Roll up your hosepipes for the big turn-off

There may be blizzards in the north, but much of the UK is so gripped by drought that, from today, millions of people will be subject to draconian restrictions on their use of water

Twenty million people in the South and East of England awoke to the first day of a hosepipe ban this morning, as emergency drought measures imposed by seven water companies came into effect. From midnight, people in the South and East risk fines of up to £1,000 for using a hose for all but a few exempted activities.

Two consecutive dry winters have taken their toll on the South's reservoirs and groundwater levels, leading to severe drought conditions that are expected to last all of spring and summer. It may be many months before gardeners can turn the sprinklers back on.

Although rain is now falling across much of the South-east – and other parts of the country have even seen heavy snow – the Environment Agency has warned that it is now unlikely that groundwater levels can be replenished in time to avoid a long-lasting drought that will impact on both people and the environment.

For two years in some parts of the country, reservoirs and the underground water sources that supply the country's water have not been replenishing fast enough to keep up with demand. In Bewl in Kent and Ardingly in West Sussex reservoirs have had to be refilled from already-depleted rivers. Water levels are below normal at most of the UK's reservoirs and some are reported to be at half-capacity.

Thames Water, Anglian Water, South East Water, Veolia Water Central and South East – which service London and much of the South-east – and Sutton and East Surrey Water, are all imposing "temporary-use" bans on hosepipes. The ban applies only to domestic activity, meaning that hoses used for farming, commercial cleaning and watering sports grounds for national and international events will not be subject to restrictions.

Water companies insist that the ban will be "self-policing", but penalties can still be enforced under law and neighbours will be able to report violations to their water company.

In some areas, "yellow-card" letters will be sent out to people known to be defying the ban, followed by a visit from officials before a prosecution will be sought. A third of people responding to a survey on HosepipeBan.org.uk, a web forum, said they would report a neighbour using a hose. In another survey on the site, another third of people said they would defy the ban altogether.

Richard Aylard, Thames Water's sustainability director, said that a ban now would limit the likelihood of further restrictions in the future and urged customers to co-operate. "After two such dry years we have to prioritise the most important uses of water. That means keeping everyone's kitchen and bathroom taps supplied has to take precedence over manicured lawns," he said.

Gardeners are already investing in equipment to help them through what may be a long dry summer. B&Q reported that sales of water butts were up 196 per cent compared with this time last year. Garden centres are expecting increased interest in drought-resistant plants such as lavender and bergenia.

The ban could be adopted by other water areas if the drought continues. This week, drought conditions spread to parts of Yorkshire, and Wales, the South-west and the Midlands are also under threat. The last time a widespread hosepipe ban came into force, in 2006, it lasted until January of the following year in some areas. It has been this dry only four times in the past 101 years. This year's drought has been exacerbated by the sunniest March since 1929, but it is still unclear how bad this year will be.

While the impact on domestic water supplies is likely to be limited to the hosepipe ban, the impact on the agriculture and the environment could be much more severe. Fruit, vegetable and salad crops in the South of England could be severely affected if drought restrictions on irrigation are enforced.

In rivers, ponds and lakes, levels are becoming so low that a number of wetland species may die or be unable to breed, while many water sources may have dried up before aquatic insects, a key part of wetland ecosystems, have fully formed.

Ban basics: What those in the no-hose zone need to know

What can you now not do with a hosepipe?

Water or sprinkle your garden (drip or trickle irrigation systems are allowed), clean private vehicles, water plants, fill pools or ponds, clean windows, patios or walls, or other domestic recreational uses.

If I can't use a hosepipe, what can I use?

Wash your car with a bucket of water and sponge, or take it to a commercial car wash. You may water your grass and plants with a watering can. You can even fill a paddling pool or swimming pool using buckets of water.

Which companies have bans?

Southern Water; South East Water; Thames Water; Anglia Water; Sutton and East Surrey; Veolia Water Central; and Veolia South East. About eight million homes and 20 million people are affected.

Will prohibition work?

Sixty-five per cent of people plan to observe the ban, and 36 per cent would report neighbours flouting it.

Olivia Lee