Home owners and businesses are expecting to hear any day whether bans on all non-essential uses of water are to be brought in.

Sutton and East Surrey Water has already been given permission to bring in a ban, which will affect Gatwick and change the way terminal buildings and planes are kept clean.

Any day now Southern Water and South East Water will find out whether they can impose similar bans, affecting all of Sussex.

Despite recent showers reservoirs are still dangerously low. At Weir Wood Reservoir in Forest Row, East Sussex, the banks are littered with boats that would usually be on the water at this time of year.

The Gatwick ban, which also affects parts of Crawley and Mid Sussex, comes into effect on Saturday and was authorised by environment minister Ian Pearson.

It is the next step up from a hosepipe ban and bars companies from using mains water supplies to clean buses, airliners, trains and buildings.

It will affect all companies working at Gatwick, which employs 25,000 people.

Airlines will only be able to wash aircraft using water brought in on tankers. Hoses or sprinkler systems drawing water from the mains will be banned.

The same restrictions will apply to the washing of windows at terminal buildings.

Ornamental fountains will be banned along with automatic toilet cisterns in areas of the airport that are not used frequently.

Mike Hegarty, operations director at Sutton and East Surrey Water, said he was relieved Mr Pearson had allowed him to impose the ban.

He said: "The water resource position remains unchanged following disappointing rainfall in the past two months.

"The priority now is to ensure available resources are able to meet essential demand this summer and autumn.

"It is important that everyone understands the seriousness of the current drought in the South-East.

"We are phasing in the newly-permitted restrictions. The potential large uses of water will be banned from May 27.

"A small number of permitted restrictions will not be introduced at this stage as they do not represent significant uses of water.

"Whether or not restrictions are extended to these uses will depend on the reduction in demand for water during the coming weeks."

Mr Pearson said: "The drought in the South-East remains serious. There have been misleading and unhelpful reports suggesting recent rainfall has somehow solved the problem. It hasn't.

"Reservoir levels may have risen, but river flows and groundwater levels are worryingly low."

A BAA Gatwick spokeswoman said: "Gatwick already has in place water consumption targets and we will continue to monitor our usage and consumption levels.

"We will be working with the water company on a range of activities and to take action where appropriate to meet the order."