La teoría de Florentino Ameghino y el Plan Maestro Integral Cuenca del Río Salado en el tramo de la desembocadura en la Bahía de Samborombón

Abstract

The Theory of Florentino Ameghino and the Plan Maestro Integral Cuenca del Río Salado at the mouth in the Samborombón Bay. A retention dam building proposal. Florentino Ameghino established that the Buenos Aires Province needs retention structures and not drainage ones in order to prevent drought and flood events. In the lower Salado River drainage basin, Channel Aliviador and Channel 15, that reach the Samborombón Bay, were built with the purpose of control water excess during flooded periods. But Channel 15 was made wider and deeper during 1997, then almost all the water coming from the river goes directly to the Samborombón Bay and this causes a lesser supply of freshwater, that promotes a change in the ecological and socioeconomic conditions in that region. As a consequence, the government taking into account the results of the project Plan Maestro Integral Cuenca del Río Salado (PMI), decided to build threshold bottom dams in the two channels. On the other way, near the mouth of Samborombón Bay, it is located the rock shell littoral chain, which generates an aquifer of a low salinity water. At present, hydrochemical studies indicate that the absence of the river makes the water of the aquifer goes to the bed of the river, which reaches the bay in the moment of low tide and, on the contrary, during high tide a mix with high salinity water coming from the bay takes place. In both cases a loss of freshwater occurs. So in order to minimize this effect, the construction of a retention dam was suggested in a previous work. Since, once the dams of the PMI will be concluded, still a probability of a lack of water may persist in case of drought event as well as for the intensive use of water in the rest of the drainage basin, then the aim of the present work is to maintain the proposal of the construction of the retention dam to assure a source of freshwater in the region and to preserve the rock shell littoral chain aquifer.