<p>The rapid increase in domestic and agricultural water demand in the Municipality of Gjilan has intensified the need for new, sustainable water resources. This study aims to identify the most suitable location for the construction of an accumulation dam in the “C.Z. Pograxhë” catchment by applying a GIS-based multi-criteria decision analysis framework grounded in the Analytic Hierarchy Process (AHP). Eight spatial and non-spatial criteria were considered: terrain slope, geology, catchment size, precipitation, distance from roads, distance from settlements and protected areas, distance from rivers, and land ownership. The criteria were weighted through pairwise comparisons supported by an expert panel, and integrated in a weighted overlay analysis to produce a suitability map for dam site selection. The results indicate that a substantial proportion of the study area exhibits moderate to high suitability for dam construction, with the most suitable zone located along the Llapushnik River corridor. Two design scenarios were evaluated, corresponding to planned dam heights of 32 m and 42 m. The estimated total storage capacities are 1.69 × 10⁶m³ and 3.29 × 10⁶m³, respectively, which would satisfy projected municipal water supply requirements for approximately 10 and 20 years. A validation and sensitivity analysis demonstrates that the spatial pattern of highly suitable areas is robust to reasonable variations (± 20%) in the factor weights, and that locations identified as highly suitable are consistent with expert judgement and existing planning documents. The study confirms the effectiveness of integrating AHP with GIS-based cartographic modelling for dam site selection in data-limited environments. Beyond providing a concrete candidate site for an accumulation dam in the “C.Z. Pograxhë” catchment, the proposed framework can support planners, water utilities, and policymakers in screening and prioritizing alternative locations for new water resources at municipal and regional scales. </p>