Why Collect Rainwater in Winter? Rising Water Bills and the Benefits of Rainwater Harvesting

When the British weather turns wet, saving water might not feel like a priority. After all, if it’s raining every other day, why would you need a water butt?

But rainfall patterns are changing, water bills are rising, and making better use of the water available to us is becoming increasingly important.

For homeowners, collecting rainwater can be a practical way to reduce reliance on mains water for suitable uses, prepare for drier periods and make better use of the rainfall that falls on their property.

Whether you’re considering a simple garden water butt or a complete domestic rainwater harvesting system, here’s why now is a good time to think about rainwater.

The UK is experiencing wetter winter

It might seem strange to talk about saving water when the gutters are overflowing, but the latest climate data helps explain why collecting rainwater all year round makes sense.

The Met Office’s State of the UK Climate 2025 report, published in July 2026, found that the UK’s winter-half-year rainfall — October to March — was 13% higher in 2016–2025 than the 1961–1990 average.

The report also found that annual UK rainfall in 2016–2025 was 8% higher than the 1961–1990 average, although it showed no overall change compared with the more recent 1991–2020 baseline.

These comparisons demonstrate why it’s important to consider the period being measured. They do not mean every year is wetter than the last, or that every part of the UK receives more rainfall.

So, what does this mean for homeowners?

It means that rainfall is a resource worth considering throughout the year. Rather than allowing all the water falling on your roof to run away, you could capture some of it and store it for later use.

More rain doesn’t mean we’ll never experience dry spells

If winters are becoming wetter, surely we don’t need to worry about saving water?

Not quite.

The timing and location of rainfall matter just as much as the total amount that falls over a year.

In summer 2026, the Met Office recorded 62 consecutive dry days at Wisley in Surrey. Other locations in southern and eastern England also experienced prolonged periods without measurable rainfall.

This is a reminder that a wet winter doesn’t guarantee a wet summer, and that rainfall can be unevenly distributed across the country.

The Met Office’s climate research also projects a tendency towards drier summers on average in the UK, with stronger drying in southern areas. These are projections rather than a guarantee of what will happen in any individual summer.

For gardens, this creates a straightforward opportunity: collect rainwater when it’s available and store some for suitable uses when the weather becomes drier.

A water butt won’t eliminate the effects of a drought, and its capacity is limited. However, it can provide a useful reserve for watering plants and containers when needed.

Water bills are rising. Could collecting rainwater help?

Water efficiency isn’t just about the environment. For some households, it can also make financial sense.

According to Water UK, the average household water and sewerage bill in England and Wales is forecast to reach approximately £639 a year in 2026/27, up £33, or 5.4%, from the previous year.

Bills vary considerably between water companies and households, and the figures include both water and wastewater charges.

This makes it worth thinking about where household water comes from and how it is used.

For example, if you’re on a water meter and regularly use mains water to water your garden, collecting rainwater could reduce the amount of mains water you need for those tasks.

A water butt is a relatively straightforward way to get started. Instead of using treated mains water every time you water your garden, you can use rainwater collected from your roof.

However, it’s important to be realistic about the savings. A water butt won’t automatically reduce everyone’s bill. Households without a water meter generally won’t see a direct reduction in their bill simply by using less water, and fixed charges remain payable for metered households.

For those looking to reduce mains water consumption more widely, a whole-home rainwater harvesting system may offer greater potential.

The right option depends on the property, household water use, installation costs and the amount of rainwater available.

How much rainwater could your roof collect?

You might be surprised by how much water falls on an ordinary domestic roof.

A useful rule of thumb is that one millimetre of rainfall falling on one square metre of roof represents approximately one litre of water before collection losses.

Let’s take a simple example.

Imagine a house with a roof catchment area of 50 square metres. If 10 millimetres of rain falls, that represents approximately 500 litres of rainfall before losses.

The actual amount collected will depend on your roof, guttering, diverter, storage capacity and how full your water butt already is.

Nevertheless, the calculation shows why rainwater collection can be worthwhile, even when individual showers don’t seem particularly heavy.

A small water butt will only store a portion of that potential rainfall. A larger tank or appropriately designed rainwater harvesting system can provide more storage, depending on the property’s requirements.

You can find out how much your roof can save with our Tank Size Calculator.

Don’t let the winter rain go to waste

The UK may receive plenty of rainfall, but that doesn’t mean water is always available where and when we need it.

With wetter winters, the risk of prolonged summer dry spells and rising household water bills, collecting rainwater is worth considering throughout the year.

Whether you want a simple water butt for your garden or a more comprehensive domestic rainwater harvesting solution, Rainwater Harvesting Ltd can help you explore the options.

Explore our range of water butts or discover our domestic rainwater harvesting systems.