The burst pipe was nearly 46 years old and it was impossible to estimate how much water had been lost, according to Canberra's water utility. And there will be no upgrades to water pipes in Wanniassa this year, it confirmed.

Icon Water says the burst water main on Wheeler Crescent was reported at 6.27pm on Wednesday.

"As the custodians of drinking water, a precious resource, we make every effort to attend as quickly as possible and to safely isolate supply should a burst occur," a spokesperson said.

"In this case, the water main was isolated at 7.05 pm. The water main was repaired and supply was reinstated at 11.55 pm, less than six hours from the time the first report came in."

The 150-millimetre water supply main was installed in September, 1973.

"Generally, it is difficult to pinpoint the cause of failure as there could be a range of reasons such as ground movement or fluctuations in pressure. Water main failure rate is relatively higher in winter due to the ground movement that is often caused by dry conditions," the spokesperson said.

Comments on social media about the Wanniassa geyser suggested there had been other significant water problems in the same area in recent times.

Icon Water said in response: "Our records show that the failure rate in Wanniassa is not high in relation to other parts of the network".

"To minimise the risk of these types of events across our 3200-kilometre water network, Icon Water invests in a regular water mains renewal program to address older parts of our network and areas that have recorded a higher water main failure rate."

Nearly seven kilometres of mains were scheduled for renewal this year - but not in Wanniassa.

Just over 8 per cent of the 6803 kilometres of pipes to be upgraded would be just along Canberra's Golden Mile, Mugga Way in Red Hill (567m).

The suburbs to get the upgraded pipes this year were Barton (756m), Cook (426m), Forrest (789m) , Griffith (1378m), Holder (476m), Kingston (1730m), Pearce (261m), Pialligo (156m), Red Hill (567m) and Yarralumla (266m).