Evaluating riverine flood policy: Land use planning trends in Aotearoa New Zealand

Globally, the responsibility to develop flood risk policy is often devolved to local government. However, local governments can lack the capacity to keep up with increasing and changing flood risk and information provision without external guidance and support. Central and state governments can deliver policy support and consistency by providing policy direction or standards based on best practice. Due to diverse localised modelling, plans and policies, there is often limited understanding of the nature of flood policy, the degree of variation between localities, and how authorities are improving practice and responding to increasing and changing risk. In this study, we develop and apply an evaluation tool for riverine flood planning that captures the modelling parameters, policies, and information used by regional authorities, distinguishing between traditional and emerging approaches. We examine three primary categories of regional flood policy: modelling parameters and associated planning regulations, risk-based policy approaches, and information provision processes. Our findings reveal evolving practices, policy variances, and aspects of contention, demonstrating where central and state governments can provide greater direction for policy development. Our evaluation tool therefore provides a basis to guide complex policy transitions, from static hazard-based planning towards a more comprehensive, risk-based approach. • Evaluation framework for regional riverine flood planning applicable in national jurisdictions. • Detailed modelling parameters and policy insights for flood planning practitioners and scholars. • Evidencing where governments can provide greater direction for riverine flood policy and risk management.