Water Butts




Download a 'How to Install a Water Butt' leaflet

Used correctly and with waterwise gardening, a water butt will provide all the water you need to keep your garden alive throughout the long hot summer months.

Even without a hosepipe ban it doesn’t make sense to be using high quality treated drinking water on your garden. Waterwise encourages everybody to practice waterwise gardening. This means using rainwater from a water butt on your plants, delivering it with a watering can or drip irrigation system and mulching your soil. This way you can have a beautiful, living garden which uses a very small amount of water.

You’ll also reduce your carbon footprint as each household has half a tonne of water delivered to their door every day. The energy costs associated with treating and pumping this water are huge.

If every household in the UK got a standard water butt this would save about 30,000 million litres of water each summer – that’s enough to fill Bewl Water reservoir! (This was the one that was running on empty all last summer 2006).

Outdoor water use accounts for around 7% of the total water use, but in the summer this can rise to over 50% of peak demand. However, this is one of the easiest areas to save water as we don’t need to waste valuable tapwater on our plants. Plus, plants actually prefer rainwater – it is better for them!




  • There is growing interest in the domestic use of rainwater. Rainwater is very different to greywater.
  • Rainwater - involves collecting the water from roofs. The most common method of storage is to use a water butt.
  • Greywater - This is dirty water. Greywater involves re-using water from any area of your home apart from the toilet. Greywater should never be stored.
  • Blackwater – This is water from your toilet and should never be put on your garden.

Storing rainwater

Rainwater can generally be stored for long-periods without problems.

Never put greywater into a water butt

There are products that can be added to water butts to ensure no odour and bacterial build-up. Some people encounter mosquito problems with water butts, this can be solved by fitting a lid or placing a layer polystyrene balls (you can use waste packaging) on top of the water. Alternatively a layer of vegetable oil does the same job.

Never put greywater into a water butt. This can pose a human health risk, greywater should never be stored.


To decide what size water butt you need you should consider how much water you're likely to need depending on your plant varieties and the size of your garden. Any number of water butts can be connected together. Have a look at the different designs available below.


There are now some much larger water storage tanks widely available. These can range from a few hundred to a few thousand litres.

There are four types of domestic storage tank.

  • Standard water butt - A standard water butt is between 100 to 300 litres in size. It is normally barrel shaped or square with a tap near the base.
  • Ornamental tanks - these are above ground and can generally store between 50 and 300 litres and can be in the shape of boulders, fences, benches etc.
  • Large above ground tanks - these are large rectangular tanks and are normally placed next to a garage, they will require a level, firm base (slabs or tarmac) These can hold up to 2000 litres of water.
  • Large underground tanks - these tanks can store several thousand litres of water and require a pump. Because of their size they can be connected your toilet and your washing machine too. If you are doing this, contact your regulator to ensure you comply with the water fittings regulations. Be careful, you may require building consent if you are placing the tank close to your house.