Early action to save water now can prevent the need for extreme measures like standpipes, Environment Minister Ian Pearson has told MPs.
A drought order could be used to ban many activities
Mr Pearson is heading the government's efforts on the water shortages which have forced England and Wales' first drought order in 11 years.
He told the Commons he was considering similar curbs in two other areas and urged everybody to "do their bit".
Water companies also needed to "up their game" in plugging leaks, he said.
Millions of people are already subject to hosepipe and sprinkler bans and a drought order has been granted to Sutton and East Surrey Water.
Southern Water and Mid-Kent Water have also requested drought orders.
The Environment Agency has warned that the South East could be on course for its worst drought conditions for a century.
They say there is a risk that standpipes might be needed in London if water levels are low this autumn after an exceptionally hot summer.
Mr Pearson said the Metereological Office was forecasting average rainfalls this summer and he said he could not confirm claims that some areas were 100 days away from needing standpipes.
"It would be unwise to say we're going to have standpipes in a certain number of days because that is simply not the case as we stand today," he said.
Urging people in the South East to use water wisely, he said they should not leave the tap running when they brushed their teeth and should ensure their washing machines had full loads.
"It's surely right to make take early prompt action now and the message to consumers in the South East now to use water responsibly can, I think, make sure we don't need to take more extreme measures at a later stage," he said.
The Conservatives put down an urgent question in the Commons about the water shortages.
Shadow environment secretary Peter Ainsworth said: "We don't blame the government for the weather but we and the public will certainly hold them to account if they fail to take action to avert the worst effects of water shortages this year and in the future."
He demanded to know whether Labour still opposed compulsory water metering and what ministers were doing to make water companies plug leaks.
And he said it would be the "height of folly" for the government to press ahead with its plans for millions of new homes in the South East unless the infrastructure was in place to supply water to them.
Liberal Democrat environment spokesman Chris Huhne asked: "In the light of potential climate change and what appears to be a recurring pattern of extremely dry summers in the south-east, isn't it time to reassess the extra five reservoirs already planned for the south-east?"
Mr Huhne said the government and water companies needed to take more action over leaks, were running at 27% at some cases.
Mr Pearson said there were too many leaks but noted that Sutton and East Surrey Water, which is subject to a drought order, had met their targets for cutting leaks.
He said 70% of households now had water meters but the government did not want to force metering on people - "certainly not unless there is a water scarcity situation".
Nor did he think families facing the drought orders should get discounts from the water companies.
On the housing fears, he said there was a clear difference between droughts in the short-term and ensuring water needs were met in the long-term.
The idea of a "national grid" for water was a "non-starter", said Mr Pearson. It would take a lot of energy to pump water around the system and excavations would be needed across the country to install pipes.