**4. Conclusions**

Although its use is generally applied to CWS, the setting curve is a useful tool for evaluating and improving systems with intermittent supply.

The approach using theoretical maximum flow enables network capacity to be given its true quantitative dimension. This is necessary for decision-making in the assessment, management, maintenance, operation, and design of a continuous or intermittent supply drinking water network. Specifically, in this paper, this approach enables us to evaluate a system with intermittent supply, track its evolution from its CWS origin (first part of the study) to the current IWS, and propose solutions to recover CWS (second part of the study). Thus, this study contributes to improve intermittent supply systems, which remains one of the main challenges related to water and health in developing countries.

In the first part, we can see how poorly planned expansion processes can systematically reduce network capacity. This reduction initially brought low pressure, flow failure in unfavorable areas, and user complaints. The situation was perceived as water scarcity rather than reduced network capacity. As a result, it was decided to opt for intermittent supply. Further expansion actions consolidated this approach.

It is important to consider that the rational extension of the network not only involves laying additional pipelines that reach the point of demand, but that this process should be accompanied by the reinforcement, rehabilitation, or replacement of the network water mains.

A process of expanding network capacity, as part of the transition from IWS to CWS with poor funding, is difficult to implement. Consequently, gradually prioritizing pipe replacements, based on achieving the greatest impact on the quality of service at the lowest cost, is a very useful criterion. The characteristics of the method allow us to reach a more efficient process in small networks than in large ones.

**Acknowledgments:** The authors are grateful to SeLA (water company in Oruro (Bolivia)) for providing information. The use of English has been revised with the help of John Rawlins.

**Author Contributions:** Ilaya-Ayza, A.E., Izquierdo, J., and Pérez-García, R. conceived and designed the study. Ilaya-Ayza, A.E. wrote the manuscript. All authors read and approved the final version of the manuscript.

**Conflicts of Interest:** The authors declare no conflict of interest.
