Blog: Hidden Challenges of Scotland's Sewers - Deirdre Michie

“Toilets and sinks are not bins. Using them as such has real consequences.”

Deirdre Michie
Chair, Scottish Water

It is not every day that a space hopper finds its way into the headlines.

Last week, news of a bright yellow hopper lodged deep within a Glasgow sewer went viral — featured across newspapers, television and radio, and drawing attention well beyond the communities directly affected.

While the story raised a smile, it also highlights a more serious issue — the vital systems working quietly beneath our communities, and the pressures they face.

Scotland’s wastewater network is extensive, complex and largely hidden from view. Every day, it efficiently carries wastewater away from homes and businesses, treats it to high standards, and returns it safely to the environment. Most people rarely need to think about it — because, more often than not, it simply works.

Blockages

The space hopper may be an unusual cause of a blockage, but the underlying problem is all too common.

Our teams deal with blockages every day, most of which are caused by items that should never enter the sewer network. Wet wipes alone are estimated to be responsible for around 80 per cent of blockages across Scotland.

Each year, we respond to around 36,000 blockages at a cost of more than £7 million. Most of these incidents are avoidable, yet they can result in sewer flooding, environmental damage and disruption for customers.

Once in the system, materials such as wet wipes, fats, oils, grease, cotton wool, contact lenses and sanitary products do not break down. Instead, they accumulate and bind together, forming dense obstructions that restrict flow and place increasing strain on the network.

This is a daily challenge not only across Scotland but worldwide.

Toilets and sinks are not bins. Using them as such has real consequences.

Everyday misuse is increasingly compounded by wider pressures. Climate change is bringing more intense and less predictable rainfall, placing additional strain on combined sewer systems designed for very different conditions. 

At the same time, population growth, development patterns and changing behaviours are increasing demand on the network.

Public interest in how wastewater systems operate is also growing — particularly in relation to storm overflows and wider environmental impacts. This scrutiny is understandable and important.

At Scottish Water, we are increasing transparency about how the wastewater network operates, the challenges it faces, and what is being done to address them.

Monitoring

This includes expanding real-time monitoring and data to provide clearer insight into performance, alongside continued investment in infrastructure and partnership working to reduce the amount of rainwater entering the sewer network.

However, investment alone will not solve the problem. Campaigns such as Nature Calls are helping to raise awareness of what should and should not be flushed. They are making a difference — but the scale of the issue means more action is needed.

The way in which people use the system matters. Small choices about what we flush or pour down sinks quickly add up across households and communities — and we all have a part to play in safeguarding our environment.