Image of tunnel taken by Jackie Allen

A £200,000 project to replace a collapsed sewer in central Cambridge is nearing completion.

Anglian Water was made aware of the broken pipe beneath Pembroke Street last summer and knew the necessary repairs would take some time to complete, causing disruption for the city centre.  

Antony Innes, from Anglian Water, said: “The sewer pipes in this part of the city are buried very deep, meaning repair works often take much longer than in other parts of our region. This sewer in Pembroke Street is over nine metres down and would have needed this key road to be closed for five months while repairs were carried out.  

“Closing the road for this long would have been very disruptive to businesses and the colleges in the area so we explored every option to try avoid this happening. Thankfully working in partnership with the university we were able to find an alternative solution.”  

Rather than the traditional method of digging down to the collapsed section and replacing it, the company decided to ‘cap’ this section off and connect a new sewer to a different part of the network in the university grounds – saving money and avoiding months of disruption.  

Antony continued: “We decided the best way to solve the problem and keep Cambridge city centre open for business was to dig a five metre pit and tunnel across to the sewer pipe. This part of work could only happen with the support of the university and we’re grateful they’ve been so open to this unusual idea.  

“Work started on the tunnel in late December, to try avoid the main term time, and should be completed by the end of January. This week engineers have been crawling in the ‘Great Escape’ style wooden tunnel to connect and lay the new sewer pipe.”