We ignore nature at our peril — how Centurion Lake became a man-made disaster

During my national water security career I had the privilege of travelling widely. I was always struck by the fact that in water-constrained countries, the very presence of water was something of great value.

Outside the military barracks in Cairo, a large water feature is clearly visible. The pharaohs of ancient Egypt derived their authority from their ability to predict the flooding of the Nile, which was associated with prosperity. Closer to home, the overwhelming presence of water at the Cascades makes the Sun City experience one to be remembered.

It was with this type of thought that I watched the high-value real estate being developed around Centurion Lake – what used to be a muddy trickle of a stream made famous by Winston Churchill who embellished his escape story by referring to the rivers he had to cross during the Anglo Boer War.

What used to be marginal land on the outskirts of Pretoria was suddenly transformed into high-value commercial real estate, all centred on a man-made lake. Musical fountains shot into the air as light displays created an air of adventure in the night sky. Restaurants were fully booked as people came to experience the wonder of Man’s control over Nature in a water-constrained country. It was truly a wonderful experience, and I lived through it all.

Then nature bit back with a vengeance.

You see, the designers were obviously not familiar with hydraulics in rivers and had based their assumptions on the absence of illegal sand mines. Every river carries a sediment load, and the velocity of the flow determines the amount of sediment that is carried. The basic principles are easy to grasp.

As the very small river enters the large man-made lake, two things happen. The velocity decreases and the sediment load is deposited as a result. Voila, just like that, your shallow, open lake starts to become a narrow river once again, as sediment is consolidated into islands, and natural vegetation converts these into a wetland.

This process was accelerated after illegal sand mining operations gained a foothold in the areas that feed the Olifantsfontein Wastewater Works. This is now a material factor in the dysfunction of the Ekurhuleni Water Care Company plant, along with fats, oil and grease, and of all things, clogging of the machinery by chicken feathers.

Centurion Lake is now a wetland, which was never in the designer’s mind. To make matters worse, the incoming water is heavily contaminated by sewage.

Lake Centurion has all the perfect ingredients for an experiment in solution-seeking to be conducted.

The Olifantsfontein plant is designed for 110 million litres a day, but it receives almost double, so it is unable to process the sewage. The wetland is choked by what most perceive as unsightly reeds, and the air is pungent with the smell of decaying faecal matter. 

The fountains no longer play music, and the night shows are unable to attract the crowds that used to keep the restaurants full. Centurion Lake became a man-made disaster, and politicians regarded it as a hot potato best avoided.

Mountains of sand, the byproduct of illegal mining, have to be mechanically removed, but this is complex because it is contaminated with heavy metals, so it has to be disposed of as hazardous waste.

A solution

We know that ingenuity happens on the cusp of chaos, so how might this sorry saga be turned around?

This shifts the spotlight onto Hennops Revival, an NGO doing amazing work, often against overwhelming odds. Let us apply our minds to possible ways that their good efforts might be supported. Let us engage in a thought experiment in solution-seeking, to cleanse our mind of the cancer of blame-apportionment. Let us create a better future by embracing the forces of nature as we transition from a linear to a circular economy.   

Let us imagine that all the commercial real estate owners unite in the face of a common challenge. Let us assume that the large corporations who are already located there are willing to follow suit. This means that a powerful special interest group can be invited to the party.

Then let us assume that those large public companies already have corporate social responsibility (CSR) budgets available. All the building blocks for a successful outcome start to emerge, as three defined objectives can be quantified in financial terms.

Read more in Daily Maverick: Healing waters – a Centurion eco warrior’s journey from abuse to a mission to clean rivers

The first is the cost to the economy of illegal sand mining that creates the sediment clogging up the shallow lake. The second is the cost to the economy of releasing untreated sewage down the river. The third is the opportunity cost of doing nothing. From these three mathematically defined parameters, we can begin to quantify the benefit being conducted by any remediation in that overall system.

It all comes down to the quantification of costs and benefits in a verifiable way. This is crucial, because without the verification process, fraud will enter the system like a pathogenic virus.

Once this has been done, units of value can be linked to actual improvements in the system. With such tokens now of known value, they can be traded, and revenues can begin to flow between those directly affected, and those who have the capacity to effect change.

Instead of complaining about our water problems, let us rethink the opportunities that are all around.

Specific projects can be quantified in terms of the overall benefit they create to society as a whole. This, in turn, opens a whole new dimension to the rethinking of CSR.

What makes Lake Centurion such an interesting case study is that it has all the perfect ingredients for an experiment in solution-seeking to be conducted. More importantly, it is already home to two major corporations that have consistently been willing to put their money where their mouth is – Exxaro and OUTsurance – whose support for Hennops Revival is a matter of public record.   

This is a callout to the CSR managers in large corporations physically located around Lake Centurion: How can you get the biggest bang for your buck by investing it into rehabilitation projects that directly mitigate the risk your companies face?

This is also a callout to the commercial real estate owners, developers and landlords operating around the lake: How can you best cooperate to collectively benefit from a sustainable clean-up of the system? 

This is a callout to the municipal, provincial and government officials: How can the digitisation of the entire water value chain under your direct responsibility strengthen your regulatory roles and create different revenue streams for the funding of infrastructure maintenance?

Read more in Daily Maverick: Seeing Red: Water crisis should be SA government’s biggest priority, seminar told

And finally, this is a callout to the professionals operating in the digital twin and Internet of Things space: How can your technologies be used as a platform for the creation of a new class of fungible asset known as a tradeable water credit?

This is a good-news story, for South Africans are highly innovative people. Instead of complaining about our water problems, let us rethink the opportunities that are all around. Let us turn the Lake Centurion environmental catastrophe into a crucible of innovation, as we harness the potent energy of change, and convert it into the light of solutions, rather than the heat of anger.

The Lake Centurion problem is entirely fixable, so let us work together to figure out how it can be done, and what the future landscape will look like. DM