Cape Town’s long-troubled Milnerton Lagoon is beginning to show signs of recovery, with early results indicating that years of infrastructure investment and intervention are starting to stabilise one of the city’s most polluted water systems.
For years, the Milnerton Lagoon and surrounding Diep River catchment have been under pressure from pollution, ageing infrastructure and repeated sewage overflows. The issue has drawn sustained criticism from residents, environmental groups and businesses, with concerns ranging from water quality and public health to long-term ecological damage.
Now, according to the City of Cape Town, there are measurable signs that conditions are improving.
At a public meeting held on 25th March, officials outlined progress made through a coordinated programme of maintenance, upgrades and system redesign. The focus has been on improving flow within the catchment, reducing contamination and strengthening the resilience of critical infrastructure.
Mayoral Committee Member for Water and Sanitation, Zahid Badroodien, said the City is beginning to see the benefits of sustained investment. “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.
City data supports this shift. Sewer blockages across the catchment have declined from 4,270 recorded incidents in October last year to 3,489 by February. While still high, the downward trend suggests that preventative maintenance and pipe rehabilitation are beginning to reduce system failures and limit spillages into the lagoon.
Air quality monitoring has also shown a marked improvement. Hydrogen sulphide-related odour incidents, which have long affected nearby communities, dropped from 1,397 recorded exceedances between February and December last year to just 10 between January and late March this year. During this period, the World Health Organization’s daily guideline for exposure was not exceeded.
A significant portion of the recovery effort is centred on the Potsdam Wastewater Treatment Works, one of the largest treatment facilities serving the area. Upgrades to the plant include advanced ultrafiltration and dewatering systems, which are already operational or in testing phases. A membrane bioreactor system is expected to be commissioned later this year, further improving effluent quality and nutrient removal.
Beyond the treatment works, infrastructure upgrades are being rolled out across the broader network. Nearly 4 kilometres of sewer pipeline have been rehabilitated in areas including Montague Gardens, Milnerton and Century City, helping to extend the lifespan of ageing systems.
In addition, all 56 pump stations in the lower Diep River system are now connected to a real-time telemetry network, allowing for faster detection of faults and quicker response times to prevent overflows.
Looking ahead, the next phase of the project includes dredging of the lagoon to improve water flow and reduce sediment build-up. The City is also preparing to launch a saline water pilot project, which will introduce seawater into the system to help dilute pollutants and improve circulation.
Emerging technologies such as nanobubble systems and microbial treatments are also being tested as part of efforts to reduce sludge, odours and harmful bacteria.
While these developments mark a significant turning point, officials caution that the recovery of the lagoon will depend on sustained investment, consistent maintenance and ongoing monitoring. For residents who have lived with the impact of pollution for years, the improvements offer cautious optimism, but the long-term outcome will depend on whether these gains can be maintained.
Source: IOL – Murray Swart
