Accurate determination of flow direction in water distribution networks is a fundamental prerequisite for hydraulic modeling, leakage detection, valve isolation, and network maintenance. While ArcGIS Utility Network Analyst provides robust tools for tree-like (branched) networks, it fundamentally fails to assign determinate flow direction in looped configurations due to the absence of inherent downstream topology. This study addresses this critical gap by developing a novel custom extension, the "Individual Flow Direction Tool," which integrates high-resolution LiDAR-derived digital elevation models with geometric network intelligence to assign flow direction on a per-hydro-edge basis. The research methodology comprises four integrated phases. First, a comprehensive geodatabase was designed incorporating 12 feature classes (pipelines, valves, fittings, hydrants, reservoirs, meter-boxes) with predefined subtypes, attribute domains, and connectivity rules. Second, a 1m-resolution DEM and subsequent 3D surface model were generated from airborne LiDAR data (decimeter accuracy). Third, Z-values were extracted for all junction endpoints using the "Extract Values to Points" tool. Fourth, the IFD Tool-developed as a custom ArcGIS add-in-was programmed to evaluate each edge individually based on the comparative Z-values of its two terminal junctions, iteratively propagating flow determination through complex loop systems. The tool was validated against field-verified flow data from Syarikat Air Johor Holdings for 14 interconnected loops comprising 3.7 km of PVC pipelines (D=150mm, C=150) in Taman Mutiara Rini, Malaysia. The IFD Tool successfully assigned flow direction to 100% of network edges. Comparative analysis revealed 79% agreement (1,428 out of 1,807 edges) between LiDAR-based flow assignments and SAJH field data, with 21% disagreement primarily concentrated within loop interiors rather than source-sink trunks. Hardy-Cross verification confirmed hydraulic balance in all disagreed edges, demonstrating that the Hardy-Cross method can yield multiple valid flow solutions for a given looped network. Consequently, the 21% disagreement does not indicate a methodological flaw; rather, it reflects the existence of multiple hydraulically balanced flow regimes. The SAJH field data captures the specific operational state influenced by undocumented interventions (e.g., booster pumps, partially closed valves), while the IFD Tool provides the topographically natural baseline. This research presents the first documented ArcGIS extension specifically designed for looped-network flow assignment using topographic intelligence. The IFD Tool transforms WDN management by enabling scientific, reproducible flow determination independent of subjective engineering judgment. Based on this specific case study (flat terrain, uniform PVC pipes), the methodology is estimated to reduce utility expenditure on flow direction field verification by 70-80%. However, further validation across diverse topographic conditions and pipe materials is required to generalize this estimate.