DEVELOPMENT OFA MODEL FOR OPTIMIZATON OF WATER SUPPLY SYSTEM COST AND SUPPLY PROBLEMS WITH A CASE STUDY FOR HOSSANA TOWN

Abstract

The provision of safe and adequate water supply has a direct impact on existing socio-economic activities and health of a community. The existing water supply schemes which are under operation should satisfy the ever increasing demand at optimum level , hence planning of new water supply utilities is a must before the design period of existing sources of supply is over and they are rendered inadequate . The objective of this study is to quantify the supply deficit and unaccounted for water so that! additional investments in new water supply utilities can be planned , scaled and sequenced to set a solution for the acute water supply shortage , and to maximize the total revenue collected from the customers so that the total revenue collected from the customers could cover the recurrent cost of the system. In this study Hossana Town, water supply system is taken as a case study. According to the results of water demand assessment the town has got 41 . 8% water supply coverage and 25 . 2 % of the annual production is lost as physical and non - physical losses . In any water supply scheme a consumer should pay at least the full cost of providing him with water, other wise for sustainability of the service the system should be subsidized . In this study linear programming technique concept has been used to maximize the revenue as a result the total revenue collected from customers could cover the recurrent cost of the system. According to the result of this study, the present minimum tariff rate in order to cover the OM cost is found to be 3.22 Birr/m 3 and the tariff rate structure should be revised periodically based on OM costs and the model here in can be used to generate the tariff. An interactive FORTRAN program has also been developed which computes the total water service charge