Recharge assessment in an urban area: a case study of La Plata, Argentina

Leakage from water mains, storm drainage and sewer systems in urban areas constitutes a source of recharge that is difficult to identify and quantify at a regional scale. The objective of this work is to apply a methodology that would make it possible to evaluate urban recharge at a regional scale, taking as a case study the city of La Plata (Argentina). In the study area, population growth and an increase in water demand has caused the intensive exploitation of groundwater with resulting alteration in groundwater flow. The methodology used was developed on the basis of a water balance and the simulation of the temporal evolution of the cones of depression and the volumes of water extracted from the aquifer. The method consists of adjusting the piezometry resulting from the numerical modelling to the measured piezometry, by means of the variation of the recharge parameter in the urban area. The results obtained make it possible to identify and quantify urban recharge, which in this case represents a volume of water similar to the recharge from precipitation.