They advise that the work may create a disturbance to the water distribution system in the North West area of Fergus.
It may become discoloured during and after the work.
It is caused from iron and manganese that are naturally occuring in the groundwater.
When the watermains are flushed, minerals that have settled in the system may become stirred up.
They urge residents to turn on the cold water tap nearest the water meter and allow it to flush slowly for several minutes until it runs clear.
If discolouration continues after 24 hours they urge to contact the Infrastructure Services number at (519) 846-9691 ext. 905.