Abstract:
Water distribution system(WDS) are critical infrastructure components that supply
drinking water over area of the community. Water distribution system(WDS) are designed
to provide consumers with a minimum acceptable level of supply in terms of pressure,
velocity, availability and water quality at all times under a range of operating conditions.
Hydraulic performance is the main criterion to evaluate the efficiency of the water
distribution system. The general objective of this study focused on the hydraulic
performance evaluation and modelling of water supply distribution system of Karewo town
and the specific objectives are to evaluate the existing water supply capacity and demand,
to simulate the hydraulic performance of WSDS, to identify the physico-chemical drinking
water quality of the town and to evaluate the water supply coverage of karewo town. All
relevant primary data collected from the project site and the secondary data has been
collected from Dawro Zone water, mine and energy department, Zaba Gazo woreda water,
mine and energy office and Karewo town municipal and water utility office. The collected
data has been simulated on the combination of WaterGEMSV8i, ArcGIS, Google mapper
and AutoCAD software’s. The water supply and demand of the town was un balanced
because the water supply of the town annually is 134,028m3
and annual demand is
450,176.4m
3
. The hydraulic performance of water supply distribution system was
simulated by waterGEMSV8i and the result indicates 5.12% of junction pressures below
normal minimum standard 15m and 34.61% is above exceptional maximum standard 70m
and 60% is on the range allowable limit. The velocity distribution in the pipe lines result
are larger portion pipes has low velocities below 0.6m/s and small portions of the pipe
lines has high velocities above the permissible velocity of 2m/s. The laboratory test result
of physico-chemical water quality parameters is under the acceptable WHO and Ethiopian
standard and dissolved ammonia(NH3) is above or greater the WHO and Ethiopian
guidelines. The water supply coverage of the town in terms of per-capital consumption and
level connection was 29.8% and 26.6% respectively.
