Analysis of a rainwater harvesting system for domestic water supply in Zhoushan, China

The domestic rainwater harvesting system (DRHS) is an important freshwater source for Zhoushan, China to meet water demands. A computer model has been generated to analyze the performance of the DRHS with different ratios of D/(AR) (water demand/average annual collected runoff) and S/(AR) (storage capacity/average annual collected runoff). The performance of the DRHS was analyzed by means of the model simulation, which is described by its water shortage rate (WSR) and water loss rate (WLR). Using the data, a set of dimensionless design calculation chart is introduced. When the water demand and requirement of the design are known, the established chart can be used to easily determine the storage capacity and catchment (roof and other surface) area required to achieve a desired performance level.