Abstract:
Currently Butaji ra town is inside the zone of critical water shortage . Besides the town
water supply enterpri se is not in a position to cover the capital and operati on and
maintenance costs. Accordingly this paper has set out to maximize the total revenue
collected from customers and quantifies the unsatisfied demand so that investment i n
new water supply scheme developments can be planned and scaled . The various
methods employed includes review of existing system design , topographic survey data
was collected and search for opt i mal diameter of pump i ng mains pipe lines is done , The
present water supply deficit is calculated and the future water demand is forecasted by
use of water use forecasting model, Hydraulic ana l ysis of the distribution system has
been done using steady-state water distribution models, Linear programming technique
concept has been used in the formulation of optimization problem , and several
stakeholder consultations have been carried out with the major stakeholders .
According to the results of water demand assessment the town has got 59%, 36% ,
22%, 17% cover age in the current year, 2015 , 2020 and 2025 respectively . The annual
production loss amounts to 25% . Based on the study of water sources ground water is
more feasible currently. It is found that 1 OOmm, 11 Omm, and 150mm are the optimum
pumping main sizes. The present minimum tariff rate in order to cover operation and
maintenance cost is found to be 2 . 63birr/m3 , 2 . 92birr/m3 , 3 . 80birr/m3 and 4 . 36birr/m3
for the four consumption categories 1-5m
3
/month , 6-1 Om
3
/month, 11-30m
3
/month , and
>30m
3
/month respectively . The tariff rate structure should be revised period i cally based
on OM costs and the model here can be used to generate the tariff. An interactive
FORTRAN program has also been developed which computes the total service charge .
From th i s study it is concluded that currentl y the water that i s produced from all the
existing sources of supply covers only 60% . From the current supply sources the water
supply enterprise losses 233 . 28m3/day . The total revenue collected from the customers
could not cover the operation and maintenance costs of the water supply system. The
study shows that optimization modeling is a powerful approach for supporting and
enhancing a sound decision-mak i ng process in water industry .
