To evaluate the efficiency of allocation and use of water resources we investigated those 20 crops (out of 51 – see Appendix) that have the largest average total water footprint of production for the time period 1996–2005 in South Africa (see also Fig.1). These 20 crops account for 97% of the total green-, 87% of the total blue- and 91% of the total grey-water footprint of production,
and overall for 95% of the average total water footprint of production for the time period 1996–2005. In addition we consider the most important livestock products.