Compromised water availability and quality is the hidden cost of loadshedding

Posted on 12 May 2023

Loadshedding is not only an energy supply issue. It also threatens water security with serious implications for food systems and environmental health, writes Caroline Gelderblom.

As South Africans, we have lived with loadshedding in some form or another for 16 years. But the severity and regularity of these rolling blackouts has become debilitating, frustrating people and stalling the economy, and its impacts are permeating every area of our lives.

What has energy got to do with it?

One of the more serious impacts of loadshedding is on South Africa’s water security. Indeed, if it continues at current levels it threatens many industries and in particular the production of irrigated crops (and therefore food security), while poor water quality also poses a direct risk to human and environmental health.

In terms of water supply, electricity is needed to pump water from dams, rivers and boreholes to cities and farmers. Although some of these pumps can be powered by diesel generators this is a much more expensive option than using power supplied by Eskom.

Individual farmers have indicated that it currently costs them four times as much to irrigate their crops using generators. Not only is the diesel itself more expensive, but generators require more active management and maintenance, with the associated increasing labour costs. If pumps are really critical, a second back-up generator must be available in case the first one fails – requiring even more capital costs and maintenance.

In the past six months, urban residents in high-lying areas where reservoirs need to be consistently filled to maintain pressure have experienced water shortages during loadshedding.

Big metros are in the process of installing back-up generators or alternative power supplies for their critical pump stations or are exempting them from loadshedding, but this remains a significant challenge for many smaller towns.

The South African Local Government Association (SALGA) has expressed its concern and notes that regions such as KwaZulu-Natal have very complex water transfer systems whose high-lift pumping systems are now exposed to greater vulnerability in terms of water security during loadshedding. Umgeni Water therefore has exemptions for critical infrastructure for independent and multisource power lines but this is not guaranteed above Stage 4.

Loadshedding also presents a challenge to scheduled extraction of water from boreholes or water schemes. Inability to extract water at an allotted time means that everyone tries to access water simultaneously when power is available which can lower overall availability.

To compound the problem, changes in water pressure and power surges contribute to increased failure of water infrastructure including pipe bursts and pump breakages. Exacerbating this situation is an increase in vandalism of infrastructure during loadshedding periods noted by both municipalities and farmers leading to further failures.

Many industries have had to install protective measures against disruptions in water supply. The situation is particularly acute for farmers using hydroponic systems who need to irrigate their tunnels up to nine times a day in summer. Vegetable, flower and farmers of other annual crops including those under tunnels are more vulnerable to disruptions in water supply and as little as one day without water in summer can reduce the yield of crops so severely that it becomes uneconomic to harvest. Strained supply chains are not able to absorb further increases in costs so farmers are responding by planting less.

Water User Associations indicate that some large irrigation systems draw power from two areas and as the whole system needs to have power to be functional they can lose 16 hours a day under Stage 6 loadshedding. This is exacerbated by the fact that it can take up to two hours to balance the pressure and synchronise all the outlets and relieve airlocks once the system receives power. As a consequence, they simply are not able to supply sufficient water to their users, which has a significant impact on production.

Water quality concerns

Without even factoring loadshedding into the equation, in many areas we already have significant water quality challenges.

The 2022 Green Drop report, through which the Department of Water and Sanitation evaluates the functioning of South Africa’s Wastewater Treatment plants, indicates that 88% are high risk as a result of exceeding their design capacity, dysfunctional processes and equipment and non-compliance and that scores have in general declined since 2013.

This report does not as yet however appear to explicitly measure resilience to the impacts of loadshedding which is a compounding reality and proactively needs to be addressed.

In addition to the challenges in getting enough water supplied to users, loadshedding also has a severe impact on water quality. It is much more difficult in some areas for municipalities to produce clean drinking water as water treatment plants need to maintain pressure for sand filters to operate. Wastewater treatment plants have biological filters containing bacteria which require active aeration to survive and function. Electricity is also required to produce chlorine required to ensure the compliance of the final effluent in terms of E.coli standards.

Although many wastewater treatment plants have holding ponds/wet wells which enable them to manage short periods of loadshedding, longer outages result in them exceeding their capacity which can result in sewerage spills, particularly when the outages take place during the peak morning and evening use periods.

This past summer, sewerage contamination associated with loadshedding has resulted in numerous beach closures and impacted the quality of water in several rivers and water bodies used for irrigation and recreation.

What can we do to address this?

The poor quality of river water in some areas has already forced farmers to install expensive purification systems for irrigation systems in order to meet safety standards. Problems in managing water quality accumulate downstream and make it more difficult for municipalities further down the river to treat water to adequate standards.

Indeed, outage-related impacts on the functioning of wastewater treatment plants led to some municipalities to recommend that users boil water. Emergency measures which have been used in better resourced areas include additional support crews, mobile generators and suction tanks to contain sewerage spills.

Municipalities can reduce water pressure to decrease flows and reduce probability of reservoirs running out or wastewater systems overflowing. They can also explore the use of alternative technologies such as biogas, wind and solar to support wastewater treatment plant functioning.

Communities and industries should also be made aware of the need to use less water to alleviate pressure on the system by reducing flushing and washing, particularly when loadshedding is underway.

More systematic monitoring of sewerage outfalls and rivers is needed to determine and address potential danger to human and environmental health. Substantial investment in backup systems for water treatment and wastewater plants is critical.

There are also opportunities presented by this crisis to invest in improved energy efficiency and alternative energy sources for the water supply system and reuse of resources and by so doing ensure that we do have clean and accessible water for all forever.

We are therefore encouraged by the establishment of a Water Partnerships Office where the Department of Water and Sanitation (and established Catchment Management Agencies), in partnership with SALGA and the Development Bank of South Africa, are working towards investment supporting reuse of water as one of the solutions to this ongoing challenge.

Caroline Gelderblom works on WWF South Africa’s freshwater programme.

Without even factoring loadshedding into the equation, many of our rivers are already polluted.

Compromised water availability and quality is the hidden cost of loadshedding

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