The City of Harare has raised alarm over increasing sewer blockages across the capital, caused by illegal dumping of huge quantities of solid waste being dumped by residents.

In an interview, Harare department of water Engineer Simon Muserere said 60% of sewer system problems are caused by residents with only 40% stemming from wear and tear or structural issues.

He said in Harare the council used to receive over four tonnes of sand per day at our sewage treatment plants which meant sewer lines had a self-cleansing velocity.

Follow us on WhatsApp | LinkedIn for the latest headlines

"Now, that self-cleansing velocity is lost. Instead, between three and four tonnes of sand are accumulating in the pipelines," he said.

Muserere said the sand and debris including rags, kitchen utensils and building waste mainly come from domestic areas and careless construction practices.

He said the waste is now affecting even low-density suburbs, traditionally less impacted by sewer blockages.

"This is a major concern as we have seen a significant rise in blockages across all areas of the city," he said.

Muserere highlighted that the city has also been forced to deploy high-velocity sewer clearing machines and conduct expensive excavations to unblock lines interventions that are costly and unsustainable.

He said residents should also consider the issue of water rationing, which has resulted in inadequate flushing.

He said residents should use larger buckets to flush toilets when water is unavailable.

"When you use a very small tin, it might clear your toilet, but the load remains in the pipeline. A larger bucket helps push waste through to the treatment plant," Muserere said.

He urged residents to play their part to reduce user-related blockages.

"If we cut down the 60% caused by residents, we can focus our limited resources on fixing structural issues and avoid overstraining the city's budget," said Muserere.