Use of Demand-Driven Models for Reliability Assessment of Distribution Networks in Developing Countries

Generally improved access to computers and affordable software has promoted regular use of hydraulic modelling for design of water distribution networks worldwide. The bottom line to conduct such a design adequately has therefore been shifted to the quality of the model input data, which are often unreliable and/or incomplete for many networks in developing- and countries in transition. The paper demonstrates two possible approaches from the literature that can be used to assess the network reliability under the constraints caused by scarce information about the system, and in the absence of highly sophisticated network modelling software. These have been applied to the case networks from Indonesia and South Korea, respectively and the results were compared. In the first case, the EPANET hydraulic model has been developed together with a simple spreadsheet application to calculate the reliability and availability coefficients of the networks in two districts at the outskirts of the capital Jakarta. In the second study, the EPANET programme has been used to build a semi-pressure driven model of a secondary town, to test the sensitivity of the reliability- and availability factors for various ‘what-if' scenarios. The results show that despite some shortcomings, both methods offer a fair first indication about the network reliability and as such can be used in practice without of much additional coding or advanced modelling required. A few suggestions pointing further improvement have been listed in the conclusions.