Canberrans could face stage-one water restrictions by the end of 2020 if current dry conditions continue.
The forecast from Icon Water came as dam levels in the ACT dropped below 50 per cent on Thursday.
It's the first time water levels in the ACT have fallen to that level since the Millennium Drought in 2002.
However, Icon Water's managing director, Ray Hezkial, said the ACT was better equipped to handle falling water levels than it was 17 years ago.
"Back in 2002 when we had water restrictions we had a storage capacity in dams of 115 gigalitres, and the annual water consumption was at 70 gigalitres," Mr Hezkial said.
"In 2019, as it stands our total capacity is 140 gigalitres and the consumption has dropped to 50 gigalitres a year."
During the summer period, Canberra's dams are expected to fall by 1 million litres.
Dams in the ACT have not been at full capacity since 2017.
Despite Cotter Dam's capacity being increased by 30 per cent as part of recent upgrades, drier than average conditions have led to falling water levels.
"If you look at the October average rainfall, it's 65 millimetres, and this year we only had 27 in the month," Mr Hezkial said.
"It gives an indication of how much the flow into the dams drops off rapidly, and even though the storage levels are secure, we're asking the community to try even harder at conserving water."
While water restrictions were enacted in NSW once the state's dam levels dropped below 50 per cent, Mr Hezkial said water restrictions were not likely to be enacted in the ACT just yet.
He said water restrictions may come into effect in the second half of 2020 if there is no significant rainfall or water consumption doesn't decrease.
"If circumstances change, or the rate of consumption doesn't reduce to the levels expected, we may review that decision and impose water restrictions sooner if needed," he said.
The Bureau of Meteorology said no major rainfall is expected until at least February.
While dam levels continue to drop, Mr Hezkial said water conservation measures put into effect in 2010 had helped reduce consumption levels across Canberra.
Those conservation measures included restricting the use of sprinklers and irrigation systems to between 6pm and 9am during hotter months, and hoses being fitted with trigger nozzles.
"The Millennium Drought really changed the psyche of the Canberra community [in terms] of how precious water is, and ... permanent water measures have now become normal," Mr Hezkial said.
"We've been aided by better technology and more efficient appliances, but by far and large the community's attitude to conserving water has changed since the Millennium Drought.
"The challenge is now we can try even harder, and the reason that's important is it allows us to stave off restrictions."