The water company said it still had a live investigation into which firm dumped concrete into the sewer system.
Parts of North End Road in Fulham will now be closed for six weeks while Cappagh’s team excavate the area and use specialist tools to break down the concrete.
Once it has been removed, they will replace the affected sewer sections.
Thames first identified the concrete blocking the pipework last summer. Since then, it has been forced to use tankers to transport daily pump-outs of the sewers to prevent nearby homes and businesses from flooding.
Thames Water confirmed it is currently investigating the incident and plans to progress a claim to recover all costs for the mitigation measures that have been in place, and repair of the pipework.
Jamie Keech, area network manager for North West London at Thames Water, said: “It’s very frustrating to see our customers suffer because of this mindless abuse of our network. This is not the first time we’ve seen damage caused by people pouring concrete into our sewers, which takes a great amount of resource to resolve.
“We are working to find those who have caused this disruption to local residents and businesses, and we’d like our customers to know we will work seven days a week with our contractors and the local authority to get the road re-opened again as safely and quickly as possible.”