Tough measures to limit the amount of water homeowners and businesses can use could become the norm in future years, a water watchdog has warned.

WaterVoice Southern, which represents thousands of customers across the South, said current hosepipe bans could be just the start in terms of water restrictions in the next few decades if major action is not taken by water companies.

Drought orders banning non-essential water use by commercial companies and water rotas which deny homeowners' access to water except at certain times of the day were last used in 1976 but could be introduced on a regular basis if the hot summers continue.

WaterVoice spokesman Andrew Marsh said: "The Government is aiming to build 1.4 million houses in the South-East. If that happens without substantial improvement to the water and sewage infrastructure and if we have an equivalent weather year in 2015 the restrictions would be much worse than they are now.

"While water rotas for households are very unlikely this year it's the sort of thing that could happen in ten years' time if infrastructure is not improved."

He said the region's water companies should try to create something like the ring-main in London, which is a water pipe running almost parallel with the M25 which allows water to be transferred easily from one area to another.

Tackling leaks and looking more seriously at building new reservoirs and desalination plants to transform seawater into drinking water should also be considered.

Yesterday The Argus reported Southern Water and South East Water were introducing more hosepipe bans to cover almost all of Sussex.

Areas affected include Crawley, Horsham, Chichester, Haywards Heath, Burgess Hill, Forest Row and along the Sussex coastal area from Littlehampton to Saltdean, taking in Worthing and Brighton and Hove.

A Southern Water spokeswoman said the company had a 25-year resource plan approved by the Environment Agency and the Department for Environment, Food and Rural Affairs (Defra) which took into account predicted population growth, demand and climate change. Proposals include changing restrictions at Bewl reservoir on the Kent/Sussex boundary so more water can be stored there.

The company has also applied to Defra for an order to allow it to put less water back into the rivers feeding the currently much-depleted Weir Wood reservoir. It also aimed to maintain its low level of leaks, promote efficient use of water and consider other options.

A spokeswoman for South East Water said it had already developed a number of schemes to help in dry periods such as a new pipeline link between reservoirs at Bewl and Darwell, near Robertsbridge. New pipelines and pumping stations were planned, the company was seeking tenders for the construction of a desalination plant and considering proposals for a new reservoir in Sussex.