The water table is the underground boundary between the unsaturated zone (where soil pores contain air) and the saturated zone (where pores are filled with groundwater). Water table depth varies by location, season, and precipitation—it may be near the surface in wet areas or hundreds of metres deep in arid regions. High water tables affect construction (requiring dewatering for excavations, waterproofing for basements), agriculture (limiting root depth), and infrastructure (affecting foundation design). Water tables can rise from increased precipitation or fall from drought or excessive groundwater pumping. Development that reduces infiltration can lower water tables by reducing groundwater recharge. Understanding local water table conditions is important for land use planning, building design, and groundwater resource management.