How to help manage rainwater runoff

We can all help to protect the environment by improving how we manage rainwater runoff.

Heavy rainfall results in increased runoff from roofs and surfaces leading to more water entering the sewer network, which can cause storm overflows to automatically operate. If this rainwater is captured before it enters sewers, it could reduce how often they operate.

You could use the rainwater you collect on your garden which saves water, and money if you’re on a meter. And if you can prove that the majority of the rainwater from your property doesn't drain to a public sewer, you can apply for a reduction on your sewerage bill.

We recognise it is largely our responsibility to reduce storm overflows, which is why we are spending £3m a month to tackle the issue. Learn more about how we're reducing storm overflows.

However, there are also some things you could do to reduce the amount of surface water that enters the sewer network.

Use a water butt

Water butts are used to collect and store rainwater that lands on the roof of your home, garage, shed or greenhouse. This water can then be used to maintain your garden during dry weather.

Some water butts are designed to remain partly empty by allowing some of the water to slowly drain after a storm. It can then accept more rainwater when another storm begins. This design is best for reducing the amount of rainwater that goes down the drain.

If you install a water butt, we recommend directing its overflow to your garden. If you have a rain garden or soakaway, you should direct it there instead.

Create a rain garden

A rain garden is a shallow area of ground, or a raised bed, that consists of absorbent soil with plants that can handle temporary flooding.

Creating a rain garden involves directing your property’s downpipes towards this section of your garden instead of a drain.

These types of gardens are low maintenance and require no watering once plants have become established – they can also absorb up to 30% more water than a lawn.

Think about drainage

If you're considering paving over your front garden, upgrading your driveway or constructing a patio, it’s important to think about drainage beforehand.

Concrete and block paving are not great options when it comes to drainage. Loose stones or gravel are much better as they allow water to drain through them.

If possible, we recommend leaving as much green space around your property as possible – lawns are great for soaking up rainfall.

Close up view of grass

Build a soakaway

A soakaway is essentially a hole in the ground filled with stones or specially designed plastic crates. They help prevent flooding and reduce stress on the sewer network.

Soakaways are built underground and are connected to a downpipe, which carries rainfall away from the property.

They allow water to soak directly into the ground which prevents it from going down the drain.

Apply for a rainwater drainage allowance

Complete our online form to apply for a rainwater drainage allowance.