Abstract:
Water is one of the prime requirements for life, and the Water supply systems are one of the most
important and expensive core public infrastructures. In urban area of Ethiopia, water demand is
increasing day to day due to urbanization. During operations of water supply systems in many
towns of the Country, the common problems are pressure drops, Leakages, contamination and
lack of a simple tool to accurately predict low and high pressure zones areas. Hence, the aim of
this study is to assess the performance of the water supply system in terms of pressure and
velocity variation using Water GEMS V8i software and to evaluate the amount of annual water
loss in the system. Sample kebeles and sample population were selected to distribute
questionnaires in order to collect information about current daily water supply amount and the
level of customer satisfaction with current supply. And the distribution network data like; pipes
data, junctions’ data, reservoirs data and other appurtenance elements of the network data were
collected from Jimma Town Water Supply, Sanitation Service Enterprise(JTWSSSE) office.
Based on the result of the study, the current average water supply coverage is found to be low
(10 l/c/ dy).In Jimma town, the annual average water loss for the consecutive eleven years (2008
– 2018) is founded to be 39.14 % out of the total yearly production. This amount is 13,796,488
m
3
out of the total water production of 35,312,888 m3
in the last 11 years. This annual percent
loss of water is more than the tolerable percent loss value of water for developing countries.The
pressure and velocity distribution along the current distribution system is also found to be far
from the recommended range. Water GEMS software was used to optimize the system by
modifying and re-arranging the network elements for further improvement towards the pressure
and velocity distribution and demand satisfaction. The result shows that, the system performance
was increased ie. The number of junctions and pipes that have pressure and velocity in the
recommended range was increased. Therefore, JWSSSE should modify and re arrange to
improve the system according to the recommended modification in this study to maintain the
system safe and customer satisfaction.
