Abstract Summary
Circular economy has been proposed as a solution to tackle challenges and versatile stressors faced by the water sector, including climate change, water scarcity, water pollution, and resource depletion, thereby offering a promising pathway towards attaining sustainable development goals and enhancing climate resilience. While circularity has been conceptually associated with resilience and sustainability, existing studies are sparse, fragmented, and highly theoretical, lacking clear conceptualization and failing to provide practical guidance on utilizing these concepts to guide water systems planning and management. By carrying out a systematic literature review, this paper aims to tackle the following objectives: (1) conceptualize resilience and sustainability in the context of the circular water economy, (2) unveil the effects of circularity-enhancing interventions on the sustainability and resilience of water systems, and (3) clarify the influence of the interventions on pressures and emerging threats confronting the water sector. Circularity strategies employed in existing studies regard water (i) as a service, promoting water recovery, reuse, and recycling, and water (ii) as a source of energy and materials carrier, aiming to resource recovery and energy production from water and wastewater streams. Preliminary findings reveal that utilization of alternative water sources fosters diversification of water resources and is considered to enhance the reliability and resiliency of water supply services by reducing their dependency on freshwater resources and serving as reserve capacity in the face of water scarcity while also decreasing freshwater withdrawals. Valorization of wastewater streams for materials recovery and energy production decreases wastewater discharge and ecosystem degradation and offers alternative resources and energy supplies, decreasing dependency on primary resources and limiting their depletion. The findings indicate that incorporating resilience and sustainability in water systems management is essential for ensuring the reliability of water services in the face of emerging threats to water supply while serving Sustainable Development Goals, out of which are strengthened climate resilience and adaptive capacity, access to clean water and energy, reduced water pollution, and conservation of water resources. The state-of-the-art literature review aims to bridge the gap in conceptual clarity on the effects of the circular economy on water systems’ resilience and sustainability and to provide insights to policymakers and practitioners on how these concepts can be utilized to inform water systems planning. Future research should explore how these concepts can be practically applied to water systems design and management by translating the theoretical findings of the systematic review into actionable advice. Further, future research should focus on operationalizing these concepts to specify how resilience and sustainability can be measured as system properties, to facilitate their use in designing and assessing circular water systems, and to enable empirical testing.
