UNU CRIS will Co-host a session: S5 ‘Beyond water: Understanding the role and co-benefits of NBS [ Nature Based Solutions] used for water management

Abstract:

Nature-Based Solutions (NBS) have gained considerable popularity in the past years, as they are thought to be a reliable tool in the transition towards greener, more resilient and socially inclusive cities, while contributing to overturn the dominance of urban grey infrastructure (Lafortezza et al., 2018 and Castellar et al, 2021). According to Nika et al., (2020), NBS for water management have received a particularly high scholarly attention. NBS devoted to supporting urban water cycle include “units” dedicated to promoting water purification (e.g., constructed wetlands and vertical gardens), sustainable urban drainage (e.g., swale, ponds, rain gardens) among others. Moreover, NBS constitute a promising approach for onsite water treatment and reuse in cities. Even though NBS for urban water management are considered as multifunctional and capable of providing plenty of “co-benefits”- i.e., benefits adjacent to their main purpose of purification, storage, preventing runoff, etc. (Castellar et al, 2021) - there is still no agreement on how to measure or estimate these co-benefits. The ecosystem services concept and methods, developed and continuously improved by its active community, might provide useful tools to assess and measure such NBS’ benefits and to contribute to a sustainable environmental management. In this regard, the ESP Working Group S5 – ES in Water Management has recently published a special issue on “Incorporating ecosystem services into water resource management” in Environmental Management, Springer. The issue highlights the important role of ecosystem services in integrated water resource management as A) flexible concept and a way to connect with stakeholders, B) useful tool to engage in participatory processes and capacity building, C) assessment method for reflecting the plurality of values of the environment, D) decision-support system for environmental analysis (Vollmer et al. 2022). Still, the uncertainty under which the decision-making process operates makes it challenging to accept and rely on the implementation of innovative concepts and methods, including nature-based solutions, less engineering and less centralised approaches. There is significant uncertainty brought about by assessment tools (incl. ES assessments) and decision-making support models (Hou et al. 2013). Furthermore, externalities such as the uncertainty of the socio-economic (incl. pandemic, war, geopolitical hegemonies, political priorities) and environmental (incl. climate change impacts, biodiversity loss) factors influence the prospects of the future, under which decisions should be taken.