Since January, the firm’s engineers have been laying 1.3km of water pipes along West Heath Road in a £750,000 scheme.
Lane closures were introduced on the roundabout on Tuesday June 13 as the project reached its next stage. SEW said this stage would take around four weeks to finish.
Matthew Cooper, project manager at SEW, said: “Our work in West Heath Road has gone well.
“We want to thank local residents and motorists for their patience and co-operation.
“To allow us to lay our new pipe along the roundabout, we need to have traffic lights in place to keep everyone safe.
“We appreciate roadworks can be frustrating. We are working with the local highways department to keep traffic flowing through the area and keep disruption to a minimum.
“I would like to apologise for the disruption this work will cause.
"I hope motorists and the local community understand the long-term benefits this scheme will deliver.”
Once works are complete on the roundabout, engineers will lay a small section of pipe at the entrance to Fleet Road.