Utility crews were shocked after finding a sewer had been blocked by growing plants.

Southern Water was alerted to an issue with the levels of wastewater in the pipes near a home in Queenborough which was threatening to cause a leak.

The firm’s maintenance team use sewer monitors spread across the network to alert them when and where blockages are forming.

Strange results were coming from the detector outside the customer’s house, with the level of wastewater in the pipe inexplicably rising and then falling unusually.

Waste proactive control manager, Daniel McElhinney, said: “The system learns how a sewer should behave, taking into account different times of day, when flows are at their highest or lowest, and the impact of rain.

"But if levels stay especially high or low for a long period of time regardless of these factors, the chances are that we have a blockage caused by the likes of wet wipes, nappies and fat, oil or grease from cooking.

“This can cause a nasty fatberg but our monitors were showing that at this address, something was different so a team was sent to investigate.”

It turned out the residents had been spreading bird seed over a manhole in their garden, which was falling into the chamber below through the sides.

Due to the pipe’s warm and dark conditions and because the food was fertilised, it had germinated and flourished, causing plants to grow and slow the flow of wastewater.

Daniel said it was something no one in the team or control room had experienced before.

He added: “We find plenty of weird and wonderful things in sewers from soft toys to mobile phones and even Christmas lights, but this was absolutely a new one on us.

“Usually when a sewer starts getting blocked we go around the neighbourhood giving our standard advice. Only three Ps should go down the loo in pee, poo and paper, and cooking fat should go in the bin.

“But this time the message is please be careful where you feed the birds in your garden. A manhole is not a bird table.”