A systematic basin-wide approach for locating and assessing volumetric potential of rainwater harvesting sites in the urban area

Abstract

Rainwater harvesting (RWH) has proven to be an efficient method of curtailing water scarcity by substituting it as an alternative water supply which also helps to mitigate the risk of flooding caused due to heavy rainfall. While overcoming the water-related issues, implementation and identifying potential harvesting sites in urban areas on a large scale has always been challenging, necessitating additional research and constraint considerations. The proposed study implements a basin-wide approach and creates a tool using the geographical information system (GIS) to pinpoint site locations to collect rainstorm water. For determining the feasible number of RWH sites, the scenarios were created by considering the minimum basin area. In addition, the volumetric potential of the identified RWH sites was evaluated using the SCS-CN (Soil Conservation Services Curve Number) method by estimating rainfall runoff volume. The proposed methodology is implemented as a case study on the extended area of Jaipur in India, and the analysis shows that all identified locations lie on the outskirts of the study area, ensuring land availability for developing rainwater harvesting structures. As an outcome, the proposed methodology helps to establish the relationship between the basin area, the number of identified RWH sites, and their volumetric potential, creating a benchmark for further conducting similar studies on other areas.