This lake is located on the centre edge of the Ebro basin. This basin was filled with sediment during the Tertiary period, at the same time as Alpine orogenesis was raising the Pyrenees to the north and the Prelitoral mountain range to the south and southeast. In the beginning, it was occupied by the sea and sea sediments were deposited there. Little by little, this basin closed and plaster and salts were deposited. Finally (in Oligocene) it was completely closed and it was filled with continental sediments.

In general, the morphology is very smooth with few prominent terrains. The Ebro river and its tributaries run there, the most important being the Segre. In this area, the landscape is very flat, and the sediments contributed by the rivers (sands and gravels) abound. This morphology of a river plain, favours the existence of lagoons, like the one in Ivars.

It is an endorheic, seasonal lagoon, originally from brackish water, of which there were many in the Ebro depression and this was the largest in Catalonia. By 1862 this area was converted into a large irrigation reservoir, coming from the recently constructed Canal d'Urgell. It is, therefore, an example of a living, humanised landscape.