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Tim Mersoï basin
The Tim Mersoï basin is a vast aquifer reservoir of about 115,000 km² in northern Niger, between the Aïr massif and the Algerian border. It holds deep fossil aquifers (the Tarat and Guézouman aquifers) and still-active shallow aquifers — the main water source for Saharan populations and the mining towns of Arlit and Akokan.
Details
- Area: ~115,000 km² (northern Niger, Agadez region)
- Deep fossil aquifers: Tarat (Carboniferous) and Guézouman (Devonian), 150 to 600 m
- Strategic but pressured resource (cone of depression around Arlit, mining abstraction)
- Shallow aquifers vulnerable to climate variations and pollution — sustainable management essential
Frequently asked questions
Where is the Tim Mersoï basin?
In northern Niger, Agadez region, between the Aïr massif and the Algerian border. It covers about 115,000 km² and supplies the mining towns of Arlit and Akokan.
Is the Tim Mersoï basin's water renewable?
Only partly. The deep aquifers are mostly fossil water, barely renewed. The shallow aquifers receive natural but limited recharge. Current abstraction often exceeds recharge, hence the need for sustainable management.
Related terms
- Fossil water — Fossil water is groundwater that infiltrated thousands, even tens of thousands of years ago, during the humid periods of the "green Sahara", and has been trapped since in deep aquifers.
- Water access in Niger — In Niger, access to drinking water is among the lowest in the world: 2 out of 5 Nigeriens have no access to safe drinking water.
- Solar borehole — A solar borehole is a deep borehole (typically > 80 m) equipped with a submerged pump powered by photovoltaic panels.
- Agadez Region — The Agadez region is the largest in Niger: 667,799 km² (equivalent to the area of metropolitan France), 714,509 inhabitants (INS 2024).