Manx Gas is asking motorists to be patient as work continues in a busy area of Douglas.
Engineers are replacing mains in Victoria Road, and the company says the project is unlikely to be finished before next Monday (November 7).
There are traffic lights in the area which will remain in place until the work is completed.
Engineering director Robert Gardner is advising motorists to use a different route if possible, and is apologising for any inconvenience.
TT 2026: Three races due to take place today
Supersport, Sportsbike and Senior Races all on the schedule
Police say they've seen a spike in drug offences on the IOM this week
Possession and production among the key crimes being picked up
German TT visitors fined after flouting speed limit
Pair spotted doing 95mph in 50mph zone
£50K prize pot to be split between sidecar competitors
Follows cancellation of class at TT 2026
Southern 100 planning to run classic sidecars for 2026
It's after modern machines were excluded from July event