The Brookside sewage spills were very upsetting for residents, and there were also fears about pollution to Boundary Brook.

We have received the following report from the senior case manager at Thames Water and will publish follow-up correspondence.

Dear Councillor Wilkinson

Thank you for highlighting the repeated external sewer flooding suffered by residents of Brookside. Sewer flooding is always a terrible experience and I fully appreciate residents’ desire for a solution to be put in place given the repeated nature of the problems and the pollution caused as a result.

I would like to reassure you that our investigations into the cause of the flooding are ongoing but our initial findings have not identified a lack of capacity in the sewers. The recent flooding incidents have all been caused by blockages of paper and toilet wipes, rather than hydraulic overload. Hydraulic overload is where the flows in the sewers are higher than they are designed to cope with and usually occurs after heavy rainfall. 

I understand from your email that other residents in Brookside have experienced flooding which they have not reported to us. It is really important that they do report any flooding as soon as possible to our 24 hour Customer Contact Centre on 0800 316 9800. This allows us to investigate and help them as soon as possible and also allows us to build a full history of issues in Brookside, which our operational team then use to justify further investigations or improvements.    

Our operational team have been working hard to identify and resolve the root cause of the blockages. If there is a defect or obstruction in the pipe this would cause items to catch and lead to flows backing up and causing the floods. Our engineer’s inspection of Boundary Brook on 13 July confirmed that floodwater had entered the highways drainage and then into the Brook causing a pollution. As a result he arranged for a full clean and camera survey of the 150mm foul water sewer in Brookside to be completed to check for any obstructions or defects in the line. When our engineer revisited Boundary Brook on 16 July he confirmed that the pollution has stopped but also arranged for our team to complete a clean-up of the Brook on 18 July.     

Our camera team completed the clean and camera survey of the foul sewer in Brookside on 19 July. They cleared scale and debris from the line and left the pipe free-flowing and fully operational. The footage will be shortly viewed by one of our technical specialists to determine if further work is required. I will contact you with the results of the review by 4 August.