Optimal Sizing of Rooftop Rainwater Harvesting Tanks for Sustainable Domestic Water Use in the West Bank, Palestine

In highly water-poor areas, rooftop rainwater harvesting (RRWH) can be used for a self-sustaining and self-reliant domestic water supply. The designing of an optimal RRWH storage tank is key parameter to implement reliable system. this study, the size tanks in different West Bank governorates was estimated based on monthly (all governorates) daily (i.e., Nablus) inflow outflow (domestic demand, DWD) data. estimation RRWH, five areas varying between 100 m2 300 were selected. Moreover, reliability adopting system tested. Two-time series scenarios assumed: Scenario 1, S1 (12 months, annual) scenario 2, S2 (8 rainy). As result, curves preliminary obtained. Results show that required (annual) more than (rainy) one. fulfill DWD average area 150 m2, family members 4.8, 90 L per capita day (L/c/d) varies (75 m3 136 m3) (24 84 governorates. Further, it found ranges 20 (in Jericho) 75 Salfit 51 Jerusalem) scenarios, respectively. Finally, results implementation 4.8 all except Jericho. Whereas, doesn’t exceed 19% two scenarios. However, reduction DWDv affecting systems Jericho (the least rainfall governorate). For instance, 3.2 m3/month (25% Bank) will increase at 51% 76% S2,