The works, at the junction of the high street and Port Street, are necessary to connect a new housing development at the former Carrs Billington site on Port Street to the main sewer system.
Three-way signals will be in place from Monday until February 14, and Dumfries and Galloway Council say drivers should expect some delays during this period.
A second phase of works will require a full road closure of the High Street at the Port Street junction from February 4 until February 22.
The official alternative route will divert traffic along the B721 and the A75, although access to and from Port Street will be available to the west only.
It follows on from the recent closure of Butts Street to allow SGN to carry out gas works.
Cunninghame Housing Association acquired the former Carrs Billington site in March 2017 and are working to build a total of 27 homes at the site.
Commenting on the roadworks, a spokesman for Dumfries and Galloway Council said: “The proposed works follow consideration of potential alternative solutions and approval from Scottish Water, and will be carried out by Ashleigh Construction.”