23 Jan Fenning Street Sinkhole – update from the Council as at 21 January

A more comprehensive update has been sent by Councillors this last week to provide reassurance about the sinkhole that opened up in Fenning Street a few weeks ago. Cllr Emily Hickson relayed a statement from Council officers, dated 21 January 2025:

“Weekly meetings with the Site Operators, Utilities companies and the council continue following the appearance of a sink hole in Fenning Street, SE1 on the 6 January.  

The exact cause of the sink hole remains under investigation. Mace completed the construction of basement over a year ago. Until the 5 January ’25, the basement was dry. The hole appeared after material and ground water entered their basement at basement levels 3 and 4. The construction of the basement at the level 4 created a ‘pocket’ in the clay, which was breached most likely by the ground water. Material from under the carriageway entered the fourth basement level of the construction site. This created a void beneath the roadway which then collapsed into the hole. The volume of material in the basement is equivalent to the material lost from the highway.

Mace are presently, sealing the basement, which when completed, will allow them to reinstate the highway. In addition to the damage to the roadway the collapse damaged electrical supply cables to the construction site and a water main. The electrical cables have been isolated and rerouted. The water main was found to be redundant and has been disconnected. Before remedial work could be commenced additional ground surveys were completed to ensure there are no more voids or contributory factors. The sewer network has also been checked and found to be operating correctly. 

The council engineering services are in close liaison with the team from Mace and have approved their method statements for the repairs. The work is likely to take a number of weeks to complete.  To monitor progress there is a weekly meeting between the site operators, the utilities companies and council representatives. Work at the construction site continues with the hole being continually monitored 7 days a week.

We will provide regular updates to all parties on the progress of the investigation and work to repair the road and basement areas.”