Speculations on the sources of water inflow in the subgrade sand were made by the various parties, and the origin of the retained water would be crucial in determining an appropriate long-term dewatering scheme. Technical data indicated that overflowing from secondary canals and water infiltration through the grassing area adjacent to the airfield pavements were the most possible causes. Overflowing could be controlled with proper water level control management, but the water infiltration issue cannot be resolved easily without major modifications to the grassing zone and surface runoff from the pavement in taxiway areas.