A groundwater dam is any structure to intercept or obstruct groundwater flow through an aquifer, both natural and artificial, and provide storage for water underground. They are a suitable water supply structure for regions like Pakistan where arid and semi-arid climate conditions are dominated. They can be an alternative solution for conditions when traditional surface dams are not suitable or applicable because of complex geological situation, safety hazards and silting up of dams. However, they cannot be considered for recreation, power generation and as universal method for water supply. By using underground dams for storing water, instead of surface dams, many of the aforesaid problems may be overcome. In addition, besides of their main purpose, providing groundwater storage, underground dams are the most reliable method to prevent saltwater intrusion which is a vital offshore problem. Besides many advantages, there are multiple disadvantages as well; such as inadequate reservoir capacities, more expensive operation costs, and detailed hydrogeological site investigations, aquifer tests before construction. Groundwater dams have been already constructed in several regions around the world, and are not new engineering structures. 

Historically these kinds of structures were constructed in Roman times in Sardinia and old civilizations in Tunisia of Africa. This paper emphasizes on the significance of this type of structures and reviews the general characteristics and historical development of groundwater dams