When geography matters. A location-adjusted blue water footprint of commercial beef in South Africa

Abstract

Should South Africa be concerned about the water use associated with its meat consumption? South Africa is water stressed: it is considered a nation approaching physical water scarcity and predictions foresee that by 2040 it will be facing high levels of water stress; meat consumption is on the rise; and there is a perception that the water footprint of meat is large. The aim of this work was to quantitatively assess a range of stressed-adjusted blue/consumptive water footprints (WF) for commercial beef in South Africa. Local environment was accounted for via local water stress indices (WSI).A comprehensive top-down approach to represent the South African commercial beef value chain was implemented. A model of a generic herd was developed, by using elements of a Life Cycle Assessment (LCA) approach as a guide to define the system. The main processes considered within the livestock value chain include: feed cultivation, primary production, feedlots and abattoirs. Water is used in growing feed, drinking and service water, and process water in the abattoir. A population balance was completed assuming steady state conditions; this was used to determine a basis population (1000 cows at the time of mating), which in turn has been used to determine the WF of beef. Beef cattle populations of reference were taken from Agricultural Censuses and the Department of Agriculture, Forestry and Fisheries. The geographical resolution of the study is at the level of water management areas (WMAs); local impacts via the Water Stress Index (WSI) were performed at WMAs resolution; a sensitivity analysis was performed in order to investigate possible scenarios.The base-case, unadjusted blue water footprint for commercial beef in South Africa is 437 L/kg carcass weight (CW). Adjusting for local environments, the best case (in locations with low WSI and low feed WFs) had a WFeq. of 105 Leq./kgCW. The worst case WFeq. was 2820 Leq./kgCW. The best-feasible case was based on the WMA in which the largest production or population for each of the major processes in the value chain was located. The resulting WFeq. was 276 Leq./kgCW, with a 2% probability of occurring. The feed contribution is significant ranging from 43% to 94%; the contribution from drinking and service water is non-negligible.Accounting for the local environment can change the result, and this study highlighted the central interior of South Africa to be an environmental hotspot. Since those areas are already water stressed, the sensitivity analysis results indicated the best-feasible scenario to pursue in order to reduce the WF of commercial beef. Knowledge of water use, water stress and water efficiency need to be considered in feed optimisation for intensive animal finishing. Relocation of the livestock-related activities must be considered especially for future drought-preparedness planning as well as future expansion of the livestock sector should be focused on less stress WMAs.