The understanding, exploitation and management of groundwater in the Sahelian regions are major
social, political and environmental challenges with respect to the achievement of the Sustainable
Development Goals, especially the water-related SDG 6, whose ambitions are still far from being achieved in
this particularly arid part of the world. Due to both the aridity of the climate, which limits the presence of
surface water and the recharge of aquifers, and to the physical and cognitive barriers to accessing
groundwater that is “naturally hidden”, the hydrogeology of the Sahel is a particularly vast field of
investigation for national and international hydrogeologists. The stakes and methodological challenges are
considerable for the discipline. However, in the Sahelian countries, hydrogeology isstill a discipline thatseeks
professional and institutional recognition. As part of the Sahel Groundwater Initiative, the World Bank aims
to strengthen Sahelian hydrogeology. In this context, a socio-anthropological research on the "world" of
Sahelian hydrogeology was carried out as part of a consultancy involving IRD and 2iE. Bringing together about
fifteen experts in hydrogeology, from six Sahelian countries (Burkina Faso, Chad, Mali, Mauritania, Niger,
Senegal) and from France, this consultancy allowed to gather knowledge and opinions concerning Sahelian
hydrogeology, its history and its future, through a collective reflexive process. This paper examines the way
in which the world of Sahelian hydrogeology has been structured over time and its current configuration
from three perspectives. The first one deals with the history of the discipline in the considered countries,
within a close link to international cooperation. This history contributes to define a claimed “identity” of
Sahelian hydrogeology within a strong relation to geology, grounded fieldwork and the practitioners. The
second examines the way in which the discipline is defined via the skills its practitioners consider essential,
and how this is translated in the Sahel. It focuses in particular on the challenge faced by hydrogeologists in
being heard or even seen, whether in institutions (ministries and administrations) or in professional circles
(NGOs, consulting companies, etc.). While a discourse on the “invisibilisation” of the discipline is being
developed, the “boundaries” of the discipline are being affirmed. The third angle will analyse, in the light of
the two previous points, the diagnosis of the contemporary situation of Sahelian hydrogeology made by the
“experts” (academics, students, practitioners). Avenues for solving some of the difficulties will be discussed.