From Sewage Spills to Rain Gardens: What you can do at home to help our Rivers

Helen Tandy, Founding Director, Eco Communities 

At our last nights People Planet Pint (wrote it the next day but not been well and so late posting) gathering in Chester, we had one of those conversations that starts with a simple question —

“why does sewage end up in the River Dee when it rains?” — and goes somewhere really worthwhile.

We were joined by Rob Hirst from The River Dee Trust, and the discussion covered everything from the mechanics of combined sewer overflows to what communities and homeowners can actually do closer to home. As Surfers Against Sewage‘s Chester representative, this sits right at the heart of what I care about, and I left the evening feeling genuinely energised.

Then this morning, a post on LinkedIn stopped me in my tracks. A rain garden installed in a driveway, a narrow planted strip running underneath the car had gone viral on Instagram, with hundreds of comments from people who’d never heard of such a thing but immediately wanted one. It felt like exactly the right moment to write this.

So why does sewage end up in our rivers?

Many older UK towns and cities, including parts of Chester have what’s called a combined sewer system, where rainwater runoff and foul sewage (from toilets, sinks and so on) share the same pipes. In dry weather, this works fine: everything flows to the treatment works. But in heavy rainfall, the volume of water surging into the system can overwhelm capacity. Rather than backing up into homes and streets, it’s released — untreated — into rivers and waterways through Combined Sewer Overflows (CSOs).

This is legal. It’s also deeply problematic. The River Dee — our river — is affected by this. It’s one of the reasons why campaigning for bathing water status on the Dee matters so much, because it would trigger greater scrutiny and accountability around these discharges.

Water companies absolutely need to invest more in infrastructure. But while we push for that, there’s something practical we can do at home.

What are Household SuDS?

Sustainable Drainage Systems — SuDS, manage rainwater naturally, where it falls. Instead of funnelling runoff straight into the sewer, they allow water to soak into the ground, evaporate slowly, or be captured and reused. Less water in the sewer means less risk of overflow, and less sewage reaching our rivers.

Here are the most accessible options for homeowners:

Rain Gardens
Shallow, planted depressions that capture runoff from roofs or driveways and allow it to pool temporarily before being absorbed by plants. They can be surprisingly small and beautiful, and yes, you can install one as a strip in your driveway, exactly as that viral post showed. Moisture-loving plants do the work; you get a wildlife habitat as a bonus.

Raised Planter Rain Gardens
Not everyone can dig a depression into their garden — and that’s where the raised planter version comes in. Instead of excavating downwards, you build up a contained bed using timber, sleepers, stone, or reclaimed materials, filled with a free-draining soil mix. See beow for more info and how to build one – see also this business for more info – click here

Permeable Paving
Replacing a solid concrete or tarmac driveway with permeable block paving, gravel, or porous surfaces allows water to filter through into the ground rather than rushing into the drain. Under current UK planning rules, any new or replacement front driveway over five square metres must use a permeable surface or direct water to a permeable area — so if you’re planning a driveway refresh, this is already the legal expectation.

Water Butts
Simple, affordable, and underused. A water butt connected to your downpipe captures roof runoff for garden use, taking pressure off the drainage network during storms. If you have the space, multiple butts or a larger tank make a real difference.

Soakaways
An underground gravel-filled pit or purpose-built structure collects rainwater and lets it seep slowly into surrounding soil. Often used alongside other drainage measures, particularly for roof runoff.

Are there financial benefits?

Possibly, yes. In the UK, if your surface water doesn’t drain into the public sewer network, you may be eligible for a reduction on your water bill, sometimes called a surface water drainage rebate. It’s worth checking with your water company  to find out whether you qualify, particularly if you’ve already made changes to your drainage.

Where can I find out more?

For guidance on what’s permitted and what standards apply, the best starting points are:

• The Flood Hub — regional flooding and drainage advice for the North West: thefloodhub.co.uk
• Cheshire West and Chester Council — local planning and drainage guidance
• The River Dee Trust — working with communities across the Dee catchment on nature-based water solutions: deetrust.org
• Surfers Against Sewage — campaigning for clean rivers and seas, with local reps in Chester: sas.org.uk

The bigger picture

Individual action isn’t a substitute for systemic change, water companies must be held to account, and investment in our ageing sewer infrastructure is long overdue. But household SuDS are one of those rare things: genuinely helpful and within reach. A rain garden in a driveway won’t save the Dee on its own. But hundreds of them across Chester and Cheshire West? That starts to add up.

If you’re curious about what might work for your property, feel free to get in touch. And if you missed last night’s People Planet Pint, we’ll be back in July with a new topic.

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