Abstract:
In recent years, water scarcity in large cities has been notorious, a fact that drives increased
awareness and concern for the preservation of water resources. The optimization of water supply
systems, emerges as an urgent need for a response from the management entities to guarantee the
continuity of supply of this resource, with quality in view of the situation of increased demand
without or with little investments to expand the systems. This research presents a study of
optimization of the distribution network for Xai-Xai City water supply system for the reduction of
losses, through the application of hydraulic modeling tools, the “EPANET” for the construction of
the initial hydraulic model and the “WATERGEMS” for hydraulic optimization of the BAIRRO
13 subsystem network. Using the DARWIN CALIBRATOR - LEAKEGE DETECTION tool from
WATERGEMS it was possible to identify critical network points with water losses occurrence at
different consumption periods, becoming easy to guide the operational teams for timely
intervention or repair. The city under this study has currently about 30.000 customers of which
more than 90% are domestic. The quality of the service tends to deteriorate due to the exponential
increase in the population without, however, being accompanied by the expansion of the service
on one hand, and on the other water losses tend to increase, being currently above 50%. The system
requires financing for investments in rehabilitation, expansion and increased operational efficiency
in order to improve the quality of the service provided. The model developed reveals that the study
area has two different consumption periods, one between 09pm to 04am whose consumptions are
low and the pressures are high and are between 2 to 3 bars and the second period between 04am
to 09pm with high consumptions and low pressures ranging from 0 to 1bar. The physical losses of
water are high in the period of low consumption when the pressure in the network tends to increase.
It was possible to notice that there are many nodes with an indication of a greater potencial of
leakage from 10pm to 04am in the morning. The neighborhood of the Switinine district in the
downtown area revealed to be the one that loses the most water according to the model's simulation
results.
