An assessment of technical feasibility in the implementation of rooftop rainwater harvesting system in urban residential areas of Pakistan

This research assesses and discusses the technical feasibility of rooftop rainwater harvesting system (RWHS) for urban residential areas of Rawalpindi; the fourth largest city of Pakistan. Rainfall datasets covering average rainfall for Rawalpindi are analysed on the basis of previous yearly estimations of average rainfall and number of precipitation days. Furthermore, it is estimated what the average monthly rainfall is from different sources. Moreover, rainwater that can be captured is analysed through the selection of catchment areas, i.e., house 'rooftops'. In addition, per capita water demand is analysed on the basis of previous findings and considered to generate the average per capita non-potable water demand in the study area. Also, the practicalities of rooftop RWHS are examined in terms of consecutive dry days and storage capacity. These estimations and analyses are used to perform the technical feasibility