Conceptual framework for decentralized green water-infrastructure systems

We present a model for a decentralized green water-infrastructure system (DGWIS) based on a new conceptual framework that optimises the use of captured rainwater, recycled wastewater and renewable energy resources. DGWIS is designed for building-scale localised water supply systems that utilise rainwater and greywater and incorporate advanced small-scale water treatment systems and renewable local energy sources such as solar and wind. Several constraints are considered: (i) available renewable energy; (ii) greywater production rate; (iii) potential captured rainwater; (iv) water demand; (v) water storage volumes required to accommodate greywater, harvested rainwater and separate water/energy supplies from the city and (vi) water treatment capacities. The proposed DGWIS optimisation framework demonstrates proof-of-concept and provides a solid foundation for an innovative paradigm shift towards water and energy sustainability.