Flood Damage Data

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Flood Damage in the United States, 1926-2003
A Reanalysis of National Weather Service Estimates.

About this Website

photoFlood damage has increased in the United States, despite local efforts and federal encouragement to mitigate flood hazards and regulate development in flood-prone areas. To help researchers and policy makers assess national progress in reducing vulnerability to flood hazards, reasonably accurate assessments of flood damage are needed. Yet, accurate accounting for losses has historically received little attention, except in the case of insured property.

The National Weather Service (NWS) is the only organization that has maintained a reasonably consistent long-term record of flood damage throughout the U.S. The NWS damage estimates do not represent an accurate accounting of actual costs, nor do they include all of the losses that might be attributable to flooding. Rather, they are rough estimates of direct physical damage to property, crops, and public infrastructure.

The flood damage estimates presented in this website are compiled from NWS records and publications, supplemented by reports of other federal and state agencies. The accompanying report includes an evaluation of the accuracy of the estimates and recommendations for users of the data. Users should be aware that estimates for individual flood events are often quite inaccurate. However, when estimates from many events are added together the errors become proportionately smaller. When properly used, the reanalyzed NWS damage estimates can be a valuable tool to aid researchers and decision makers in understanding the changing character of damaging floods in the U.S.

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