Jacob Monroe presented new and emerging research at the Small Water and Wastewater Systems Conference in Perth, Australia in December 2019. Jacob’s presentation describes a smart water grid that allows households to buy rainwater from their neighbors.
Urban water management must address challenges with water shortages across the globe, due to limited resources, development of urban demands, and climate change. Novel water markets and water supply paradigms have emerged, including fit-for-purpose water reuse that delivers water treated to certain quality standards for appropriate end uses and on-site rainwater harvesting to meet non-potable household demands. In this study, we propose a peer-to-peer non-potable water market that allows households to capture, use, sell, and buy rainwater within a network of water users. This framework proposes that a peer-to-peer non-potable water market can be enabled by existing and emerging technologies, as follows. First, households need cisterns or tanks to collect and store rainwater from rooftop runoff. Second, a community pipe network is needed to serve as the backbone for the water trading network by receiving water from rainwater harvesting tanks and distributing water at households. The dual reticulation system should be dedicated to circulating non-potable water and augmented by a base flow of reclaimed water. Third, Advanced Metering Infrastructure (AMI) is needed to sense and record water contributed to and withdrawn from the water network at each household on sub-hourly time steps, and, fourth, blockchain technologies will be needed to create a ledger to record transactions between peers. This manuscript describes the water infrastructure components that enable a peer-to-peer nonpotable water market and explores the hydraulic feasibility of a micro-trading system. An allpipe hydraulic model is constructed for a hypothetical community to simulate the storage dynamics in household-level tanks, demands exerted for non-potable uses at households, and hydraulics in the dual reticulation network. Simulations explore how micro-trading may affect nodal pressures, flows in the network, and energy consumption. Results explore the tradeoffs between energy and water savings.