Lake · Benin
Lake Ahémé
Lake Ahémé is a long, narrow lake in the south of Benin in West Africa, not far from the Atlantic coast. Its size changes with the seasons: about 78 km² in the dry season and up to 100 km² in the rainy season.



Picture credit: Kulttuurinavigaattori (CC BY-SA 4.0) · Magnificat.229 (CC BY-SA 4.0) · JulianGrayscales (CC BY-SA 4.0) · Wikimedia Commons
Where is Lake Ahémé?
Countries on its shores: Benin.
Largest lake of: Benin.
Middle of the lake: 6.50° N, 1.98° E
The story behind it
Lake Ahémé is about 24 km long but only a few kilometres wide. At its swampy northern end the Couffo River flows in. At the southern end the 10 km long Aho Channel leads to the Grand-Popo Lagoon on the coast. In the rainy season the water in this channel flows south. In the dry season it turns around, and the southern part of the lake becomes saltier. Scientists have counted 71 kinds of fish in the lake. Fishing and farming are the most important work for the people around it, most of whom belong to the Pedah and Ayizo peoples. Some fishers build acadjas: they push cut branches into the muddy bottom, fish gather among them, and later the fishers surround the branches with nets. Lake Nokoué near the city of Cotonou is often counted as bigger, but it is largely a lagoon joined to the sea by a canal. So Lake Ahémé counts as Benin's largest natural lake.
Find it on the globe
Lake Ahémé is there as a small blue dot with its name, right on the water. From far away the planet is only a blue ball; detail arrives as you zoom in, and this one appears once you are close enough. Open it on the globe.
It sits at its real coordinates, not near them — the same numbers listed in the facts above. Switch off the layer for this kind of place and it disappears again; the buttons for that are down the right-hand edge.
Questions children ask
How big is Lake Ahémé?
Lake Ahémé covers about 78 km² in the dry season and grows to about 100 km² in the rainy season. It is about 24 km long and on average about 3.6 km wide.
Why does the lake get saltier in the dry season?
In the rainy season the water in the Aho Channel flows south towards the coast. In the dry season it flows the other way, and the southern end of the lake becomes saltier.
What is an acadja?
An acadja is a kind of fish park made of cut branches pushed into the bottom of a lake or lagoon. Fish gather among the branches, and the fishers catch them by surrounding the acadja with nets.
Where these numbers come from
Every figure on this page was checked against public reference sources before publication. Where sources genuinely disagree, the text says so.
Last checked: