If you’re looking to save money on your water bill and help the environment, you might be asking what is a water butt. A water butt is simply a rainwater collection system, typically a barrel, that connects to a downpipe from your roof. It captures rainwater that would otherwise flow into drains, providing you with a free supply of water for your garden.
This simple device is a powerful tool for any gardener or homeowner. It reduces your reliance on the treated mains water supply, which is better for your plants and your wallet. In this guide, we’ll explain everything you need to know about water butts, from how they work to how you can install one yourself.
What Is A Water Butt
Let’s define the term clearly. A water butt, also known as a rain barrel, is a container designed to collect and store rainwater from your roof via the guttering system. It’s a form of rainwater harvesting on a domestic scale. The basic principle is centuries old, but modern designs make it efficient and convenient.
The typical water butt is made from plastic, though you can find wooden or stone versions. It has a lid to prevent debris and mosquitoes from getting in, an inlet to connect to the downpipe, and a tap near the bottom to access the stored water. Some models include a stand to elevate the butt, making it easier to fill a watering can underneath the tap.
The Core Components Of A Water Butt System
Understanding the parts of a water butt system helps you see how it all fits together. Every system has a few key elements that work in harmony.
The Collection Vessel
This is the barrel or tank itself. Capacities range from 100 litres for a small garden to over 500 litres for larger needs. The material needs to be UV-stable to withstand sunlight and durable to hold the weight of water.
The Lid And Filter
A secure lid is essential for safety and to keep the water clean. Most lids incorporate a filter, often a mesh screen, that catches leaves and twigs from the roof while allowing water to pass through. This prevents blockages and reduces maintenance.
The Diverter Kit
This is the clever piece that connects your water butt to the downpipe. It channels water from the downpipe into the butt. When the butt is full, the diverter allows excess water to bypass the butt and continue down the drain as normal, preventing overflow at the top of the barrel.
The Tap Or Hose Connector
Positioned at the bottom of the butt, this tap lets you draw water. A robust tap is important as it handles the full pressure of the water column. Some systems allow you to connect a hose directly for easier watering.
The Stand
While not always mandatory, a stand is highly recommended. It raises the butt, creating more water pressure at the tap and making it easier to place a watering can underneath. A stand also helps keep the base of the butt clean and stable.
Why You Should Use A Water Butt
The benefits of installing a water butt extend far beyond just having water for your plants. It’s a small change with a significant positive impact.
- Save Money on Water Bills: Using harvested rainwater for your garden reduces your metered water consumption. Over a dry summer, this can lead to substantial savings, especially if you have a large garden or many containers to water.
- Better for Your Plants: Rainwater is naturally soft and free from the chemicals like chlorine found in tap water. Plants, particularly acid-loving ones like rhododendrons and camellias, thrive on rainwater.
- Conserve a Vital Resource: Treating and pumping mains water uses a lot of energy. By using rainwater for non-drinking purposes, you reduce the strain on the public water supply, especially during droughts or peak demand periods.
- Reduce Flooding Risk: In heavy rain, water butts capture runoff from your roof, slowing the flow of water into storm drains and sewers. This can help mitigate localised surface water flooding.
- Always Have a Water Supply: During a hosepipe ban or water restriction, you can usually still use the water from your butt to keep your garden alive, as it’s not from the mains supply.
How To Choose The Right Water Butt
Not all water butts are created equal. Selecting the right one depends on your space, needs, and aesthetic preferences. Here are the key factors to consider before you buy.
Size And Capacity
The size you need depends on your roof area and garden’s thirst. A good rule of thumb is that 1mm of rain on 1 square metre of roof yields 1 litre of water.
- Small (100-200 litres): Ideal for balconies, small patios, or gardens with few plants. It’s a great starter size.
- Medium (200-300 litres): Suits the average garden. This is the most common size and provides a good balance between capacity and footprint.
- Large (300+ litres): Best for large gardens, vegetable plots, or if you have substantial roof area. You can also link multiple butts together for even greater capacity.
Material And Durability
The construction material affects the butt’s longevity, appearance, and cost.
- Plastic (Polyethylene): The most common and affordable option. Look for food-grade, UV-stabilised plastic that won’t become brittle in sunlight. They are lightweight and easy to install.
- Recycled Plastic: An eco-friendly choice made from post-consumer waste. It has the same durability as new plastic but with a lower environmental footprint from production.
- Wood: Often made from oak or pine, wooden butts are attractive and blend into traditional gardens. They require more maintenance, such as re-coating with preservative, to prevent rot.
- Stone or Terracotta: These are the most expensive and heaviest options. They offer a classic, permanent look but are difficult to move once installed.
Shape, Design, And Features
Water butts come in various shapes to fit different spaces.
- Standard Barrel: The classic cylindrical shape. It holds a lot of water but needs space around it.
- Slimline or Wall-Mounted: Designed to fit against a wall or in a narrow space like a side passage. Their capacity is usually smaller.
- Decorative Designs: Some are shaped like terracotta urns, stone planters, or even faux rocks to discreetly blend into the garden.
Key features to look for include a child-safe lid, a fine mesh filter, a robust tap, and an overflow outlet that can be connected to a drain or a second butt.
Step-By-Step Installation Guide
Installing a water butt is a straightforward DIY project that can be completed in an afternoon. Here is a clear, step-by-step guide to get you started.
Tools And Materials You Will Need
- Your chosen water butt (with lid, tap, and filter)
- A sturdy, level stand (often sold separately)
- A downpipe diverter kit (usually included with the butt)
- A hacksaw or junior hacksaw
- A screwdriver (usually Phillips head)
- A spirit level
- A pencil or marker
- A measuring tape
- Optional: Sealant or silicone for a watertight fit
Choosing The Perfect Location
Location is critical for functionality and convenience. Follow these tips.
- Place the butt close to a downpipe that collects water from a large section of roof (like your house, not a small shed).
- Ensure the ground is firm, stable, and level. The stand will help with minor unevenness.
- Position it where you can easily access the tap with a watering can.
- Consider proximity to the plants you water most often to minimize carrying distance.
- Make sure the overflow hose (from the top of the butt or diverter) can be directed safely away from your house’s foundations.
The Installation Process
Now, let’s get the water butt installed and connected.
- Assemble the Stand and Position the Butt: Put the stand together on level ground. Place the empty water butt on the stand. Ensure it is stable and doesn’t rock.
- Mark and Cut the Downpipe: Hold the diverter kit against the downpipe. The kit will have instructions showing where to cut. Typically, you need to create a gap to insert the diverter. Mark the cutting points with a pencil. Use a hacksaw to carefully cut through the downpipe. Support the pipe so it doesn’t crack or bend.
- Fit the Diverter: Slide the diverter unit into the gap you created in the downpipe. Secure it with the screws or clips provided. Follow the manufacturer’s diagram to ensure it is oriented correctly so water flows into the butt first.
- Connect the Hose to the Butt: Attach the flexible hose from the diverter to the inlet connector on the top of your water butt. Push it on firmly. Some kits may require a clamp.
- Prepare the Water Butt: Install the tap according to the instructions, usually by screwing it into a pre-formed hole near the base. Attach the lid and ensure the filter is in place.
- Set Up the Overflow: Connect the overflow hose (from the top of the butt or the diverter) and direct it to a drain, a soakaway, or into a second linked water butt.
- Check for Leaks and Final Adjustments: Wait for rain or run a hose down the gutter to test the system. Check all connections for drips. Make sure the diverter switches flow to the overflow when the butt is full.
Maintaining Your Water Butt
Regular, simple maintenance keeps your water butt working efficiently and your stored water in good condition. Neglect can lead to blockages, algae growth, or even a damaged system.
Essential Seasonal Maintenance Tasks
Break your maintenance down into seasonal chores to make it manageable.
- Spring: Give the butt a thorough clean. Empty it completely, scrub the inside with a mild detergent (not bleach), and rinse well. Clear any debris from the lid filter and gutters above.
- Summer: Use the water regularly to keep it fresh and make room for new rain. Check the filter monthly for leaf build-up. Ensure the overflow is clear.
- Autumn: This is a critical time. Clean the filter frequently as leaves fall. Consider installing a gutter mesh to reduce debris. If you live in a cold area, think about winterizing.
- Winter: In regions with freezing temperatures, empty the butt and disconnect the downpipe hose if possible. Turn the butt upside down or store it indoors to prevent ice from cracking it. Alternatively, leave the tap slightly open to allow ice to expand.
Preventing Common Problems
A little prevention solves most issues before they start.
- Mosquito Larvae: Always keep the lid securely on. You can add a few drops of vegetable oil to the water’s surface to create a film that prevents mosquitoes from laying eggs, or use specific mosquito dunks that are safe for gardens.
- Algae Growth: Algae needs sunlight to grow. Choose an opaque butt or place it in a shady spot. Keeping the lid on also blocks light.
- Bad Odors: Stagnant water can smell. Use the water regularly to keep it oxygenated. Avoid letting organic matter like leaves decompose in the bottom by cleaning it annually.
- Low Water Pressure: The pressure comes from gravity. Elevate your butt on a higher stand to increase the flow from the tap.
Creative Uses For Harvested Rainwater
While watering the garden is the primary use, your harvested rainwater can do much more. It’s perfect for any job where you don’t need potable drinking water.
In The Garden
- Watering lawns, flower beds, vegetable patches, and hanging baskets.
- Filling a pond or topping up a water feature (ensure you have a pump if needed).
- Mixing with liquid fertilizers or weed killers for application.
- Washing garden tools, pots, and planters.
- Providing water for a compost heap to keep it actively breaking down.
Around The Home
With a little caution, you can use rainwater for several outdoor household tasks.
- Washing the car, bicycle, or garden furniture. Rainwater is soft, so it doesn’t leave limescale spots.
- Cleaning windows and exterior paintwork.
- If you have a suitable pump system, it can be connected to supply a toilet for flushing, but this is a more complex installation requiring a plumber.
Remember, unless it is specifically treated and tested, do not use water butt water for drinking, cooking, or bathing pets.
Frequently Asked Questions
Is A Water Butt The Same As A Rain Barrel?
Yes, the terms are generally interchangeable. “Water butt” is more common in the UK, while “rain barrel” is frequently used in North America and other regions. They refer to the same basic device for collecting roof runoff.
How Much Water Can I Actually Collect?
You can collect a surprising amount. Use this formula: Roof Area (sq metres) x Rainfall (mm) = Litres Collected. For example, a 50 square metre roof in a 10mm rain shower will yield around 500 litres of water. Even in moderately rainy climates, a single butt can fill many times over in a year.
Do I Need Planning Permission For A Water Butt?
In most cases, no. Installing a domestic water butt is usually considered a permitted development. However, if you live in a listed building or a conservation area, it’s wise to check with your local planning authority, especially for a very large or prominent installation.
Can I Connect Multiple Water Butts Together?
Absolutely. You can link several butts in series using connection kits. The overflow from the first butt feeds into the inlet of the second, and so on. This is an excellent way to massively increase your storage capacity without taking up more downpipe space.
What Is The Best Way To Clean My Water Butt?
Empty it completely. Use a long-handled brush and a solution of mild washing-up liquid or vinegar to scrub the inside. Rinse thoroughly several times. Never use strong bleach or chemicals, as residues can harm your plants. Clean the filter and lid separately. Doing this once a year, ideally in spring, is sufficient.
Installing a water butt is one of the simplest and most effective steps you can take towards a more sustainable home. It reduces your environmental impact, saves you money, and provides a heathier water source for your garden. With a wide range of styles and sizes available, there’s a water butt to suit almost every home and garden. By following the installation and maintenance tips outlined here, you can enjoy the benefits of free rainwater for years to come. The next time it rains, you’ll be glad you have your own personal reservoir ready to use.