Introduction
The National Flood Insurance Program (NFIP) is $20.5 billion in debt to the U.S. Treasury (Lehmann, 2018), even after $16 billion in NFIP debt was cancelled in 2017 (Horn, 2019). The program has been in debt 24 of the past 38 years and has not been out of debt since 2005. An unintended consequence of its implementation has been the incentivization of floodplain development (Silvis, 2018). These facts underscore the reality that the U.S., and Louisiana in particular, is failing to address flood risk, and economic, physical, and social resilience to flood hazards remains unattainable under these circumstances.
A primary reason that these levels of flood losses continue and that community resilience remains elusive is that the “building code” standard fails to reduce flood damage sufficiently. The 1% annual probability event (APE) flood elevation [aka: base flood elevation (BFE)] is typically used as the design flood elevation (DFE). With no additional elevation (i.e., “freeboard”) to serve as added protection against flooding, the probability of APE being exceeded in 70 years (i.e., the useful life expectancy of a house) is 50.5%. Thus, without freeboard, half of all houses in the special flood hazard area (SFHA; area of the 1% APE flood) are expected to flood at least once, with 12% expected to flood twice, and nearly 3% expected to flood three times. The International Residential Code (IRC; 2014) provided the first nationally-recommended freeboard requirement for single-family homes; however, the Louisiana State Uniform Construction Code Council (LSUCCC, 2018, §103) removed this requirement for Louisiana. There remains no statewide-mandated freeboard in one of the most flood-prone states in the nation. How can we make progress toward resilient communities and economies if mathematics tells us that half of the homes located in the floodplain will flood at least once?
The solution appears simple: create and enforce freeboard standards. In an analysis of 450 U.S. communities participating in the Federal Emergency Management Agency’s (FEMA’s) Community Rating System (CRS; Zahran et al., 2010), Highfield and Brody (2013; 2017) found that freeboard requirements in the SFHA promote the most overall cost savings to flood damage, followed by open space protection and flood protection.
Therefore, the goal of this project, funded by Louisiana Sea Grant’s Omnibus Program, is to identify, evaluate, and address the economic, physical, personal perception, and policy incentives/barriers to increased freeboard for new home construction in Louisiana and communicate results with stakeholders.
Project research objectives are to:
1) collect freeboard incentive/barrier data from owners, renters, designers, builders, planners, and parish officials and analyze collected stakeholder data to characterize perspectives;
2) characterize flood probability functions at the parcel level considering climate variability across the study areas;
3) develop freeboard new construction cost and flood hazard life-cycle cost (LCC) models at the parcel level;
4) develop a web-based platform to disseminate economic aspects of increased freeboard;
5) identify potential solutions to freeboard barriers identified in Objective 1 (excluding economic barriers) with assistance from our Project Advisory Board (PAB);
6) widely disseminate project results with assistance from our PAB and outreach partners.