Some Christchurch roads may lay un-repaired for up to 30 years.

It's been revealed repairs on some blocks of road will remain incomplete when SCIRT (Stronger Christchurch Infrastructure Rebuild Team) steps away from Christchurch at the end of the year.

These roads will instead be fixed by the council in a timeframe which spans about three decades.

Many of these areas will be around the eastern suburbs.

SCIRT CEO Ian Campbell pointed out that it's always anticipated this, and by default the council will take on and prioritise any work which isn't finished.

"The challenge for the council is to do that in an even way so that everybody's getting the same sort of improvement over a period of time," Campbell said

"They consider engineering factors, how badly they're broken, how critical is it, what's the cost to the council to maintain the damaged infrastructure before it gets repaired."

"I don't think thirty years is the time we should put on that, but that's for the council to decide."

Councillor Phil Clearwater said the council is committed to finishing the work, but it's hard to give specific timeframes.

"But we have to be really careful not to over-promise or over-budget because in the end that's unfair on people to raise expectations and also all of the work has to be achievable and has to be paid for," he said.