Nature‑based Solutions (NbS) are increasingly promoted as multifunctional interventions capable of delivering ecological, social, and economic co‑benefits while addressing complex water‑management challenges. Yet, despite their growing prominence, the practical question facing many planners, asset owners, and policy makers remains: When is an NbS the right solution and when is it not? This paper examines the decision context surrounding the selection, design, implementation, and risks of NbS within contemporary water and catchment management frameworks.
Drawing on recent examples from urban stormwater systems, flood mitigation projects, and landscape‑scale restoration initiatives, we explore the conditions that influence NbS performance, longevity, and cost‑effectiveness. These include hydrologic suitability, land availability, maintenance capacity, regulatory drivers, community expectations, and alignment with existing infrastructure. We also highlight scenarios where NbS may underperform or introduce unintended consequences, such as increased operational complexity, uncertain long‑term function, or misalignment with organisational risk tolerances.
To support engineering and risk‑based decision‑making, we propose a structured assessment framework that emphasises integrated solutions and focuses on defining desired or acceptable outcomes first. The framework encourages transparent evaluation of trade‑offs, quantification of ecosystem service benefits, and clearer articulation of long-term monitoring requirements.
Ultimately, the use of NbS can be maximised appropriately through context‑specific application supported by robust engineering, multi‑disciplinary collaboration, and adaptive governance. Asking “to Nature‑Based Solution or not?” is therefore essential - not to limit innovation, but to ensure that NbS are positioned where they are most capable of delivering appropriate, meaningful, and measurable long-term benefits.