Bronkhorstspruit Dam sees progress

The Bronkhorstspruit Dam is a vital resource, serving as a water supply, recreational hub and ecological asset. However, this essential dam still faces severe pollution challenges, leading to hypertrophic conditions caused by high levels of nitrates and phosphates.

These pollutants, originating from non-compliant wastewater treatment works, agricultural runoff and industrial effluents, fuel the excessive growth of invasive species like water hyacinth and harmful cyanobacteria.

The overgrowth of aquatic plants in the dam has disrupted recreational activities and threatened aquatic biodiversity. Water hyacinth has been a long-standing issue, forming thick mats on the water’s surface and depleting oxygen levels below.

Similarly, cyanobacteria blooms, another symptom of poor water quality, pose health risks to humans and wildlife.

The community started the Bronkhorstspruit Catchment Management Forum (BCMF) in 2017 to address these challenges.

Since its inception, it has played a key role in combating pollution and protecting the dam’s ecosystem.

One of its most notable achievements was developing a four-point Hyacinth Management Plan, which includes:
• manual removal – Volunteers and workers do regular shoreline clean-ups to remove the hyacinth;

• mechanical control – Using machinery ensures large-scale clearing;

• biocontrol – Using natural predators like insects to suppress the hyacinth growth;

• drone spot-spraying – Authorised by the National Water Act, drones apply herbicides to specific affected areas.

Cara Stokes, the director of the BCMF NPC and an environmental consultant, said the BCMF has fostered partnerships with various non-profit organisations (NPCs), including Baja Care NPC, Dam Estates and Friends of the Bronkies Nature Reserve.

Together, they have raised substantial funds and established dedicated WhatsApp groups to share updates and co-ordinate efforts.

The key initiatives are installing booms to trap floating hyacinth, removing hyacinth from the shoreline, monitoring water quality and implementing biocontrol measures, such as the release of 17 000 bugs by Gerrie Venter in November.

These insects, collected from the Aquavista and Bonamanzi tunnels, were released into a farmer’s dam near the N12 in Botleng to help control the hyacinth growth. While water hyacinth remains a visible symptom of poor water quality, notable progress has been made.

Stokes said infrastructure upgrades are underway, including a R280m upgrade of the Delmas Wastewater Treatment Works (WWTW) by the Victor Khanye Municipality and the installation of a backup pump and power system at the Lanham Pump

Station by the Tshwane Municipality, addressing nearly a decade of sewage spills into the river. These interventions are crucial steps towards improving the overall water quality of the catchment.

However, long-term success will require ongoing efforts in pollution prevention, biocontrol, and catchment rehabilitation, areas which remain the BCMF’s focus.

The BCMF regularly monitors water quality using advanced equipment, such as HANNA handheld meters, to measure electrical conductivity, total dissolved solids and oxygen reduction potential.

These data inform the forum’s management strategies and guide targeted interventions. While the fight against water hyacinth and pollution is far from over, the collaborative efforts of local communities, NPCs and municipalities bring hope for a healthier Bronkhorstspruit Dam.

The road ahead requires sustained action, but the progress achieved thus far is encouraging. For further information or to lend your support, email Cara Stokes at cara@BCMFSA.onmicrosoft.com