Leakage in water distribution networks precipitates both water wastage and the ingress of pollutants. The localization of leaks, a formidable challenge within water demand management, has spurred an examination of hydraulic simulation-based methodologies as a more economically feasible and time-efficient alternative to conventional methods. This paper introduces a framework for precisely determining the location of leaks within a water distribution network, leveraging the Grasshopper Optimization Algorithm. The approach meticulously compares simulated data with pressure field information. Acknowledging the intrinsic uncertainties pertaining to hydraulic model parameters-such as elevations, nodal base demand, and pipe roughness coefficients in real-world water distribution networks-the developed method incorporates perturbation analysis for judicious parameter selection. Monte Carlo simulation is then employed to apply these parameters in the simulation process systematically. The efficacy of the method is demonstrated by applying it to benchmark water distribution networks (specifically, Poulakis and Balerma) under various leakage scenarios, achieving accuracy levels of up to 99%. Introducing uncertainty into the simulation process results in a maximum 20% reduction in method accuracy. Real-world implementation successfully and accurately localizes leakage, affirming the practical applicability of the proposed method for water utilities.