Groundwater or subsurface water refers to all water below the surface of the ground including that in the saturated zone and in deep aquifers. Subsurface water has been a readily available source for humans over centuries and has been particularly associated with developing nations. This source has in the past been ill managed and has caused water quality issues in many communities around the world. In recent times, serious drought conditions have affected the vast Australian Island continent and government authorities have considered pumping large amounts of groundwater for drinking use in many states; that is, pumping groundwater for inclusion in the direct supply networks. This paper explores the effects of longer term pumping; in particular various issues related to the excessive groundwater pumping. The review shows that majority of the affected areas are coastal lowlands where most of the world's population reside. Long term effects that warrant serious attention are saltwater intrusion, aquifer overdraft, groundwater depletion, land subsidence. Each of these has had severe consequences for the areas concerned and indeed some more the others. However, in the past, the most reported has been saltwater intrusion at the expense of the others.