The proportion of river water samples rated as unacceptable from a human risk perspective has increased from 49% in 2019 to 59% in 2023.
This was according to the City’s Annual Inland Water Quality Report which attributed the figures to an increased frequency of load-shedding, with its effects on sewage pump stations and Wastewater Treatment Works (WWTW), as well as burgeoning poorly serviced informal settlements in many subcatchments and poorly maintained and/or vandalised infrastructure.
The report detailed ongoing efforts and challenges to improving water quality across rivers, wetlands, vleis, and other inland water bodies.
“In line with Cape Town's vision to evolve into a water-sensitive city by 2040, significant initiatives have been undertaken to improve the ecological health of its inland water systems. The report indicates notable progress in managing water quality and strengthening ecosystem resilience amid urban development and climate change pressures,” the City said.
The report found that a major contributor to the degradation of many of the city’s watercourses is contamination with raw sewage.
The study assessed Escherichia coli data for the 2023 reporting period, and compared these with data from the 2019 and 2020 reporting periods.
The proportion of river samples rated as unacceptable from a human risk perspective increased over the assessed reporting periods – 2019, 2020 and 2023 – with data showing increases from 49% unacceptable in 2019 to 59% in the 2023 dataset.
Summary E. coli data for standing water systems suggest that although all the city’s recreational waterbodies periodically posed risks to human health during the 2023 reporting period, they were largely in an acceptable condition, conducive to their safe recreational use.
“The exception to this was Milnerton Lagoon, which was mostly in an unacceptable condition, and its use for recreation would probably have posed risks to human health most of the time.
“The main sources of raw sewage are assumed to stem from the catchment between Blaauwberg Bridge and Otto du Plessis Drive, including overflows from the Koeberg and other sewage pump stations, overflows from the Potsdam WWTW, inflows of polluted stormwater from poorly serviced informal settlements, unmanaged urban areas and backyard dwellings,” the report read.
The City said it was actively implementing several initiatives to improve inland water quality including the Liveable Urban Waterways Programme which focuses on rehabilitating waterways to foster biodiversity, recreational opportunities, and community involvement.
Currently, five projects are under way with additional ones planned.
“A total of R2 billion has been allocated for this 2024/2025 financial year alone for extensions and upgrades at WWTWs and R1 billion towards projects aimed at preventing sewer overflows, such as pump station upgrades, sewer cleaning and replacement programmes,” the City said.
Mayco member for water and sanitation, Zahid Badroodien, appealed to communities to support these efforts by properly disposing of their waste, reporting sewage overflows and protecting water resources.
Cape Times