Previous workers maintained that rain recharge in the Kalahari is inhibited by the covering sand. According to this model, which has been much cited in the literature, the rain fills the pores in the upper part of the sand and is subsequently lost by evapotranspiration during the dry seasons. Direct observations on groundwaters indicate, however, that in parts of the Kalahari recharge is active. This is evidenced by elevated tritium and 14C values, rises of the water table following above-average rainy years and a steady supply of water in shallow wells.