Adaptation pathways for climate change mitigation using nature-based solutions: assessing retention ponds for flood hazard mitigation in the Tamnava Basin

As climate change exacerbates water-related hazards in rural and urban areas, the need for robust, flexible solutions to mitigate risks and enhance resilience has become increasingly urgent. Traditional ‘grey’ infrastructure has long dominated flood risk management; however, nature-based solutions (NBS) are gaining traction due to their adaptability, multifunctionality, and ability to provide co-benefits. This study quantified the effectiveness of retention ponds as NBS for reducing flood hazard and risk under current and future climate conditions, employing adaptive pathways and tipping point frameworks for implementing NBS measures in response to climate change. This was applied in Tamnava Basin, Serbia, using a three-step approach: development of future sub-daily rainfall depth–duration–frequency curves (DDF), NBS performance assessment and identification of tipping points and development of adaptive pathways. Coupling HEC-HMS and HEC-RAS models with GIS tools, the study estimated reductions in flood area, volume, and damage costs by 20–27%, 28–35%, and 40–47%, respectively, over the period from the present to 2100, depending on the retention pond configurations. Different adaptive pathway maps were developed, for rainfall return periods. These maps provide decision-makers with flexible, actionable options for implementing NBS measures, bridging the gap between short-term evaluations and long-term climate uncertainties.