The £9m project will install a pipeline between Crooms Hill, Greenwich and Ordnance Crescent, adjacent to the O2 stadium on the Greenwich Peninsular.
The programme of works is a key element of Phase Two of the construction of new water infrastructure between Deptford Water Treatment Works (WTW) and the Greenwich Peninsular due to complete in March 2024.
This will help Thames Water meet water demand for ongoing and future development.
Barhale was also responsible for the completion of Phase One – the Deptford to Greenwich Main – which ran from Broadway Fields near the Stephen Lawrence Centre along Greenwich High Road to Crooms Hill.
The new main will connect to an existing DN800 water main at Crooms Hill before crossing Greenwich Park.
It will be the largest construction project to be undertaken in the park since the 2012 London Olympics.
Barhale contracts manager James McKenzie, said: “This part of south east London is seeing a lot of development activity at the moment and that is only likely to continue as cross-river access improves thanks to the new Riverlinx project
“The new main between Crooms Hill and the Peninsular will be another important step towards meeting increased demand and building greater resilience in the network.