Watershed Master Planning Tools to Support National Flood Insurance Program and Community Rating System Goals for Lowering Insurance Premiums for At-Risk Communities

This paper is intended for a broad audience interested in sub-watershed level master planning. According to the Community Rating System (CRS) data released in April 2021 by the National Flood Insurance Program (NFIP), 89.5% (1544 out of 1725) of all eligible CRS communities in the United States have a current CRS class of 5 or higher. Many of these communities have not improved their rating beyond Class 5 mainly due to the perceived limitation associated with the watershed master plan (WMP) credit. To address this barrier, the Federal Emergency Management Agency (FEMA), the Florida Division of Emergency Management (FDEM), and Florida Atlantic University's Center for Water Resiliency and Risk Reduction (FAU CWR3) embarked on a project to create a framework and guidance for a standardized template for watershed master planning along with a web-based clearinghouse to assist in master planning at the sub-watershed level. The project developed two prototype WMPs (one coastal and one inland) which were reviewed by a CRS review team and determined to be creditable under the CRS 2021 addendum. These plans included detailed approaches to watershed characterization, policy frameworks, model ordinances, and collection of comprehensive curated data sets needed for modeling of Hydrologic Unit Code-12 (HUC-12) sub-watersheds (i.e. topographic data, groundwater/surface water/tides/sea level rise, soils data, land use/land cover, precipitation record, open space/impervious areas/waterbodies/wetlands, locations of stormwater infrastructure, natural resources, and demographics). In addition, FAU CWR3 developed a screening framework for open-source hydrologic modeling to estimate probability of inundation taking into account king tides, future land use changes, sea level rise, and various design storms. The inundation probabilities were then incorporated into an artificial intelligence tiered prioritization tool for implementation of mitigation strategies. This tool utilizes US Department of Revenue codes at the parcel level, potential economic loss, and repetitive loss properties. This paper will introduce readers to the resources and tools developed to make the watershed master planning process more streamlined and accessible to more communities. Furthermore, FDEM is planning to offer an incentive grant program in 2022 to stimulate more adoption of these plans in Florida to improve flood insurance discounts, and the authors will present more details about this program.