Water footprint assessment to inform water management and policy making in South Africa
One method to inform decisions with respect to sustainable, efficient and equitable water allocation and use is water footprint assessment (WFA). This paper presents a preliminary WFA of South Africa (SA) based on data for the period 1996–2005. Crop production was found to contribute about 75% of the total water footprint of national production. The total water footprint of crop production is mainly composed of five crops: maize, fodder crops, sugarcane, wheat and sunflower seed, which account for 83% of the crop water footprint. The average water footprint of a South African consumer is 1 255 m3/yr, below the world average of 1 385 m3/yr, and is dominated by the consumption of meat (32%) and cereals (29%). About one fifth of this water footprint of consumption is external to SA. While SA is a net virtual water importer, the virtual water trade analysis revealed that a large share of blue water consumption is related to export. Sustainability concerns are that the major river basins face severe blue-water scarcity for extended periods of the year, and that water pollution levels related to nitrogen and phosphorus were found to be unsustainable in all river basins in SA. Efficient allocation and use of water is investigated by means of comparing the consumptive water footprint to global benchmark values, as well as the economic green- and blue-water productivity and the economic land productivity of the crops cultivated in SA. Furthermore, crops with specific potential for biofuel production are assessed. Lastly, recommendations to address the identified issues are given.
Keywords: water footprint assessment; water management; water policy