Removing weeds can improve a dam's appearance. Keeping them from returning means understanding what is happening beneath the surface and in the water flowing into it.

That is the challenge behind efforts to revive Lonehill Dam, where the residents’ association is working with environmental specialists, engineers and Johannesburg City Parks and Zoo on a restoration project. The association identifies ageing infrastructure, water loss and environmental pressures among the problems requiring attention.

Looking Beneath the Surface

During a site visit reported by Fourways Review on 30 October, specialists presented proposals for continuous water monitoring and biological sludge treatment.

Agricultural Research Council researcher Dr Kyle van Heyde proposed establishing baseline water-quality measurements, assessing accumulated sludge and mapping the dam’s underwater depth and shape. Those assessments would help guide rehabilitation decisions.

What Could the Technology Do?

Kyle Odgers of Mobile Blue presented a monitoring approach using sensors linked to a dashboard. Depending on the equipment installed, these could track:

• Dissolved oxygen: Oxygen available in the water.
• Temperature: Changes in how warm or cold it becomes.
• Turbidity: How cloudy the water is.
• Chlorophyll-a: A pigment used to help assess algae levels.

Continuous readings could reveal changes missed by occasional sampling. Odgers said comparing monitoring points could also help narrow down where pollution enters the system.

The proposed sludge treatment, described as in-situ biodredging, would aim to break down accumulated organic material within the dam. 

Progress Needs Clear Evidence

There are encouraging reports, but the precise implementation stage needs clarification.

SAnews reported on 30 October that rehabilitation was underway, attributing reduced weed growth and a lighter maintenance workload to the residents’ association. However, Fourways Review’s account published that day described the monitoring and sludge-treatment interventions as proposals without a confirmed implementation date.

The accounts do not establish which elements are operating and which remain planned. They should not be read as confirmation that the dam is fully restored.

Why It Reaches Beyond Lonehill

The dam forms part of a wider water network. SAnews reports that its outflow ultimately reaches the Jukskei River and Hartbeespoort Dam.

Addressing pollution here could therefore have downstream benefits. Sustained improvement also depends on dealing with sewage and other pollution entering the system, rather than repeatedly treating what accumulates in the dam.

Residents can follow the LRA’s Dam Revival Project. Community clean-ups must be arranged through nadeem@lra.org.za, at least a week beforehand. 

The Bottom Line

The next useful milestone is a clear update showing which interventions are operating and what the measurements demonstrate. Better monitoring could help guide restoration, while stopping incoming pollution remains essential to protecting the progress made.