A WATER SUPPLY SYSTEM STUDY AND ASSOCIATEDGAPS ON SANITATION OF THE DAYE TOWN, SIDAMA REGIONAL STATE, ETHIOPIA

Abstract

Safe and adequate delivery of water to a consumption node is an essential function of a water distribution network. Daye Town has experienced frequent and regular disruption of water because of hydraulic problems related to pressure and velocity during high consumption period and at night-time. The main aim of this study was to model the existing water distribution system for steady-state and evaluate hydraulic performance of the system and sanitation condition of the town. For conducting this study, both primary and secondary data were collected and tools such as WaterGEMS and SPSSwere used. Questionnaire was used for the sanitation assessment for the selected sample households. Pressure gauge was used and the pressure on the selected points on the water supply system measured and then validated with the result from hydraulic modeling analysis. The existing water sources studied, and the population of the town analyzed for the present and the forecasted, 20 years. Accordingly, the total average per capita consumption of the Town in the year 2022was 9.21 l/c/d which showed lower performance compared to 50 l/c/d which is set by GTP-II of the country for category 4 town and 34,714m 3 /year (25.03%) of water is considered to be non-revenue (NRW) and the apparent losses and real losses of the town was 0.9% and 26.44% respectively. There is high gap between demand and supply in the town because the current (2022) and the future (2041) maximum day water demand of the town was 1741.04m 3 /day and 4,581.81 m 3 /day respectively and the current (2022) water production of the town was only 511.2 m 3 /day which only satisfies 44% of the current demand (2022) and 17% of the future demand in year 2041. Therefore, securing additional water supplies becomes an essential issue to meet the current and future water demand of the town. The simulated result showed that 41.35% for pressure value (<10m) and 58.65% for pressure value with recommended value (11-70m) base xii consumption and the velocity of pipe flow showed that 51.3% (<0.6m/s) and 48.7% the range of (0.6-2m/s). The performance of the model was evaluated using model evaluation statistics. The value of the coefficient of determination (R2 ) for pressure calibration was 0.96. Moreover, potential causes of water losses in the town water supply system were assessed, water losses reduction strategies are designed, and the system pressure and velocity are adjusted. Finally, sanitation associated gapsmainly the latrine in household and selected institutions and excreta disposal and transportation was assessed. Percent of households with access to sanitation facility and percent of households with year-round access to improved water system for sanitation was27.52% and 15.5% respectively