FLOOD02918

• County: Denver
• Community: Denver
• Stream Name: South Platte River
• Basin: South Platte
• Title: Estimation of Flood Depth-Damage Curves for Residential, Commercial and Industrial Properties in the Denver Region
• Date: 10/1/1977
• Prepared For: CWCB
• Prepared By: Wayne J. Grahm ‎(Master of Science Candidate at CSU)‎
• Floodplain - Doc Type: Educational/Technical/Reference Information

..
I
I-
I
I
I
I
I
I
Ie
I
I
I
I
I
I
I.
I
I

NEEP fOR fLOOP DEPTH-PAMAGE CURVES
.- - --

An accurate determination of damages resulting from different flood

events is needed for a variety of reasons. Four reasons for collecting

information on flood damages were given in 1966:

"First, it is important to know how much the Nation as
B whole is losing because of floods. Second, data on
individual floods, and especially large ones, are of
value in evaluating contemplated flood control works.
Third, a continuing record of actual flood losses at a
few selected points would provide a useful check on
the stage-damage relations used in evaluation of pro-
jects. Fourth, the most important use of flood damage
data in the future will be for planning the use of
flood plain lands, establishing land-use regulations,
and developing flood insurance programs." (Task Force
on Federal Flood Control Policy)

The need for damage data has increased with the implementation of

the National Flood Insurance Program (Flood Insurance Act of 1968 and

Flood Disaster Protection Act of 1973), When a community first joins the

Flood Insurance Program, flood insurance is made available for all walled

and roofed structures within the community boundaries. While the community

h in this "emergency" phase of the program, flood insurance is made avail-

, able at subsidized rates. These rates are the same for each community and

do not depend on the degree of hszard the property is exposed to. Later, a

detailed flood elevation study, called a Flood Insurance Study, is conducted.

The Federal Insurance Administration (FIA) then issues a rate map based upon

the study and any flood insurance covering a structure built after the effec-

tive date of the rate map (regular program entry date) can only be sold at

actuarial rates. Thus in the regular phase of the program, the rate is based

upon the average annual flood loss (AAFL) to the structure to which is added

administrative expenses, It is thus imperative that accurate depth-frequency

and depth-damage relationships be used to arrive at the AAFL,

2

'---~