Buses and motorists were unable to pass though the flooded road, with advice to use alternative routes near Witham Way.
As of 2.30pm the water had been drained, but traffic was still being diverted down Fulbridge Road, past Paston Church and on to Hallfields Lane.
Anglian Water confirmed engineers had been on-site to fix the problem after reports of a burst water main.
A resident told Peterborough Matters: “Cars and buses are having to turn around due to the flooded road – it's quite bad and this has been ongoing since about 9:30am this morning.”
A spokesperson for Anglian Water apologised for the inconvenience and said this morning: “We are really sorry, but some customers in Gunthorpe, Paston Ridings and surrounding areas may be experiencing low pressure or no water pressure at all.
“We have identified a burst water main in the area and we are working hard to get it fixed. We estimate the supplies should restore back to normal by 6pm, but we will keep our customers updated.
“We apologise for the inconvenience and thank everyone for their patience.”