Bart Schultz
Argentina has an exceptionally diverse climate, ranging from subtropical in the North to polar in the far South. Average annual rainfall ranges from 150 millimetres in the driest parts of Patagonia to over 2,000 millimetres in the westernmost parts of Patagonia and the northeastern parts of the country.
The country has four very deep depressions. The lowest point is the Laguna del Carbón in the Great Depression of San Julián at 105 metres below mean sea level. In addition, there are three other deep salty depressions: Salina Grande and Salina Chica at 42 metres below mean sea level, and the Gran Bajo del Gualicho at 41 metres below mean sea level. However, there are no polders here, it are natural depressions, which are not inundated due to the dry climate.
In 2001, there was a bilateral Argentine - Dutch symposium in Buenos Aires on Sustainable water management and flood control in the area Pampeana Central and Bajos Submeridionales. In the context of this symposium, I was allowed to make a sightseeing flight with a small delegation over the Pampeana Central area. We took off from a local airport in Buenos Aires. We flew a bit over the city with millions of people. After a while, there was the adjacent countryside. This offered an enormous, very sparsely populated expanse, with lowlands and sometimes hills. We were told that the vast lowlands in Argentina were flooded from time to time. There were also a few polders in these areas. In short, we got a good impression of an overpopulated city with an adjacent, almost empty rural area.
The same must apply more or less to the Paraná Delta, where several areas are inundated for the greater part of the year. Canals have been constructed for both drainage and water transport. The spoil from these canals has often been dumped on the banks, thus forming in a certain sense dikes, which are built and inhabited just like the natural levees. The lower parts of the areas have been drained in a number of places by open drainage watercourses, so that the lands can be cultivated.
The population lives scattered along the rivers, navigable creeks and canals. Due to the frequent flooding, most people live in pile dwellings. As a result, even the largest floods result in a few casualties. In some places, a certain degree of protection against flooding has been created by surrounding the fields with dikes. These dikes are high enough to keep out regular flooding, but are not resistant to large floods. Dikes around urban areas are designed to prevent flooding with a chance of once in a thousand to ten thousand years. In these cases, it clearly concerns polders.
During the international symposium on Polders of the World, which was held in 1982 in the then Agora in the city of Lelystad, the Netherlands, Dr. Sallabar from Argentina presented a list of polders in the Paraná delta in the vicinity of Buenos Aires. The total surface area of the twelve polders was over 44,000 hectares. He also presented a proposed open polder of 90,000 hectares in the delta. This project would be a first phase of much larger land reclamations. It is difficult to determine whether the proposed land reclamations were actually implemented.
