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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 hydro meteorological 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 2007 dollars.  The Construction Cost Index is obtained from McGraw Hill Construction; Engineering News-Record http://enr.ecnext.com/coms2/summary_0271-38083_ITM  - subscription required  (http://enr.construction.com/features/conEco/costIndexes/default.asp) Please note that the last column is reported in billions of dollars.  The data are also provided in graphical form. Year Unadjusted Damages (K) CCI Index Adjustment Factor Adjusted Damages (Billion) 1903 $53,116 95 83.85 $4.454 1904 $6,545 95 83.85 $0.549 1905 $11,000 95 83.85 $0.922 1906 $400 95 83.85 $0.034 1907 $15,576 101 78.87 $1.228 1908 $10,250 97 82.12 $1.027 1909 $49,134 91 87.54 $4.301 1910 $21,239 96 82.98 $1.762 1911 $7,772 93 85.66 $0.666 1912 $77,586 91 87.54 $6.792 1913 $171,387 100 79.66 $13.653 1914 $17,951 89 89.51 $1.607 1915 $14,131 93 85.66 $1.210 1916 $26,124 130 61.28 $1.601 1917 $27,330 181 44.01 $1.203 1918 $7,867 189 42.15 $0.332 1919 $3,164 198 40.23 $0.128 1920 $24,771 251 31.74 $0.786 1921 $28,647 202 39.44 $1.130 1922 $52,060 174 45.78 $2.383 1923 $52,905 214 37.22 $1.969 1924 $16,979 215 37.05 $0.629 1925 $9,923 207 38.48 $0.382 1926 $23,468 208 38.30 $0.899 1927 $347,656 206 38.67 $13.444 1928 $44,611 207 38.48 $1.717 1929 $68,098 207 38.48 $2.620 1930 $15,850 203 39.24 $0.622 1931 $2,808 181 44.01 $0.124 1932 $10,295 157 50.74 $0.522 1933 $36,679 170 46.86 $1.719 1934 $10,362 198 40.23 $0.417 1935 $127,127 196 40.64 $5.166 1936 $282,549 206 38.67 $10.926 1937 $440,730 235 33.90 $14.941 1938 $101,098 236 33.75 $3.412 1939 $13,834 236 33.75 $0.467 1940 $40,467 242 32.92 $1.332 1941 $39,524 258 30.88 $1.221 1942 $98,507 276 28.86 $2.843 1943 $199,732 290 27.47 $5.487 1944 $101,079 299 26.64 $2.693 1945 $165,796 308 28.86 $4.785 1946 $70,813 346 23.02 $1.630 1947 $272,328 413 19.29 $5.253 1948 $229,959 461 17.28 $3.974 1949 $93,931 477 16.70 $1.569 1950 $176,050 510 15.62 $2.750 1951 $1,028,741 543 14.67 $15.092 1952 $254,064 569 14.00 $3.557 1953 $122,204 600 13.28 $1.623 1954 $106,842 628 12.68 $1.355 1955 $995,491 660 12.07 $12.016 1956 $64,688 692 11.51 $0.745 1957 $360,303 724 11.00 $3.963 1958 $218,255 759 10.50 $2.292 1959 $141,255 797 9.99 $1.411 1960 $92,976 824 9.67 $0.899 1961 $154,033 847 9.40 $1.448 1962 $75,237 872 9.14 $0.688 1963 $177,946 901 8.84 $1.573 1964 $651,642 936 8.51 $5.545 1965 $788,046 971 8.20 $6.462 1966 $117,004 1019 7.82 $0.915 1967 $375,218 1074 7.42 $2.784 1968 $339,399 1155 6.90 $2.342 1969 $902,654 1269 6.28 $5.669 1970 $225,453 1381 5.77 $1.301 1971 $287,525 1581 5.04 $1.449 1972 $4,465,135 1753 4.54 $20.272 1973 $1,894,493 1895 4.20 $7.957 1974 $576,203 2020 3.94 $2.270 1975 $1,373,269 2212 3.60 $4.944 1976 $3,000,000 2401 3.32 $9.960 1977 $1,300,000 2576 3.09 $4.017 1978 $700,000 2776 2.87 $2.009 1979 $3,500,000 3003 2.65 $9.275 1980 $1,500,000 3237 2.46 $3.690 1981 $1,000,000 3535 2.25 $2.250 1982 $2,500,000 3825 2.08 $5.200 1983 $4,000,000 4066 1.96 $7.840 1984 $3,750,000  4148 1.92 $7.200 1985 $500,000  4182 1.90 $0.950 1986 $6,000,000 4295 1.85 $11.100 1987 $1,444,199 4406 1.81 $2.614 1988 $225,298 4519 1.76 $0.397 1989 $1,080,814 4615 1.73 $1.870 1990 $1,636,431 4732 1.68 $2.749 1991 $1,698,781 4835 1.65 $2.803 1992 $762,762 4985 1.60 $1.220 1993 $16,370,010 5210 1.53 $25.046 1994 $1,120,309 5408 1.47 $1.647 1995 $5,110,829 5471 1.46 $7.462 1996 $6,121,884 5620 1.42 $8.693 1997 $8,730,407 5826 1.37 $11.961 1998 $2,496,960 5920 1.35 $3.371 1999 $5,455,263 6059 1.31 $7.146 2000 $1,338,735 6221 1.28 $1.714 2001 $7,309,308  6334 1.26 $9.210 2002 $1,211,339 6538 1.22 $1.478 2003 $2,482,230  6695 1.19 $2.954 2004 $13,970,646 7115 1.12 $15.647 2005 $42,010,435 see note below 7446 1.07 $44.951 2006 3,744,636 7751 1.03 $3.857 2007 2,609,160 7966 1.00 $2.609   IMPORTANT NOTE CONCERNING WY2005 DAMAGE ESTIMATES AND HURRICANES KATRINA AND RITA: The devastation and loss of life associated with Hurricanes Katrina and Rita are extensive and hard to quantify. Determining the total damage caused by these storms, let alone allocating the portion due to flooding is extremely difficult. The following discussion is intended to provide the process involved in creating this best available estimate of flood damages caused by these storms. Estimates of losses caused by Katrina range from 100 billion to 150 billion, as compiled by the National Climatic Data Center ( http://www.ncdc.noaa.gov/oa/reports/tech-report-200501z.pdf ). The National Hurricane Center has a lower estimate (http://www.nhc.noaa.gov/pdf/TCR-AL122005_Katrina.pdf). Additionally, Dr. Roger Pielke, Jr., who has done significant research concerning the determination of flooding related losses has an assessment of the damages between 100 and 150 billion (http://sciencepolicy.colorado.edu/prometheus/archives/disasters/000563part_ii_historical.html). Several other articles from related industry sources support this estimate (approximately $125 billion). These can be found at: http://www.sfgate.com/cgi-bin/article.cgi?file=/chronicle/archive/2005/09/27/BUGADEUAO01.DTL http://www.construction.com/AboutUs/20050909pr.asp http://www.swlaw.com/publications/files/11-05_Client_Alert_Post_Katrina_RWM.pdf We chose $125 billion as a reasonable starting point to estimate the flooding related losses caused by Katrina. Damage from hurricanes can be divided into 3 general categories, storm surge, wind, and flooding. For Hurricane Katrina, where an estimated 80% of New Orleans ended up flooded, it is unclear to what degree the storm surge caused the widespread flooding. Much of the damage to Mississippi was typical of that caused by storm surge, reducing the relative portion attributable to flooding and wind. As a rough estimate, we allocate 60% of the total damage to storm surge, or $75 billion; 30% due to flooding, or $37.5 billion; and 10% to wind damage, or $12.5 billion. Hurricane Rita occurred at the end of the Water Year, making landfall on September 24th, 2005. The preliminary insured damages estimates range from $4 to 5 billion (http://www.ncdc.noaa.gov/oa/climate/research/2005/rita.html). Our current best estimate of total damages is about $9 billion. Wind related damages were a larger proportion of these damages, so we estimate that the damages should be divided approximately equally between storm surge, wind and flooding, resulting in a preliminary estimate of $3 billion in flooding damages, spread between Texas and Louisiana.