hh, RECURRING DA11AGES 



Estimates have been made of the damages for flood stages equi- 

 valent to those of the 1938, 19hhj 195U and design hxirricanes and 

 for other recent hurricanes and severe storms based on stage-damage 

 relationships obtained from the damage surveys. These recurring 

 losses are sximmarized in Table 8 at 19^6 price levels. In the 

 development of recurring losses allowances have been nade for (l) 

 the anticipated effectiveness of individual plant flood protection, 



(2) the recovery of loss potential at property completely destroyed, 



(3) a general change in price levels due to increased costs, and 

 (U) the estimated economic growth of the area, 



U5. AVERAGE ANNUAL LOSSES 



Average annual tidal flood losses in the Narragansett Bay area 

 have been estimated at $^,922,000 at 19^6 price levels. These losses 

 were derived by correlating stage -damage, stage-frequency and damage- 

 frequency curves in accordance with standard practice, A stage-fre- 

 quency curve, based upon the knovm peak elevations of recent hurri- 

 canes and hif;h water and peak elevations estimated from historical 

 data of flood- producing storms of the past 321 years, vias correlated 

 with stage-damage relationships, referenced to the 195h hurricane 

 tidal-flood crest, to arrive at damage-frequency curves, as described 

 in Appendix D. 



In view of the lack of precedent for estiriiating annual losses 

 due to tidal floodin/^, an alternative method of estimating annual 

 losses was used for cofjparison, based upon the assumption of a reciir- 

 rnnce within the next 50 years, under^ economic conditions. existing 

 in 1956, of the hurricanes of 1938, 19UU, and IS^k, and 22 flood- 

 producing storms, A recurrence of the flood stages of these hurri- 

 canes and storms within the next 50 years in the protected area 

 would cause an estimated total loss of ^227,200,000, or an average 

 annual loss of ipU,5U+>000 in the 50-year period. The annual loss 

 derived by this method is comparable to that derived by the fre- 

 quency method, 



U6, SCARE COSTS 



In addition to damages from tidal flooding, losses are incurred 

 in the flood area by the institution of temporary preventive meas- 

 ures upon advice of hurricane warnings, whether flooding occurs or 

 not. Scare costs of a single hurricane warning are estimated at 

 5325,000, Based on a frequency of three hurricane warnings in a 10- 

 y«ar period, average annual scare costs amount to $98,000. Appen- 

 dix D discusses in detail the derivation of recurring losses, an- 

 nual losses and scare costs. 



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