Nature-based solutions with sponge functions: socio-economic importance and valuation

This article examines the socio-economic importance and valuation of different types of wetland restoration as nature-based solutions (NBS). Wetlands, like other NBS, generate positive externalities in the form of ecosystem services, with benefits accruing to a wide range of societal beneficiaries beyond landowners. However, the implementation of wetlands and other NBS is often constrained by several barriers, including limited awareness of their socio-economic benefits. Qualitative and quantitative assessments of ecosystem services can help address this gap by providing evidence-based arguments for public communication and decision-making. The study demonstrates such assessments using three case studies of wetlands implemented in different contexts: a rural wetland, an urban wetland, and large-scale floodplain restoration. Cost–benefit analysis is applied to illustrate how these measures can be evaluated and how their socio-economic feasibility can be communicated. In the first case study, the restoration of a natural pond with a wetland in Bratčice, Czech Republic, representing a rural wetland, the monetised benefits reach EUR 562,000 over a 25-year period and exceed costs by approximately EUR 60,000, with a payback period of 15 years. In the second case study, an urban wetland implemented as part of park revitalisation in Pilsen, Czech Republic, monetised benefits of EUR 14.2 million exceed costs by EUR 12.9 million over 25 years, resulting in a payback period of one year. For the floodplain restoration case study in Germany, the results indicate that, even without monetising the primary flood protection function, the economic case for large-scale restoration can be substantial. Monetising only a single benefit (nutrient retention) accounts for half or more of total costs, highlighting the relevance of conservative economic valuation for supporting investment decisions in wetland restoration. Wetlands are important nature-based solutions providing positive externalities; Results show that the monetised benefits significantly exceed the costs; Payback period for wetland case studies from a social perspective is 1 to 15 years; Socio-economic analysis offers arguments for planning and decision-making; Benefits in monetary terms are an important input for better communication.