Risk-based planning as long-term climate change adaptation

The impacts of the flood event in September 2024 demonstrated that building development in Lower Austria is not risk-adapted. New construction, additions, and building conversions in flood affected areas continuously increase the damage potential. Existing spatial planning regulations allow building land uses in potential flood-plains. In view of the initial estimate of damage amounts (€ 700 million for private households), it is clear that risk-based planning has not yet found its way into spatial planning and building law procedures - i.e. planning practice. Spatial planning restrictions for hazard areas have been in place in Lower Austria for decades, but the action plan of the Austrian Strategy for Adaptation to Climate Change emphasizes that further regulatory improvements in planning law should be under-taken to prevent natural hazards and adapt to climate change. The event in September 2024 also shows that there is not a regulatory deficit per se, but that the available hazard information and climate change-related dynamics in hazard frequencies and characteristics are not optimally integrated into spatial development - particularly at municipal level. Two central questions for RiskPlan can be derived from this: (i) Which legal adjustments in spatial planning and building law can promote risk-based planning and thus long-term adaptation? (ii) How can a professionally sound advisory service be organized that allows municipalities to make risk-based decisions regarding flood adaptation in spatial planning and building law? Methodologically, RiskPlan is based on an explorative approach. The legal analysis builds on a comparison of regulations in the federal states. The development of procedurally embedded advisory services is carried out in a transdisciplinary approach together with representatives of the authorities and planning consultants.