The Groundwater Resources Governance in Transboundary Aquifers (GGRETA) Project addresses issues related to Transboundary Aquifers and responds to the pressing need of increasing the knowledge on their physical and socioeconomics characteristics. It is an integral component of the UNESCO’s International Shared Aquifer Resource Management (ISARM) Initiative and the Transboundary Waters Assessment Programme (TWAP).

In-depth assessments have been conducted in three selected case studies:

• The Esquipulas-Ocotepeque-Citalá (Trifinio) Aquifer in El Salvador, Guatemala and Honduras.
• The Stampriet-Kalahari/Karoo Aquifer in Namibia, Botswana and South Africa.
• The Pretashkent Aquifer in Kazakhstan and Uzbekistan.

Stampriet-Kalahari/Karoo Aquifer

Stampriet-Kalahari/Karoo Aquifer study area

The Stampriet Transboundary Aquifer System (STAS) covers a large arid region stretching from Central Namibia into Western Botswana and South Africa’s Northern Cape Province. It contains two confined sandstone aquifers and the overlying unconfined Kalahari aquifer units. The delineation of the STAS area follows the outer boundary of the so-called Ecca Group of geological formations within the catchments of the Auob and Nossob rivers. The STAS is a very large transboundary aquifer system, receiving insignificant recharge, in a dry region without permanent surface water.