KIKUYU WETLANDS REHAB

March 2024

Nestled in the heart of our modern urban landscape, Waterfall City strives to be a beacon of sustainable living, aligning its development focus with strong environmental stewardship. To bring the public’s attention to this, Waterfall City aims to highlight some of its ground-breaking initiatives in line with several international commemorative days celebrating the environment. 

The plant provides irrigation water to several other estates in Waterfall City, as well as the entirety of Waterfall Drive and Polofields Drive. Managed by WCSC, the irrigation plant maintains the lush, indigenous landscapes We kicked off these celebrations in February 2024 by highlighting World Wetlands Day (2 February). As the name suggests, this day is designed to raise awareness and action for wetland protection. There is reason to argue that wetlands are ecological powerhouses. They are critical hubs of biodiversity, performing water purification functions while effectively controlling floods and carbon sequestration.

Masses of black wattle trees being eradicated. Black wattle (Acacia mearnsii) is problematic as it competes with indigenous plant species and reduces grazing capacity both for wild and domesticated animals.

These distinct ecosystems in waterfall City’s context form part of the last lingering vestiges of wetlands of the Egoli Granite grasslands, a degraded and transformed biome within the greater Gauteng province, thus necessitating rehabilitation as part of the overall developmental activities.

As a result, Waterfall City is committed to maintaining and enhancing its natural assets. Ruan Spies, the Environmental Manager at Waterfall City Management Company, says, “a perfect opportunity presented itself that highlights this and we hope our residents will appreciate the efforts made to responsibly manage open spaces – a rare feature in today’s City living.”

The western part of the Kikuyu residential estate, near Old Pretoria Road, faced several challenges brought on by significant stormwater influx coupled with the area’s highly erodible sandy soils, which was further compounded by substantial infestations of invasive plant species that disrupted the wetland’s natural ecosystem.

“To overcome this, we worked together with Balwin Properties to determine the most cost-effective rehabilitation methods. Of course, this meant we had to be quite creative in some instances to find a solution which would underpin sustainability,” says Spies.

We concluded that a combines approach of engineering acumen and using available natural resources on site would be the best course of action. The engineering consisted of gabions, designed to protect the main bridge crossing with rocks to act as a sediment basin where excessive silt is prevented from entering the dam. Excessive silt degrades water quality and negatively impacts aquatic life.

Care had to be taken when it came to invasive tree management. While they undeniably threaten natural resources, their roots did serve a purpose in holding some of the embankments together. Thus, we decided against uprooting the trees in favour of systematic and slower eradication methods, such as cutting and treating the various tree stumps to prevent regrowth. Furthermore, the logistics of removing and disposing of massive amounts of plant debris presented additional costs, and it still left erosion concerns in the upper section of the channel.

“We decided that the best course of action was to repurpose invasive trees as natural building materials. These were used to create a network of lattice fences to protect the embankments from erosion at critical junctures,” adds Spies.

In addition to stabilising the embankments, these wooden fences contribute to the general aesthetics of the wetland by having a more natural look and feel.

“I would like to commend the Balwin Properties team for their efforts. We are glad to have played a small but critical part in rehabilitating the wetlands. As we celebrate World Wetlands Day, this was a project to profile,” says Spies.

As we look forward to other significant environmental days, Waterfall City continues blazing a trail in sustainable urban living. Watch our communication channels for future activities and initiatives celebrating our environmental, reinforcing that a sustainable city is vital to our health and wellbeing.

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