Martin County, FL, Case Study: Physical and Economic Performance of Martin County Federal Shore Protection Project During 2004 Tropical Season. Flood and Coastal Storm Damage Reduction Program

摘要

This report presents the details of a case study analysis of the physical and economic performance of the Martin County Federal shore protection project during the 2004 tropical season. The goal of the analysis was to estimate the damages prevented by the shore protection project in Martin County over the 2004 tropical season, which brought two landfalling hurricanes across the southern end of Hutchinson Island just south of the project. Damages resulting from the combination of both hurricanes were estimated using Beach-fx for the known existing condition with the shore protection project in place and for an estimated without project condition. The without project condition was estimated by hindcasting shoreline and beach profile evolution from November 1995 through June 2004. Results of the analysis indicate that the Federal shore protection project at Martin County prevented approximately 9.7 million dollars more in property damages when compared to the with-project condition. In hindcasting the without project condition from 1996-2004, 9.2 million dollars in emergency protective actions including seawalls, revetments and construction of emergency dune features are estimated to have been constructed. The Martin County project cost $19.8 million ($14.3 million for initial construction and $5.5 million for renourishment) from 1996-2004. These estimates indicate the project prevented damages equal to half of the project cost in 20 days of 2004. These estimates do not include damages prevented by the project from 1996 up to the 2004 events, during which time 31 severe storms impacted the project area. Further, expected future damages avoided and costs over the remaining project life are not included. All of these estimates would be necessary to fully demonstrate the value of the project over the 50-year period of Federal participation.