The Proof of the Planning Is in the Platting: An Evaluation of Floridaʹs Hurricane Exposure Mitigation Planning Mandate

Problem: Floridaʹs 1985 Growth Management Act required the stateʹs coastal communities to include policies for two types of hurricane hazard zones in their comprehensive plans: to direct populations away from coastal high hazard areas (CHHAs) and to maintain evacuation times within larger hurricane vulnerability zones (HVZs). State law requires local governments to initiate measures to implement these policies within one year of state approval of the local plan. Have communities complied with these state mandates? Purpose: This research aims to determine the extent to which post-plan residential development intensities within hurricane hazard zones conform to the stateʹs policy mandate and the degree to which success in this regard can be explained by the quality of local plan maps and policies. Methods: We conducted graphical analysis of development trends, and undertook quasi-experimental analysis of pre- and post-plan residential development inside and outside CHHAs, as well as analyzing correlations between plan quality and post-plan residential development intensity. We also conducted interviews for case studies. Results and conclusions: We found residential exposure to hurricane flood hazards to have increased substantially in the majority of 74 municipalities and 15 coastal counties in Florida after the state approved local comprehensive plans. Residential development inside CHHAs did not slow after plans were adopted by most of these coastal communities. We found better maps and stronger policies to be correlated with lower post-plan development intensity, but the policy quality effect, though not the map quality effect, disappeared after controlling for pre-plan development intensities. These results may be due in part to vesting of development approved prior to adopting the plans, pre-existing zoning entitlements, and Floridaʹs 1995 property rights law. Takeaway for practice: State planning mandates aimed at managing development in critical areas are likely to have only marginal effects because of prior entitlements and the legal and political inertia of existing local plan policies and land development regulations. Research support: Research support was received from the National Oceanic and Atmospheric Administrationʹs Office of Sea Grant, the Florida Department of Community Affairs, and Florida State Universityʹs DeVoe Moore Center.