that approximately 65.000 homes and 15,000
commercial and industrial business structures are lo-
cated in Colorado's fioodplains, Note: One of the rec-
ommendations of this plan is to begin to inventory the
structures and people in Colorado's floodplain, This
inventory, when completed, will enable planners at the
state and local level of governments to plan and miti-
gate the flood hazard, The total value of property. in-
cluding structures and contents. exposed to the 100-
year flood in Colorado is estimated to be over $11 bil-
lion dollars, Cumulative flood losses from the tum of
the century to 1999 from the state's most damaging
floods are $4.4 billion (1999 dollars),

2.2 Types of Hazards

2.2.1 Floods
Floods in Colorado occur on "riverine" systems con-
sisting of a basin (or watershed) and a hierarchical or-
der of stream channels that convey the normal flow of
water through the watershed, The area adjacent to the
channel is the floodplain, Flooding resurts when the
flow of water is greater than the normal carrying ca-
pacity of the stream channel. Rate of rise. magnrtude
(or peak discharge), duration, and frequency of floods
are a function of specific physiographic characteristics,
Generally the rise in water surface elevation is qurte

Flood:

Webster's DalinilieDs

a temporary condition of
inundation of normally dry
land areas
a source of danger
to cause to become less
harsh or hostile, to make
less severe

Hazard:
MItigate:

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