The UK's first hosepipe ban of the year comes in force on Friday, August 5, for Southern Water customers across Hampshire and the Isle of Wight.
The Temporary Use Ban has been put in place following the region's driest year for a century.
The company, which handles drinking water and wastewater in parts of the county, says the ban is needed to "urgently reduce" demand on the River Test and River Itchen.
However, depending on where you live in Hampshire, Southern Water may only deal with your wastewater meaning you might not be affected by the ban at all.
The majority of homes which will come under the ban are on the Isle of Wight and parts of south and mid Hampshire, while some homes in Berkshire will also be required to reduce their water usage.
Dr Alison Hoyle, Director of Risk & Compliance at Southern Water, said: "We haven't taken this decision lightly and we know the Temporary Use Ban will have an impact on our customers.
"We're working with the Environment Agency to ensure that we act responsibly to protect our environment.
"We're asking everyone in Hampshire and the Isle of Wight to do their bit by supporting these measures and only use the water that they need.
"We're experiencing one of the driest years on record for over a century and we've seen record temperatures.
"River flows are approximately 25% lower than they should be for July, which is equivalent to losing more than 25 million bathtubs of water.
"We're asking our customers to help protect our rivers and the habitats that live there by cutting back their water use.
"We believe a Temporary Use Ban is a responsible and vital step to reducing the amount of water being taken from the Rivers Test and Itchen."
Southern Water has reassured customers that there is no direct risk to its customer's water supply.
It is the first time a Temporary Use Ban has been put in place in the region since 2012.
What are the rules for homes?
Households are not allowed to use a hosepipe for any of the following:
Watering a garden using a hosepipe
Cleaning a private motor-vehicle using a hosepipe
Watering plants on domestic or other non-commercial premises using a hosepipe
Cleaning a private leisure boat using a hosepipe
Filling or maintaining a domestic swimming or paddling pool
Drawing water, using a hosepipe, for domestic recreational use
Filling or maintaining a domestic pond using a hosepipe
Filling or maintaining an ornamental fountain
Cleaning walls, or windows, of domestic premises using a hosepipe;
Cleaning paths or patios using a hosepipe
Cleaning other artificial outdoor surfaces using a hosepipe
The company said it had been "left with no choice" but to announce the Temporary Use Ban.
South East Water says anyone who breaks the rules "may be liable on summary conviction to a fine not exceeding £1,000".