Presented by IWMI’s Yvan Altchenko at the 26th General Assembly of the International Union of Geodesy and Geophysics (IUGG), held in Prague, on June 25, 2015. Session - Societal Relevance of Groundwater: Ever Increasing Demands on a Limited Resource

1. Transboundary Aquifer Mapping and Management in Africa:
An Ongoing Process
Yvan Altchenko & Karen G. Villholth
PhotobyK.Villholth/IWMI

2. Groundwater resource in Africa
• Total groundwater storage in Africa
approx. 0.66 million km3 (0.36 - 1.75
million km3)
• The estimated volume is more than
100 times estimates of annual
renewable surface freshwater
• Not all is available for abstraction (MacDonald et al., 2012)
• 75 % of the African population dependant on groundwater for basic water supply (UNECA
et al., 2000)
• Groundwater demands are set to increase in the future with:
• Population increase
• Climate change
• Need to combat growing food insecurity

3. • Water and land use, and groundwater (GW) development in one state may affect GW
resources in another, and GW impacts may not be obvious without joint monitoring
• Surface Water (SW) issues involve, or even have root in, GW related activities and impacts
• Many transboundary terrestrial and aquatic ecosystems are GW-dependent and cannot be
properly managed without knowledge on the GW resources
• Equitable, informed, and mutually agreed development of GW and land use can prevent
tension
• Equitable and informed GW development and management has a lot to do with achieving
MDGs/SDGs: poverty alleviation, food security, climate change adaptation, and drought
mitigation
Why focus on groundwater management in a transboundary sense?

4. What is a Transboundary Aquifer (TBA)?
Where to find a TBA?
(UNESCO/ISARM, 2001)
DEFINITION
A transboundary aquifer or a transboundary aquifer system (TBA) is defined as “an aquifer or aquifer
system, parts of which are situated in different States” (UN International Law Commission - UNILC)
BUT
in practical identification and verification of a TBA, the spatial delimitation, hydrogeological similarity,
recharge and discharge mechanisms and zones, and significant hydraulic connectivity between the
national compartments of the TBA are important and should be established and agreed upon
between aquifer-sharing states

5. Evolution of the number of TBAs in Africa
WHYMAP(2006) IGRAC (2009) IGRAC (2012)
AFRICAN REGION
UNESCO
2004
WHYMAP
2006
IGRAC
2009
IGRAC
2012
North Africa 6 6 7 9
Western and Central Africa
(except countries in SADC)
9 9 9 22
Eastern Africa
(except countries in SADC)
5 5 5 6
Southern Africa
(SADC countries)
18 20 20 34
TOTAL 38 40 41 71

6. Evolution of the number of TBAs in Africa
IGRAC (2015)IGRAC (2014)IWMI (2013)
AFRICAN REGION
UNESCO
2004
WHYMAP
2006
IGRAC
2009
IGRAC
2012
IWMI
2013
IGRAC
2014
IGRAC
2015
North Africa 6 6 7 9 15 15 12
Western and Central Africa
(except countries in SADC)
9 9 9 22 22 26 18
Eastern Africa
(except countries in SADC)
5 5 5 6 8 8 8
Southern Africa
(SADC countries)
18 20 20 34 35 34 34
TOTAL 38 40 41 71 80 83 72

7. A new nomenclature proposed
based on 3 geographic regions
zones

8.  80 transboundary aquifers
(83 transboundary aquifers – IGRAC 2014)
(72 transboundary aquifers – IGRAC 2015)
 42 % of area of Africa
 30 % of African population
 63 international river/lake basins
 21 international water basin organisations
The TBAs map of Africa

9.  72 transboundary aquifers
 Some TBAs identified in Central Africa and
North Africa have been removed
 Some identified TBAs have been joined into
one TBA in Northern Africa, Western and
Central Africa, and Southern Africa
The IGRAC 2015 TBAs map

10. TBA Information table

11. TBAs management
 Transboundary water resources management has been totally dominated by a surface water
focus, practically ignoring the interconnections with surface water
 Data on TBAs reside in national institutions, transboundary River/Lake Basin Organisations
(R/LBOs) and other international organisations, e.g. IGRAC
 Two options to adopt groundwater into international agreements:
• The 1997 United Nations WaterCourses Convention (UNWCC), which defines GW as a
physical extension of a surface water body within the watercourse spatial domain. The
treaty has been ratified by 35 states and entered into force since 17 August 2014.
BUT groundwater boundaries don’t necessary match with river basin boundary
• The 19 drafts articles on the Law of Transboundary Aquifers presented in 2008
BUT still not adopted by the UN General Assembly, which however promotes bilateral
or regional agreements between the countries in the interim, e.g. Guarani Aquifer
(South America)
 African Ministers’ Council on Water (AMCOW) promotes TBAs management by R/LBOs

12. International basins
TBAs
TBAs management by R/LBOs ?
• Argument for:
Their present integral role as custodians for
shared river and lake basin resources
• Counterargument:
• Poor human capacity, financing and
authority
• The geographical location of the TBAs
doesn’t necessary match with the spatial
mandate of the R/LBOs

13. • 3 groundwater explicit agreements:
• Nubian Sandstone aquifer system (AFNE12) from 2000
• North Western Sahara aquifer system (AFNE16) from 2002
• Irhazer – Iullemeden (AFWC15) from 2009
• SADC is taking a frontrunner position in TBAs management, next to Northern Arica:
• Protocol on Shared Watercourses revised in 2000 and hinged on the UNWCC
• Regional Strategic Action Plan for integrated water resources management explicitly
addressing TBAs management
• Work in progress on two TBAs:
• AF5 (Stampriet)
• AF7 (Ramotswa)
Current TBAs management in Africa

14. • TBAs identification and delineation is an on-going process
• TBAs management is expected to raise the profile of neglected local/national GW resources
management, especially in low development countries
• TBAs management can reduce future conflicts linked with GW development
• BUT there is a need to:
• understand flow processes and interactions with surface water
• develop collaboration and knowledge sharing between the riparian countries
• reformulate and adapt the legal basis of R/LBOs to include explicit mentioning of GW
(not as a new and separate domain)
• design flexible and hybrid institutional models built on the present customary approach
of making the R/LBOs responsible
Conclusions

15. References
• Altchenko Y. and Villholth K.G. (2013) Transboundary aquifer mapping and management in Africa: a
harmonised approach. Hydrogeol. J., doi: 10.1007/s10040-013-1002-3
• MacDonald A, Bonsor H, Dochartaigh B, Taylor R (2012) Quantitative maps of groundwater resources
in Africa. Environ. Res. Lett. 7, doi:10.1088/1748-9326/7/2/024009
• United Nations Economic Commission for Africa (UNECA), African Union (AU), and African
Development Bank (AfDB) (2000) The Africa water vision for 2025: equitable and sustainable use of
water for socioeconomic development, 28 pp.
• IGRAC http://www.un-igrac.org

16. PhotobyX.Cai/IWMI
PhotobyK.Villholth/IWMI
PhotobyK.Villholth/IWMI
PhotobyY.Altchenko/IWMI
http://www.slideshare.net/IWMI_media
Thank You
Merci