Distributed Rainwater Harvesting: Novel Approach to Rainwater Harvesting Systems for Single-Family Households

Communal rainwater harvesting (RWH) systems allow a community to collect rainwater from multiple roofs, store and treat it in a central location, and then distribute it back to the community. This paper proposes a novel distributed rainwater harvesting approach to communal rainwater harvesting in which individual households connect the outflow of their RWH systems to a communal storage from which they can retrieve water when their system is not able to meet their water demands. We simulated the performance of the system in two cities, Houston and Jacksonville, for multiple private and communal storage combinations. We measure the performance of the system using the volumetric reliability (VR) metric, which is the ratio of rainwater that the communal system is able to provide to the total water demand. Results showed that the VR gains over a private system of 1%-6% and 1%-4%, can be achieved for up to 10 and 7 connected households, respectively, for Houston and Jacksonville if the emphasis is on VR gain >1.5%. The system achieved higher VR gains for lower total storage capacity in Houston, whereas the system achieved higher VR gains for higher total storage capacities in Jacksonville. This proposed decentralized rainwater harvesting system is attractive in the face of climate change, increases the resilience of water/stormwater infrastructure, and potentially could decrease the likely effects of flooding and property damage from stormwater. (c) 2021 American Society of Civil Engineers.