We are at 19e century, more precisely in 1864. That year, theofficer Roudaire, recently graduated from Saint-Cyr and a student at the Staff School, was sent to Algeria. He discovers the chotts, these lakes which fill with water after the winter rains, in the region of Biskra, in Constantine, in the heart of the Sahara. In the mind of the young officer the beginnings of a crazy project then took shape, which would become that of the “Roudaire Sea”.
An astonishing discovery
His idea was born when he accurately measured the depth of these lakes. In 1872, back in Algeria after the war, he assembled the results obtained during his various cartographic research. Roudaire thus discovered the existence in the Gulf of Gabès of a major depression located below sea level, sometimes up to 40 meters deep.
It is then certain, this depression is the old bed of a now dry sea: the bay of Triton, whose traces go back to the time of ancient Greece. It is the birth of Commander Roudaire's incredible project! In an article published on May 15, 1874 in the Revue des Deux Mondes, he submitted the idea of re-establishing this sub-Saharan inland sea using a canal dug in Gabès.
The missing sea thesis
This arid land seems to have sheltered life once. Paintings, cut flint, eroded trunks and traces of vegetation are indeed found on the site. One conclusion is obvious to the officer: a civilization would have lived in the middle of the Sahara, thousands of years ago. It would certainly have developed around a sea that has disappeared about 400 kilometers long and fed by four rivers: the Souf, the Ighargar, the wadi Miya and the wadi Djed.
However, there is no answer to explain the disappearance of this entire ecosystem. However, the proofs of its existence are indeed there: in the chotts, he discovers shells, pebbles and significant salt concentrations.
A crazy project to refertilize the Sahara
Roudaire is convinced of this: connecting these chotts, once sanitized, to the Gulf of Gabès by canals which would convey the waters of the Mediterranean would make it possible to recreate an inland sea with an area of 8 km². The climate of the past would then be restored, tempered by the rains resulting from the evaporation of this enormous mass of water. The latter could even give birth to rivers and make the land fertile again, thus solving the problem of lack of water in North Africa.
This crazy idea finally conquered the politicians and scientists of the time. They indeed perceive there the means of proving the superiority of the French civil engineering whereas the country has just lost Alsace and Lorraine… Ferdinand de Lesseps, famous promoter of the Suez Canal, renames the future body of water the "Roudaine sea".
The end of a dream
The project seems to be on the verge of taking shape. For the modest sum of 20 million francs, it promises a sea of 24 meters deep and 8 km² in area, as well as humidity suitable for cultivation.
But Roudaire's dream ended on July 27, 1882, when a higher commission "of the Inland Sea" of the Academy of Sciences delivered an unfavorable verdict. Discouraged by incessant scientific opposition, he died in Guéret in 1885. His name will remain unknown, but the history of his project will survive him ...
© Photo: Javier Collarte