Nature-based solutions: From flood defense to addressing water scarcity and climate change risks

The adding pressures of climate change on natural resources are particularly obvious in water stressed areas and are introducing additional challenges related to water management, water availability and conservation of natural resources. Adaptation to the new climatic and socio-economic conditions requires innovative solutions with minimal impact on the already stressed resources and ecosystems. Following the principles of ecological engineering, solutions on rainwater harvesting and management, such as certain types of Sustainable Urban Drainage Systems, can form part of nature-based solutions. SUDS although have conventionally been used as options for flow attenuation, managing excess runoff and flood defense, they have a high potential for water reuse and drought management. This was happening due to the fact that they were originally implemented in geographic regions with significant levels of precipitation facing no drought issues. Recently such systems have been implemented in regions with water availability issues and in wetland, floodplains and riparian restoration efforts. Those options today are used so as to provide a new water resource of particular significance for the water scarce regions through the water storage and reuse potential they offer. The current paper is, therefore, aiming to present the water reuse element and the ways to achieve it through recognising the nature-based solutions as means to ensure water security, reduce the risks of climate change and of water scarcity and provide new options based on the principles of sustainability and circular economy.