Northumbrian Water and its partner, Esh-MWH, have been working on the complex project in the Deepdale area of Barnard Castle, on the project to replace 160 metres of water pipe.
This included a temporary pipe being laid across Deepdale Aquaduct to maintain customers′ supplies throughout the work.
The project was extended in November to allow work to take place on a neighbouring pipe, to reduce the likelihood of future disruption.
With work now complete, traffic management will be removed and Deepdale Aquaduct re-opened to pedestrians, and the project team will have left site by Friday, February 15.
Gary Cassells, Project Manager at Northumbrian Water, said: "This has been a complex, but very important project, during which we have kept in close contact with customers in the area. We thank them all for their patience and their understanding that this has been vital work to safeguard water supplies in Teesdale.
"This was a very old pipe - around 100 years old - and the work will make the supplies to the area more resilient for the future.
"During the course of the project, the team have had the pleasure of working with a number of individuals and community groups, including Brightwoods Forest School. We have been made to feel a part of the community and it has been great to be able to give some things back at a time when our work has been so prominent in the area."