Abstract:
The occurrence of transient flow in water distribution system creates large pressure forces
and rapid fluid accelerations or deceleration that can cause failure of hydraulic equipment in
a pipe network if adequate transient control measures are not in place. This research dealt
with the study of hydraulic performance of Injibara water supply distribution system project
as a case study. Injibara town is the capital of Banja Woreda and Awi Administrative Zone of
the Amhara National Regional State. Injibara has three kebeles including rural & town kebele
that have total area of 36.19 sq. km, and out of which the Injibara town covers an area of
20.379 sq. km. The water supply distribution system of Injibara town was designed in 2009
by Matt MacDonald consultant, and revised in 2013 by Amhara Design and Supervision
Works Enterprise. The methods used to carry out this research were desk study to evaluate
previous designs, field data collection and data analysis. AFT Impulse model was used for
water hammer analysis, and Water CAD model was used for network simulation. The results
of the AFT Impulse model revealed that there were pressure and velocity change at out let of
pump and inlets of pipe nodes. These changes indicated that the pressure line of three pumps
had water hammer occurrence during pump trip. Hydraulic parameters obtained from the
results of analysis using Water CAD model were pressure, flow rate and velocity of the
distribution system network. There were low pressure values which was less than 5 m water
column during pick hour demand. The low pressure zone villages around hospital & college
areas did not get water at these junctions during pick hour demand. Finally, this research
recommends preventive measures of water hammer by providing surge control devices and
for the low pressure increase diameter of pipe as the first option.
