Transboundary Aquifers of the World 2012

Transboundary Aquifers of the World 2012

At this year's World Water Forum 6, held in Marseille, IGRAC presented a new update of the Transboundary Aquifers of the World Map highlighting the work and efforts of the past three years in identifying and delineating the world's transboundary groundwater resources. 

Key departures from the TBA Map 2009:

  • For EU countries (plus Switzerland and Norway) this global map now displays transboundary Groundwater Bodies (GWB), rather than transboundary aquifers, as adopted by the Water Framework Directive (WFD). Within this framework, EU Member States are obliged to delineate groundwater bodies (managerial units) to identify the risk of failing to achieve ‘good status' by 2015. In many cases, aquifers are subdivided into groundwater bodies while occasionally groundwater bodies may contain multiple aquifers.
  • Through combined efforts of many organisations, stakeholders and governments around the world we are today aware of 445 transboundary aquifers and GWBs (380 in 2009).
  • Since being first included in this inventory many TBAs received further attention, leading to precise border delineations.

Full detail on the methodology creating this map as well as definitions and additional information such as on the legend are given on the back side of the map. Further the back includes the ‘Draft Articles on the Law of Transboundary Aquifers', to which IGRAC as member of the ISARM core group contributed and a commentary by water law expert and senior UNESCO-IHP consultant Raya Marina Stephan.


We are always keen to hear your opinion about our newly updated map. As the knowledge on transboundary aquifers is still limited and mapping our shared groundwater resources a continuous process please let us know about newly identified and/or delineated aquifers/GWBs in your region so that we can include them in the future. Please provide comments and suggestions to

Paper Copies

If you wish to receive a hardcopy of our 2012 map, please email us at (please include your postal address).