Flood Losses

Compilation of Flood Loss Statistics

The flood loss information provided below can only be considered approximate. There is no one agency in the United States with specific responsibility for collecting and evaluating detailed flood loss information. The National Weather Service (NWS), through its numerous field offices provides loss estimates for significant flooding events. However, this task is ancillary to the prime mission of the NWS which is to provide forecasts and warnings of hydrometeorological events. The Agency's focus is on predicting the events that lead to death and damage, rather than on an assessment of the consequences of the events it predicts. Because of this, the quality of resulting flood loss estimates may be uneven, depending on other operational constraints at a particular field offices.

Accurate flood loss estimates would require a concerted effort, based on the availability of substantial resources. There is no central clearinghouse to report flood losses. Our societal infrastructure almost guarantees poor estimates. State and municipal losses are often self-insured. Some portion of the cost to repair a washed out road or bridge might be covered in a budget line item for routine maintenance. Another portion may be financed by a separate line item in the next year's budget. In some cases, a structure may be replaced by one of higher quality, costing more than the replacement value or repair costs of the original structure. Finally, for situations where a governmental entity (city, county, state, etc.) carries no third party insurance, it may decide to forgo some repairs.

For homeowners and businesses, some will either not have insurance or be under insured. The costs for this sort of repair is almost impossible to establish. For those that are insured, claims may not fully reflect actual losses. Agricultural losses are also hard to accurately estimate.

Loss/damage estimates are reported in many different ways. Totals are may be available on state and county levels. Depending on who is providing them, they may not comprehensively include all damages. In addition, industry-wide estimates (e.g., river transportation/barges, railroads, etc.) covering multiple states are often available. Funding and aid supplied by various agencies of the Federal government may also provide information on losses (e.g., FEMA, Dept. of Agriculture, Small Business Administration, etc.) over a region. Often, there is usually not enough information to easily determine the degree of overlap among these various sources of loss estimates. Flood losses that "fall between the cracks" of the current system could, however, compensate for possible "double counting."  Unfortunately, there is usually no easy way to reconcile information from different reporting systems.

Finally, deciding what constitutes a loss is not always as simple as it might seem. Certainly the capital cost to repair or replace a bridge that has been washed out is easily identified as a loss. However, if flooding prevents a farmer from planting a crop, what is the value of the loss. The farmer may not have experienced a loss literally, since he did not plant a crop and did not lose the crop but he may have been denied potential income. What if he/she planted later in the season and had reduced yield because of a shorter growing period or because he/she chose to plant a lower-profit crop? How is this loss calculated?

In another example, what about the barge operator or the business owner who has to cease operations? In addition to the business owner's repair costs there are his lost income, and the lost income of his employees who may be laid off. In order to make this wide range of economic impacts due to flooding tractable, loss statistics can be partitioned into direct and indirect damages. Direct damages are the costs to repair such things as damaged buildings, washed out railroad beds, bridges, etc. Indirect damages include such categories as lost wages because of business closures. There is no universally agreed upon demarcation between what constitutes a direct and an indirect loss.

The above factors only highlight some of the more significant impediments to accurate determination of flood losses. In the case of NWS loss estimates, what is included is the "best estimate" of direct damages due to flooding that results from rainfall and/or snowmelt. It does not include flooding due to winds, such as coastal flooding (e.g., hurricane storm surges). Because of the complexity of the problems and the limited resources available for extensive evaluation of the quality of the data, the estimates provided here should only be considered approximate.

In the table below, the data are for water years, starting in October and ending in September.  For example, Water Year 1993 starts on October 1, 1992, and ends on September 30, 1993. The quality of the older data is subject to some question. The more recent data are generally more reliable, but while the damage amounts for individual years are not precise, they provide reasonable indications of relative changes over time.

The damage figures in the second column are in thousands of dollars. The second column provides "unadjusted" damage amounts. That is, the damage as reported in the year it occurred, not adjusted for inflation. The third column is a Construction Cost Index, used to adjust for inflation. The next column to the right is the adjustment factor applied to the unadjusted estimates to get the column damages estimates "adjusted" to 1997 dollars.  Please note that the last column is reported in billions of dollars.  The data are also provided in graphical form.

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Last Modified: March 08, 2000