Abstract:
Safe and adequate delivery of water to a consumption node is an essential function of water
distribution network. However, throughout the world especially in developing countries, the
hydraulic performance of water distribution network is inadequate to transfer available
water to a consumption node. Debre Birhan Town has been experienced frequent and
regular disruption of water because of hydraulic problems related to pressure and velocity
during high consumption period and at night time. This study was conducted in Debre
Birhan Twon and the aim of the study was to model the existing water distribution system for
steady-state and extended period simulation and evaluating hydraulic performance of the
system. For conducting this study, both primary and secondary data were collected and
software such as waterCADV8i, ArcGIS version9.3, EndeNotex2, and Geographic
positioning system Garmin72 (GPS) were used. The study was carried out by selecting pipes
having diameter greater or equal to 80 mm in diameter. The simulated result for both steady
state and extended period simulation showed that the performance of distribution system
related to pressure 24.74% for pressure value (<15m), 74.24% for pressure value (15-60m)
and 0.1% for pressure value (>60m) head and the velocity of pipe flow showed that 76.92%
for velocity (<0.6m/s),18.18% for velocity range (0.6-2m/s) and 4.89% for velocity (>2m/s).
Those problem are resulted from incorrect nodal placement and improper pipe connection
during designing the system and when expanding the network to the newly settlement area.
The total average per capita consumption of the Town in the year 2015 was 15.62 l/p/d
which shows lower performance compared to 20 l/p/d which is set by WHO (2008). The
potential of the projected water demand increment in Debre Birhan Town is greater than the
current supply potential of water sources. The water demand for the Town of Debre Birhan
averagely increases by32.21% every five years up to the year 2030.The performance of the
model was evaluated using model evaluation statistics. The value of the coefficient of
determination (
2 R
) for pressure calibration was 0.98
