<p>The water distribution system (WDS) plays a crucial role in sustaining our society, serving as a vital lifeline. However, the performance of WDS is often compromised by various disturbances. To address this challenge and prevent functionality losses, isolation valves are strategically installed within the WDS. This study introduces a novel approach to isolation valve system (IVS) design, aiming to maximize equity during segment isolation. The proposed method utilizes an objective function centered on equity maximization. To achieve this, the study extends the conventional Gini coefficient by incorporating water demand ratio (reliability) instead of income. This adaptation results in the creation of the Water Lorenz Curve and Water Gini coefficient, which serve as essential metrics for assessing equity in the context of water distribution. An optimization model based on the genetic algorithm (GA) is developed, leveraging the newly introduced metrics. To evaluate the effectiveness of the proposed design approach, a comparison is drawn with the traditional reliability-based design approach. The study applies both models to five benchmark networks, providing insights into their respective performances. The application of these models to the benchmark networks highlights that, while the proposed approach may involve trade-offs in traditional reliability metrics, it excels in various performance indicators. This suggests the potential for a shift from reliability-based designs to equity-based designs without imposing significant cost burdens. Key performance metrics, including reliability, system robustness, resilience, hydraulic geodesic index, and valve installation cost, are employed to comprehensively compare the outcomes of the two design approaches.</p>