Hydrogeological disarrays in Buenos Aires area and its surroudings, Argentina

Abstract

As a consequence of the accelerated population and industrial growth in the Greater Buenos Aires (12,500,000 inhabitants), there was a intensive exploitation of the semiconfined aquifer (Puelche aquifer) wich generated extensive regional drawdown cones. In addition to the drastic declining of piezometric levels, an intrusion of saline water forced the closing of many exploitation wells. Another consequence of overexploitation was an acceleration of leakage from the phreatic aquifer through the aquitard,thus causing pollution with nitrates, HC´s and heavy metal and a strong drawdown of phreatic levels. In order to compensate for the deficit caused by the depletion situation, surface water from two treatment plants in the River Plate was imported since 1980´s. The closing of exploitation wells and the import of water brought about a rising of the phreatic surface when leakage ended, thus causing serious troubles such as waterlogging of underground facilities (parking lots, basements, power distribution installations), a situation that has become critical in many areas in the surroundings of Buenos Aires City.