Inadequate drainage of surface water, subsurface water, or both can have a significant impact on pavement performance and long-term maintenance costs. This paper discusses how groundwater (subsurface water) that is not adequately controlled can negatively affect the performance of pavement functionality. Forensic methods used to identify the sources of groundwater and measures that are taken to remediate the problem are explained. Forensic investigation revealed that serious consideration in the design of pavements must be given to regional groundwater conditions and the impact possible on both the integrity and the functionality of the pavement and thus on the safety and the comfort of the traveling public.