Estimating groundwater recharge for a carbonate aquifer: Case of Wonderfonteinspruit Catchment (South Africa),

Groundwater recharge is a key parameter needed for the calculation of water budgets, which are necessary for accurate sustainable groundwater management. In this context, the quantification of groundwater recharge in karst aquifers situated in the Wonderfonteinspruitcatchment (South Africa) is an important, yet not easy task to address. This catchment is divided into six groundwater compartments (Zuurbekom, Gemsbokfontein,Venterspost, Bank, Oberholzer and Boskop-Turffontein Compartments) by mostly north-south trending dykes. In reality, natural groundwater recharge of the study area has been intensely affected by a lack of precipitation. In this paper the recharge rateswere estimated for these compartments using various recharge methods including the Chloride Mass Balance method, Saturated Volume Fluctuation (SVF) method, Kessler method, APLIS method and Thornthwaite method. The results suggested that the SVF method is the most accurate method for showing the recharge rate ((12.1%)Zuurbekom Compartment, (14.24%)Gemsbokfontein Compartment, (15%)Venterpost Compartment, (19.66%) Bank Compartment, (11.80%) Oberholzer Compartment and (4.85%) Boskop-Turffontein Compartment).