Wessex Water will replace the water main within the B3105 (New Terrace) in Staverton with plastic pipes.
The work is set to begin on Wednesday 26 July and last for 21 weeks – finishing in early December.
Wessex Water has warned that the project will impact travel to and from Trowbridge, Holt, Bradford on Avon and Hilperton.
They added that the new main would improve water quality for the local community.