The Water Services Association, which represents nine of the ten large drinking-water and sewage groups, was briefing journalists to pre-empt a government report on future water use being published today.
The association claims that reducing mains leakage and attempting to persuade the public to use water more carefully is no longer enough to guarantee freedom from shortages. A new "twin-track approach" is needed, in which water resources are boosted, Severn Trent's managing director, Brian Duckworth, said.
But large new reservoirs and the pipes and pumps needed to service them cost tens of millions of pounds, while the water companies are under strong political pressure to hold down bills to customers - which have risen much faster than inflation in the years since privatisation.
"We want to start a debate," a spokesman for the Water Services Association said. "Climate change is something the industry has to take on board, and we need to think long-term."
In the meantime, the contents of today's Government report was publicised by Friends of the Earth and the Labour Party, to whom it had been leaked. It was revealed that ministers were also taking global warming seriously, and want the water companies to reassess supply and demand in a warmer Britain.
The Government has no proposals for radical new measures. But, after several years of drought and restrictions, it says there is a need for "greater dialogue between water companies and their customers on the balance to be struck between higher security of supply and higher costs".
Household water use has been rising by 1 per cent per year as people have become more affluent. In 1961 the average person used 85 litres a day. Today, with more bathing and showering, use of dishwashers and washing machines and more garden watering, that figure has nearly doubled.
Throughout the Nineties the Government has been in favour of "demand management", which means persuading customers to use less. That is why it has backed the spread of water meters, but it has been criticised for doing little concrete to encourage water efficiency. For example, showers - which use far less water than baths - are not mandatory in new homes.
At the moment much of England has a hidden drought, with water tables in five aquifers dotted around the country at record low levels. Yorkshire Water announced yesterday that all its water restrictions would finally be lifted next month, but there are also bans in parts of Southern's and nearly all of North West's areas.
Until this year the companies claimed that they and their customers were the victims of freakishly low rainfall, of the kind that only happened once in 100 years or more. But now they are saying this could be an early sign of man-made climate change. Rainfall has been below average for more than two years.
At the moment, supercomputer simulations of global warming over the next 50 years predict that Britain's total rainfall will increase. But summers across most of England and Wales are forecast to be longer, hotter and drier, sending demand soaring and creating the need for more to be collected and stored in winter.Reuse content