Rainwater harvesting in University Buildings: Potable Water Savings Potential and Investment Feasibility Analysis

Abstract The application of the RWH system in universities not only helps to reduce financial expenditure but also provides a good opportunity to educate students about sustainable water management. This study uses daily rainfall data of three different climate regimes (dry, average, and wet years) to evaluate the potable water saving and economic efficiency of the proposed RWH system in a university campus in Guangzhou, China. The economic analysis shows that, except for two residential buildings, the installation of the RWH system in the four educational buildings is generally economically viable, with benefit-cost ratios ranging from nearly 1.0 to 2.01 and positive net present values of 5245 to 74963 CNY under normal and wet years. It is also observed that the RWH system in the academic buildings is more economically feasible than the student apartments, and the multi-story apartment building is more attractive in terms of financial returns than the high-rise building. The performance of the data for different buildings helps us to understand the range of water-saving efficiency and economic feasibility of the RWH system, and information on which type of building is appropriate to install an RWH system, which will be of great benefit to sustainable campus construction.