Explotation of groundwater resources. an alternative to supplement the water supply to Bahia Blanca, Argentina

Abstract

The arrival of dry rainfall years resulted in the lowest historical levels of the Paso de Las Piedras dam, which supplies drinking water to Bahía Blanca city, Gran Bahía Blanca and Punta Alta. This situation created a “water crisis” that is mostly due to control and management problems, than to the lack of technical projects or the availability of the water resource. This contribution aims to demonstrate sustainability of exploitation of groundwater resources to supplement the water supply. The study area covers a sector of the Napostá Chico stream watershed in the southwestern slopes of the Sierras Australes range, Buenos Aires province. The unconfined aquifer is located in the “pampean sediments” widely distributed throughout the piedmont plain. Available hydrogeological information allowed to formulate a numerical flow model by means of the Modflow program. Pumping scenarios were simulated and their impact on the hydrodynamics of the aquifer was tested. The results demonstrate the feasibility of extracting groundwater through a well battery located in close proximity of Cabildo locality. A rational exploitation of the aquifer, sustainable in time, constitutes a viable alternative to alleviate the critical water situation.