**5. Conclusions**

Hydraulic modeling of WDNs is an important step towards the development of efficient water managemen<sup>t</sup> practices and strategies, with the aim of reducing water losses and the associated financial cost and environmental footprint. In the current work, we developed an easily applicable methodology for the effective modeling of WDNs that maintains a sufficient level of estimation accuracy with minimal computational load, using a sensitivity analysis to determine the appropriate nodal density, in order to effectively describe both the topographic variability as well as the original connectivity of the network. Additionally, the water requirement at each node in the network was established by combining two factors: one being driven by demand and the other by pressure, resulting in more accurate depictions of the operational pressures.

The developed hydraulic models allowed us to implement and test a variety of methodologies regarding water loss estimations (see [7]), the identification of pressure control failures and the release of notifications (see [5]), as well as the optimal partitioning of WDNs into PMAs, without undermining the overall hydraulic resilience of the network (see [9]). The developed approaches can significantly reduce the volume of lost water (30% on average in each PMA), which corresponds to approximately €300,000 in annual savings, based on the balance sheet of the fiscal year 2019 (see [10]).

**Author Contributions:** Conceptualization, methodological formulation, and interpretation: A.V.S. and A.L.; data preprocessing, formal analysis, verification, visualization, and writing—original draft preparation: A.V.S.; writing—review and editing: A.P., N.T.F. and A.L.; funding acquisition, project administration, and supervision: A.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** The research project was supported by the Hellenic Foundation for Research and Innovation (H.F.R.I.) under the "1st Call for H.F.R.I. Research Projects to support Faculty Members & Researchers and the procurement of high-cost research equipment grant" (Project Number: 1162).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** The data used are protected under a nondisclosure agreement. Acquisition requests should be addressed to DEYAP (https://www.deyap.gr, accessed on 1 November 2022).

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