FLOOD06680

• County: Statewide
• Basin: Statewide
• Title: Flood Damage in the United States, 1926-2000
• Date: 6/1/2000
• Prepared By: NOAA
• Floodplain - Doc Type: Flood Documentation Report

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Definition of Loss, Damage, and Damage Estimates
Researchers specializing in natural hazards have expressed a need for more complete
documentation of losses, including both direct and indirect costs associated with flooding (Mileti
1999; National Research Council 1999; Heinz Center 2000). Direct costs are closely connected
to a flood event and the resulting physical damage, In addition to immediate losses and repair
costs they include short-term costs stemming directly from the flood event, such as flood
fighting, temporary housing, and administrative assistance, By contrast, indirect costs are
incurred in an extended time period following a flood, They include loss of business and
personal income (including permanent loss of employment), reduction in property values,
increased insurance costs, loss of tax revenue, psychological trauma, and disturbance to
ecosystems. They tend to be more difficult to account for than direct costs (Heinz Center 2000),

The NWS describes its flood loss data as estimates of "direct damages" including, for
example, loss of property and crops and costs of repairing damaged buildings, roads, and
bridges. The NWS estimates have usually been restricted to direct physical damage, a subset of
the losses generally considered to be direct costs,

The dollar figures in the NWS damage data are estimates compiled soon after each flood
event, before the actual costs of repair and replacement can be known, They are not verified by
comparison with actual expenditures, The estimates are gathered from diverse sources, some
who use accurate estimation methods (e,g, insurance companies) and others who do not (e,g,
newspapers), Therefore, NWS damage data are best described, not as "loss data", but as
"damage estimates,"

D. Purpose and Methods
Objectives of this study are (1) to assemble a national database of historical flood damage
based on NWS damage estimates, making it as complete and consistent as possible; (2) to
describe what the estimates represent; (3) to evaluate the accuracy and consistency of the
estimates; and (4) to develop guidelines for use of the data and make it widely available to users,
Steps followed to achieve these objectives are described below,

1. Compilation of historical flood damage data sets.
The NWS Hydrologic Information Center (NWS-HIC) is responsible for compiling and
archiving flood damage estimates collected from NWS field offices throughout the U,S, Its staff
members provided several data sets and access to files and publications archived in their office at
Silver Spring, Maryland, This report augments published NWS data with information from
NWS files and reports of other federal and state agencies, The following data sets are presented:

a, Estimated flood damage in the United States (1926-1979 and 1983-2000, by fiscal year);
b. Estimated flood damage for each state in the U,S, (1955-1979, by calendar year, and 1983-
2000, by fiscal year); and
c, Estimated flood damage, by river basin and drainage, for the U,S, (1933-1975, by calendar
year),