Geology & Hidrology
A set of lakes in a tectonic depression.
The Janda lagoon complex was located on a tectonic depression which poured its waters originally Barbate, Almodovar, Celemin and other minor rivers.
When the year was exceptionally rainy these rivers were overflowing and, given the limited capacity of drainage depression and impermeable clay background, much of the flooded tectonic depression forming a unique wetland of more than 50 km2 of shallow depth extension and mostly temporary, but in its deepest zone, "El Charco de los Ánsares" (the Geese's puddle), came to hold water all year and exceeded five meters deep.
As the dry season progressed the great wetland was breaking up in a string of lagoons of which the largest, with approximately 4,000 ha., Was the Janda and its periphery were other minor known by the names of Rehuelga, Espartinas, Cabrahigos, Alcalá, Jandilla, El Torero, Tapatanilla and Tapatana-La Haba.