FLOOD07152

• County: Delta
• Community: Orchard City
• Stream Name: Sruface Creek, Cedar Run, Tongue Creek
• Basin: Gunnison
• Title: Orchard City, Colorado 100-Year Floodplain Delineation
• Date: 2/20/2003
• Prepared For: CWCB
• Prepared By: Gared Grube, Thomas Gilman
• Floodplain - Doc Type: Floodplain Report/Masterplan

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safe from some type of damaging flood event" (Browning, 2002). There have been 267
communities in all of Colorado's 63 counties that have been identified in flood prone areas
(CWCB 2002),

A flood event can cause catastrophic damage if preparation and pre-disaster mitigation is not
made, The goal of pre-disaster mitigation is to reduce the loss of life, human suffering, economic
disruption, and disaster cost to the federal taxpayer. In other words, to reduce the vulnerability
of the community before the next disaster threatens (FEMA, 2002), The economic expense from
property damage and post-disaster clean up, as well as the loss of life, can be significantly
reduced by implementing floodplain management.

In order to prove that the post-disaster expense in fact does greatly exceed the pre-disaster
mitigation expense, Grimm (1998) examined the 1997 Spring Creek flood in Fort Collins,
Colorado, This 500-year flash flood event occurred on July 28, 1997 as a result of a convective
storm and resulted in five deaths, 62 hospitalizations, and more than $250 million in property
damage (Weaver et ai" 2000). In the decade prior to the flood, the City of Fort Collins spent $5
million in pre-disaster mitigation efforts that include removing 86 structures (45 of which were
residential or commercial) from the I GO-year floodplain, The removal of these structures is
estimated to have saved 98 lives and $8.4 to $14,5 million, The total bill for damages based on
this assessment is estimated to have reduced the total bill by $5,6 to $9 million, This analysis
does not include other mitigation efforts, such as education, included in the $5 million budget.
Therefore, it can be concluded that the pre-disaster mitigation efforts were very much worth the
cost (Grimm, 1998).

One of the most effective methods of flood hazard reduction is to delineate a floodplain map of a
community, At minimum, a 100-year floodplain should be determined for all communities. The
100-year floodplain is used since it has a I % probably of occurring in any given year and has
significance for floodplain management and insurance purposes, It is the 100-year flood plain
that is the minimum standard for regulatory floodplain information as determined by the Federal
Emergency Management Agency (FEMA, 2002),

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