Engineering will solve the Joburg water supply problem, not short-term political games

A few months ago, the leadership team at the Department of Water and Sanitation announced the creation of a Platform for a Water Secure Gauteng (PWSG). Its purpose is to align all the stakeholders across the entire water value chain, so that their combined actions can be synchronised to avoid Day Zero arising from the imbalance between demand and supply in the integrated Vaal River system. 

Initially there was some blame-shifting, as each party tried to deflect responsibility for the failing infrastructure onto other parties. There are many parties across the entire value chain, but the trend has been to shift blame upstream to the water board. This is currently happening as politicians and officials respond to angry constituents who are inconvenienced by maintenance jobs. The biggest current maintenance job is the upgrade by Rand Water to the Eikenhof pump station, scheduled for 13 December. The expected shutdown will be 86 hours, or three and a half days.

Eikenhof is a critical bottleneck in the overall Rand Water grid, because many end users receive their supply via this single pump station. The upgrade is therefore of great importance to overall system stability, and it has been carefully planned to take place over the summer holidays when most factories and businesses are closed, meaning that water demand is at the lower end of the spectrum. 

Large pipeline networks like those operated by Rand Water all have redundancy built into the design. Redundancy means that critical items like pumps are routinely rotated through a precise duty cycle. Typically, there are three pumps in a station. All are identical and are connected in parallel, meaning that any combination can be used as required. One is in constant use, with the second on standby for peak demand. The third is shut down for routine maintenance. This duty cycle is rotated across the fleet, ensuring that all three pumpsets are in equal operation over time, but none is overused. The original design was based on lower flow projections, so the pump station has become a known weak link in the overall supply chain as the volumes have increased. 

Read more: Water shortages

The planned work will mitigate this risk by creating greater flexibility. More importantly, it will enable the pumps to be operated independently as required, thereby reducing the impact of any shutdown. The decision to perform this critical task on that specific day was based on the cooperation of all municipal stakeholders, who would each be responsible for filling their reservoirs before the shutdown, and then managing the demand in their area of supply for the three and a half days of outage. 

This raises the issue of the structural integrity of reservoirs, because those with major leaks cannot be filled by the municipality concerned. This is why a priority of the PWSG is the repair of leaks across the entire network, along with an increase in the strategic storage capacity within each municipal network. The system will be fully operational again by Christmas. 

In the past Rand Water has executed complex maintenance procedures with precision. This has generally meant that the shutdown tends to be for less time than planned, but this cannot always be guaranteed, simply because things can go wrong during major engineering upgrades. 

It is unfortunate that some ward councillors are pre-empting this by laying the foundation for blame-shifting once again. It is important that the public realises the benefit of a stable water supply, so any distraction caused by opportunistic councillors ought to be condemned by the citizens on whose behalf they are shifting blame. Real engineering will solve the problem, not short-term political games.

This is a call for support of the PWSG, because it is in nobody’s best interest that the Gauteng economy is negatively affected by the loss of water security. DM