Milnerton Lagoon restoration shows promising results as upgrades take effect
Infrastructure upgrades lead to major improvements in Milnerton Lagoon's health.
Image: Unknown
Cape Town’s long-running effort to restore the Milnerton Lagoon is showing early signs of improvement, with the City saying key infrastructure upgrades are starting to reduce pollution and stabilise the system.
The latest progress comes amid longstanding public concern over pollution and deteriorating water quality in the lagoon and surrounding waterways.
At a public meeting on March 25, the City of Cape Town updated residents on its intervention programme, outlining a series of measures aimed at improving water flow, reducing contamination and strengthening infrastructure across the Diep River catchment.
Mayoral Committee Member for Water and Sanitation, Zahid Badroodien, said early gains were now becoming visible.
“We are beginning to see the results of our investments. Fewer blockages and reduced odours are just some of the benefits. These interventions are building a more resilient system for the long term,” he said.
The lagoon has long faced pollution challenges, with residents and environmental groups raising concerns about its condition. City data now indicates a shift, with sewer blockages in the catchment dropping from 4 270 in October 2024 to 3 489 by February 2026. Officials say preventative maintenance, pipe rehabilitation and system upgrades are helping to reduce failures and limit spillages.
Air quality monitoring also shows a sharp decline in hydrogen sulphide-related odour incidents, from 1 397 recorded exceedances between February and December 2025 to just 10 between January and late March this year. The World Health Organization’s daily health guideline was not exceeded during the monitoring period.
A central focus of the recovery plan is large-scale infrastructure investment, including upgrades to sewer networks, pump stations and treatment facilities. At the Potsdam Wastewater Treatment Works, key components such as ultrafiltration and dewatering are already operational or in trial phases. A membrane bioreactor system, expected to be commissioned in November, is set to further improve effluent quality and nutrient removal.
Across the catchment, rehabilitation work has covered nearly 4km of sewer pipeline in areas including Montague Gardens, Milnerton and Century City, helping to extend the lifespan of ageing infrastructure. All 56 pump stations in the lower Diep River system are now monitored in real time via telemetry, allowing faster response to faults.
Etienne Hugo (Director: Distribution Services at the Water and Sanitation Directorate) outlines ongoing sewer and pump station upgrades supporting the restoration of the Milnerton Lagoon at a public meeting in Milnerton.
Image: Supplied
Upgrades at key pump stations are also under way, with improvements at Koeberg Road helping to contain overflows, while work at Dunoon and Table View East is progressing toward completion by June. The Phoenix pump station remains in the design phase, with construction anticipated to begin in 2028.
The next phase of work will include dredging of the lagoon, with a tender currently under evaluation and construction expected to begin in June. The project will reshape sandbanks, create a defined channel and improve flushing to reduce stagnation.
In addition, a saline water pilot project is set to launch in September, introducing seawater into the system to dilute pollutants and improve flow. The City is also testing emerging technologies, including nanobubble systems and microbial treatments, aimed at reducing sludge build-up, odours and harmful bacteria.
“These measures are already making a difference. As major interventions move into implementation, we are entering a critical phase that will further improve the health of the Milnerton Lagoon and the surrounding catchment,” said Badroodien.
While early improvements are evident, the long-term success of the clean-up will depend on sustained investment, effective maintenance and continued monitoring.