ISSN: 2167-0587
Dessalegn Geleta Ebsa
The key sources of water supply are rain water, underground water and surface water. Rooftop rain water harvesting is a technique through which the rain is captured from the roof catchments and. The objective of this study was rooftop rain water harvesting potential for a domestic purpose using samsam water tool. This can be used in dry and wet seasonal situation based up on the roof size and population density, which plays a crucial role in socioeconomic development and keeping the community school welfare. The RTRWH is the most reliable, easiest to access, and suitable source for water supply. This study was carried out from June 2018 to December 2019 based on case study of 3 Jimma University Institute of technology Kito furdisa campus. Since this rainfall data, rooftop catchment, water consumption and water demand data were used as an input. Based on the findings the annual rainfall is 1846 mm. The total roof size of the school is 888.32 m2 and almost the entire age of the building is ranges between 5 years-15 years which has been constructed by galvanized iron in which its run off coefficient is estimated to 90%. The collected data have been analyzed using different tools including samsam water RWH model, and SPSS statistics version 22. As a result, the volume of harvested rain water was 12,826 m3/ yr. which cover all non-potable water needs for 14,458 of school population. The total yearly water requirement for a working day (182 days) and working days plus none working days (365 day) of the school is 18,606.72 m3/yr and 26,759.47 m3/yr. respectively. The reliability of harvested rainwater from the rooftop for the community school can be meeting about 63.4 % of water scarcity reduced by feeding for (365 days). Whereas the reliability of rainwater harvested potential is 82% of water demand can be meeting by considering the schedule of working days (9 months). The averagely reliable for the study area is great than 72.6% of water demand.