An MINLP-Based Approach for the Design-for-Control of Resilient Water Supply Systems

Abstract

The resilience of a water distribution system is defined as its ability to maintain continuous customer supply, and can be improved by increasing its redundancy in energy and/or connectivity. This can, however, negatively impact other aspects of network performance, such as leakage management. In this article, we consider the design-for-control (DfC) problem of adding new connections (from a predefined set of candidate pipes) to water supply systems to improve their resilience to failure events while minimizing the impact on leakage management under normal operating conditions. We present a mixed-integer nonlinear programming (MINLP) formulation of the problem of optimal link addition for the minimization of average zone pressure (AZP), a surrogate measure of pressure dependent leakage. We implement a method based on spatial branch-and-bound to solve the problem on a case study network from the literature and an operational network part of an urban water system in the U.K. Finally, we validate the improvement in network resilience resulting from the addition of new connections by performing an a posteriori critical link analysis, using the hydraulic resilience measure of reserve capacity.