Orange Mayor Reg Kidd said the current outdated water main is being replaced as part of Orange City Council's asset management plan, to ensure households across the city have a reliable water supply.

"The program involves replacing failing infrastructure that is deemed past its life expectancy," Cr Reg Kidd said.

"The old pipes are made of cast iron and are about 100 years old. This strategy aims to avoid the inconvenience and potential damage that is caused when a main breaks.

"Crews have just finished replacing the water main in Icely Road, from Cox Avenue to Autumn Street, and this next stage of the project will stretch along all of Autumn Street."

Just over a kilometre of pipe will be installed in Autumn Street a cost of about $250,000 and will be made out of 150mm UPVC pipe, which is expected to last about 70 years.

Council staff will begin replacing the water main at the Icely Road end of Autumn Street.

The first section of the project will be from Icely Road to Summer Street East, and crews will work a block at a time until they reach Dalton Street.

Once each section of the pipe is in place, each house will be without water for an hour or so as it is connected to the new water main.

Orange City Council Infrastructure Committee Chair Jeff Whitton said crews would try to keep potential inconvenience for residents, businesses and motorists in the area to a minimum.

"Letters are being delivered to residents this week detailing the works and council staff will be talking to businesses and public transport providers in the area to avoid any disruptions," he said.

"Crews will try to avoid road closures, but will have traffic control in the area, and drivers are urged to be aware of the changed traffic conditions."