Cost-effectiveness of federal CDBG-DR Road Home Program mitigation assistance in Jefferson Parish, Louisiana

Abstract After Hurricanes Katrina and Rita in 2005, the State of Louisiana received federal Community Development Block Grant Disaster Recovery (CDBG-DR) assistance, administered by Office (OCD) as Road Home Program, to provide homeowners with required matching funds for elevating damaged homes under Federal Emergency Management Agency (FEMA) Hazard Mitigation Program (HMGP). This research evaluates cost-effectiveness elevation mitigation assistance a case study Jefferson Parish, Louisiana, using benefit–cost analysis (BCA) based on average annual loss (AAL) prediction. We use multiple return period flood depths from FEMA RiskMAP non-regulatory depth calculate risk reduction difference between pre- post-elevation AAL. compute ratio (BCR) net (NBCR) investment across time horizons, considering several funding scenarios. Then, we determine optimal first-floor height (FFH) foundation type 100-year depth. The reveals that existing either 3 feet above ground or base (BFE; elevation), whichever is higher, reduces median AAL 98%. generates BCR 1.5 1.7 over 30-year mortgage 70-year building lifetime, respectively, if benefit allocated proportionately. These results enhance understanding investments, benefits minimum requirements, most effective elevated heights homes.