A comprehensive environmental assessment of the Braamfontein Spruit and surrounding tributaries in Northern Johannesburg in 2023 and 2024

Abstract

Urban environments are complex systems comprising of interconnected systems consisting of built-up areas, gardens, parks and rivers. These ecosystems provide essential services that support climate resilience, yet urban developments places them under stress, reducing their ability to perform such services. The Braamfontein Spruit in Johannesburg, South Africa, illustrates how urbanisation impacts river health and ecosystem services. This study aimed to assess the spatiotemporal variation in water quality across multiple sites along the Braamfontein Spruit catchment and tributaries, to evaluate the influence of human activity on river health. Sampling was conducted at five sites during three seven-week periods between April 2023 and March 2024. Sites included the two tributaries (Westdene Spruit and Montgomery Spruit0, the Parkview Golf Course, Delta Park, and the Sandton Riverclub Golf Course. Field measurements were taken using a Merck multivariate probe, while biodiversity was assessed using the SASS5 method. Water and sediment samples were collected and analysed for nutrients (sulphate, nitrite, nitrate, phosphate), microbial indicators (E. coli and coliforms), and metals (Fe, Pb, Mn) using standard laboratory methods. Results revealed variable but consistently concerning contamination across sites and seasons. Nutrient and microbial concentrations frequently exceeded South African Department of Water and Sanitation guidelines, with particularly high E. coli and coliform levels at sites along the Braamfontein Spruit. SASS5 biomonitoring scores were low, indicating degraded ecosystems, and negative correlations were served between nutrient and microbial levels and macroinvertebrate richness. These findings highlight the cumulative impacts of urban pollution in Johannesburg’s rivers and underscore the urgent need for improved water quality management in areas of high recreational and domestic use.