It’s no secret that Hartbeespoort dam has its challenges. The system has received high nutrient loading water for many decades and has been host to water Hyacinthe since the 1960’s.
Position Statement
The complex nature of a large body of water like the Hartbeespoort Dam is influenced by numerous factors, including wastewater plant pollution, agricultural runoff, leaking infrastructure, invasive weeds, climate extremes, irrigation demands, accumulated nutrients, and toxic sediments, to name a few.
BluePlanet SA, along with many other organizations and contractors, has been part of an integrated strategy to address the short-, medium-, and long-term rehabilitation needs of the Hartbeespoort Dam. Magalies Water was appointed by the Department of Water & Sanitation to oversee the study, management, and innovation required to improve the system. The program consists of multiple intervention strategies, including scientific research, analysis of the dam and its catchment influences, pollution source tracking, water quality amendments, litter traps, and hyacinth management, among others.
In early 2024, Magalies Water sought various solutions to address water quality issues, litter ingress, and hyacinth removal in the system. A formal RFQ process was conducted with multiple respondents, ultimately leading to the awarding of the water augmentation portion of a multi-pronged approach to BluePlanet South Africa. This decision was based on BluePlanet SA’s innovative bioremediation methods, utilizing Nanobubble technology to improve water quality through biological processes.
Given the scale and dynamic nature of the dam, the project was initiated as a pilot program to assess the impact, design requirements, and engineering considerations for full-scale implementation. The BluePlanet Service Level Agreement (SLA) with Magalies Water commenced in October 2023 and concluded in November 2024, when the nanobubble generator located at Ifafi Aquatic Club was handed over to Magalies Water Operations, where it continues to function today.
During both the pre-deployment and SLA periods, extensive testing was conducted at Swartspruit and the Crocodile River inflow into the Hartbeespoort Dam. These tests aimed to evaluate the impact of external pollution sources, the system's inherent sediment and nutrient conditions, and the effectiveness of the interventions. With over 9,000 unique data points sampled, analyzed, and validated by DWS and Magalies SANAS-approved laboratories, a significant body of evidence was gathered to support the interventions and provide deeper insights into the system’s dynamics.
The engineering pilot, deployed in the Swartspruit region of the dam and installed at Ifafi Aquatic Club, was not designed to treat the entire dam. Instead, it served as a study to determine the scale of intervention required for broader water quality improvement and nutrient management. With the successful acquisition of data and completion of operations and reporting, Magalies Water and DWS now have the necessary information to make informed decisions on future interventions.
It is important to recognize that hyacinth coverage levels are influenced by seasonal changes and decades of human impact on the system. The presence of hyacinth is a symptom of a complex nutrient imbalance and cannot be resolved in the short term. While interventions will lead to gradual improvements over time, short- and medium-term hyacinth management still requires ongoing efforts such as harvesting, containment barriers, biological control agents, and, most critically, source pollution control from upstream areas.
At BluePlanet SA, we understand the public’s frustration regarding hyacinth coverage. To provide clarity, here are some key facts:
Hyacinth coverage surges seasonally, as has been the case year after year.
A drastic increase in coverage during the summer months is expected and should not be interpreted as a failure of the medium- and long-term efforts of the project and its stakeholders. Coverage rates must be evaluated objectively, considering dam levels and year-on-year comparisons.
Low rainfall conditions and a subsequent drop in dam levels have hindered the efforts of harvesting contractors, as staff and equipment have been unable to access many shallow and inaccessible areas during the aggressive growth phase of the plant.
The low water levels have also exposed dormant seed banks, allowing for further germination.
Water hyacinth coverage is a symptom of decades of nutrient accumulation combined with seasonal factors. The dam’s eutrophic conditions have persisted for years and will continue to do so for some time.
While nutrient management plays a crucial role in addressing the hyacinth issue, it must be part of a broader strategy that includes both internal and external interventions—from catchment management to sediment-level solutions within the dam itself.
BluePlanet SA supports the biocontrol initiatives led by the Centre for Biological Control and urges public and government entities to provide financial backing for their efforts.
BluePlanet SA’s pilot intervention has demonstrated promising results in nutrient sequestration, organic sediment reduction, and overall water quality improvement within the intervention zones.
The impact observed aligns with global projects that employ similar approaches.
Nanobubble technology addresses water quality at a fundamental level by enhancing both water chemistry and biology, creating the right conditions for natural nutrient management processes to take effect.
BluePlanet SA remains committed to this cause and stands ready to support the Department of Water & Sanitation in future intervention efforts.
For further information contact:
Blueplanet SA
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