water table

Water that occupies pores, cavities, cracks and other spaces in the crustal rocks. It includes water precipitated from the atmosphere which has percolated through the soil, water that has risen from deep magmatic sources liberated during igneous activity and fossil water retained in sedimentary rocks since their formation. The presence of groundwater is necessary for virtually all weathering processes to operate. Phreatic water is synonymous with groundwater and is the most important source of any water supply. (Source: WHIT)