Taxi drivers and crop growers are among large sections of people legally allowed to ignore hosepipe bans in their areas.
Millions of Britons are living under hosepipe bans as fears grow of drought in the worst-affected areas.
The heatwave that has hit the UK this year has broken records, including eight days at or above 34C in a year. And last month was the hottest on record for England.
Anglian Water, which serves most of the East of England, brought in a ban on Saturday for its more than 5 million customers.
Much of Kent, Hampshire and the Isle of Wight are also under hosepipe bans, as are large areas of Bedfordshire, Berkshire, Buckinghamshire, Hertfordshire and Surrey.
There are also bans in mid-Devon and parts of East Devon, and some parts of London and Essex. Cambridge Water has introduced one for the first time in three decades.
Under the rules, most customers may not fill up swimming or paddling pools, or water their garden or clean their car. Anyone breaching an official ban can be fined up to £1,000.
But there are many exceptions, often based on additional needs or using water to protect people or animals.
Water companies typically exempt people on their priority-services register who cannot adjust because of a health condition or disability, Blue Badge holders and people who need to protect human health or safety.
Using water for animal welfare, including pets, livestock and fish is also allowed.
These are other exemptions given by South West Water:
Gardeners may also water trees, hedges and saplings planted in the previous planting season, where a watering can is not feasible; turf laid within 28 days; plants for 14 days after purchase, and food crops grown at home or at a private allotment, where using a watering can is not feasible.
A pool, paddling pool or hot tub may be filled with a hosepipe if it is needed for medical or veterinary treatment or animal welfare; it’s for medical or therapeutic use; it’s under construction and needs to be filled as part of construction.
If a pond or pool is used as part of a recognised religious practice it’s also exempt.
Hosepipes may be used if the water comes from a butt.
Anyone cleaning a home’s exterior, such as windows, paths, patios and driveways, may use a hosepipe if part of a professional service or business.
Car owners may use a hosepipe if they use a low water-use appliance such as a pressure washer; to clean a vehicle as part of a private business, for example a car wash; the vehicle is used for public services, business purposes or transporting goods, or if the vehicle is a taxi, commercial vehicle or goods vehicle.
Caravan or motorhome owners may use hosepipes to fill a tank if needed for essential washing, cooking and sanitation.
On boats, a hosepipe may be used by anyone cleaning it as part of a business or professional service; anyone cleaning it to prevent the spread of non-native species or to remove graffiti or if the boat is used for commercial activity or public services.
Commercial growers of crops, fruit, vegetables and plants cultivated for sale are exempt from the ban, as are national plant collections and temporary flower or garden displays that are public.
An irrigation system that drips or trickles, with a time- and pressure-reducing valve and that delivers water directly to soil may be used.
Sports pitches are exempt provided watering is done outside the peak hours of 8am-10am and 5pm-9pm.
Even where exceptions apply, people are still asked to be careful with water “to help safeguard essential supplies”.
