Drivers stuck in long queues due to roadworks face two more weeks of misery.
There was disruption this week as United Utilities (UU) carried out work on Whelley from Monday to Thursday.
A hydrant was installed in a multi-million programme to improve the water supply.
While many may have breathed a sigh of relief when the work ended, it will resume nearby on Monday.
Another hydrant will be installed outside the Earl of Balcarres pub, on Scholes, with a contraflow from Monday to Wednesday.
The work will move to Riverway on August 19, with one lane closed for three days.
The project comes less than two weeks after a lane closure while UU repaired a water main on Whelley.
Resident Greim Phillips said: “This traffic is abhorrent and it can take 30 minutes plus to clear from the town centre to the other side of the roadworks. As I live in Whelley there is no other alternative route unless I want a lengthy diversion through Hindley and Aspull.
“This work should not have been allowed and another route or trunk road should be made between Horwich/Aspull and Wigan.”
A UU spokesman said: “This is the latest phase in our multi-million programme to improve the water supply system in Wigan. We are cleaning miles of water pipes serving around thousands of customers, so they can continue to enjoy fresh, wholesome water from the tap.
Soft bullet-shaped polyurethane foam plugs - known as pigs - will be forced through pipelines to clean them.
It will be done at night with “minimal disruption” to traffic between 11pm and 6am.