Gas and water main works have begun in Newtown
Major water and gas mains work began in Newtown this week.
The work to the utilities has been on hold to allow the town's bypass to open and cause less disruption to motorists.
Delays are expected along New Road and Llanidloes Road in the town because of temporary traffic lights and some diversions will be in place
The entrance lane on Park Street junction will be temporarily closed from 5-16 August as part of the works.
A spokesman for Powys County Council, said: "Hafren Dyfrdwy and Wales and West Utilities are carrying out major water mains and gas mains renewal works in Newtown that have been on hold for some considerable time.
"This was due to the significant disruption that would have occurred without the bypass being in place.
"These works are taking place over the school summer holidays due to the immediate proximity of several schools."
The Newtown bypass opened in February.