African Wildlife and Environment Issue 65

CONSERVATION

CONSERVATION

is shown as the inset. From this it is evident that the water quality deteriorates because of the inflow of contaminated water out of Gauteng. At the Bloemhof Dam there is an improvement, as the saline water is diluted via inflow from the Vet River. The DWA Vaal Salinity Study found that 34% of the salt entering the system came from the mine void (13%) and sewage return flows (21%). A further 39% originated fromdiffuse sources includingmine tailings dams. The study noted that although the volumetric contribution of water from mining was the lowest, the actual contribution in terms of salt concentration is the highest. The conclusion to this study was that two actions had to take place as a matter of urgency:

2020, which meant that the deficit would be half a decade only. The long-term management of the salinity problem is mitigation in the form of desalination to remove the salts before they entered the system. The impact of this is shown in Figure 3 as a dramatic improvement in yield in 2015, as fresh water would no longer need to be used to dilute the salt load. This improvement in yield would buy enough time for Phase II of the LHWP to come on line, thereby aligning demand with supply from 2020. It must be noted that this mitigation strategy needed two critical elements to succeed. Firstly, it needed all of the AMD to be desalinated

Figure 3. Vaal system water balance in terms of the mitigation component of the 2006 Salinity Study showing the improvement of system yield as desalination of AMD and improvement to sewage return flows reduced the need for dilution. (Source: DWA AMD Study, 2012).

the system to crash. This was caused by three critical failings of the state. The first is the missed deadline for Phase II of the LHWP, apparently to swing a tender over to a politically connected entity already under investigation by the serious crimes unit for tender irregularities. The second is the failure to desalinate the AMD. The three plants only neutralise the acid, leaving at least 3,000 ppm salts, so the water being released is not treated as claimed, still requiring the release of fresh water for dilution. The third is the fact that the El Nino drought remained invisible until it struck, largely because of the failure of data capture and management systems to measure streamflow and rainfall across the entire country. The combined impact of these three systemic failures means that the Gauteng economy will be water insecure at least until 2025, the date that first water can flow from Polihali Dam (assuming no further delays). It also means that the Gauteng economy, which contributes around 65% to the national economy and sustains 45% of the national population, has been compromised by policy failures. More importantly from an environmental perspective, it means that the Vaal River will remain distressed as the aquatic ecosystem is expected to assimilate between 500 and 1,000 tons of salt every single day. The ‘treatment’ of AMD only neutralises the acidity, but does not eliminate the salts. I leave the reader to draw their own conclusions regarding the optimistic picture presented by the media reporting on the launch of the third AMD neutralization plant in February 2017 by presenting the inconvenient facts

distilled from the DWA’s own reports on the matter. The harsh reality is that water security for the Gauteng economy will only be possible by 2030 as claimed if both Phase II of the LHWP and the full desalination of the neutralised effluent currently being discharged from the three AMD ‘treatment’ plants takes place on schedule.

Figure 2. Vaal system water balance in terms of the dilution component of the 2006 Salinity Study showing the dramatic crash in yield as the El Nino drought gripped the country. (Source: DWA AMD Study, 2012).

dilution (to minimise the impact) and mitigation (to remove salts at their point of origin). The short-term management strategy of dilution needs the releaseof water fromthe LesothoHighlands Water Project (LHWP) and Tugela-Vaal inter-basin transfer scheme. The unintended consequence of this is shown in Figure 2 as a dramatic loss of system yield starting in 2010, but transitioning to deficit in 2015. Yield is water surplus to need, or supply that is guaranteed to the end user. Demand continues to grow, because the increasingly restless population needs jobs via economic development. The date 2015 is significant for two reasons. Firstly, it was the start of the major El Nino drought that devastated the regional water resource and agricultural output. Secondly, it was the date that the contract needed to be finalised for Phase II of the LHWP (Polihali Dam). This date is critical, because if the contract was signed in 2015, the first water would flow from Phase II in

in order to remove the salt load. Secondly, it needed an improvement in the management of sewage return flows. Had the first element been successfully implemented, then the largest driver of salinity would be removed permanently. This was never done however, so the resource water quality management rules necessitated the release of fresh water in order to dilute the salinity, at the very time that the El Nino drought demanded that all water should be conserved. Clearly this was catastrophic and unplanned, putting economic development and social stability at risk. It’s against this background that the underlined statements made by the Minister in February 2017 during the opening of the third AMD treatment plant must be evaluated. Rather than an example of proactive water resource management deliberately designed to improve water security, it was a clumsy attempt to justify a reactive response that caused

Anthony Turton Professor: Centre for Environmental Management, Univeristy of the Free State

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