Anglian Water’s Director of Water Recycling Emily Timmins, sets out Anglian Water’s plans to cut storm overflows over the next five years. 

Today, we’ve published our annual storm overflow figures for 2024. Storm overflows are pressure relief valves on our sewage network which prevent homes and businesses from flooding during heavy rainfall, by releasing excess storm water  into nearby rivers and water courses.

 
2024 data 

All of our storm overflows have Event Duration Monitors (EDMs) fitted to them which measure the duration as well as the start and stop times of each storm spill. We review this data, and  report it annually to the Environment Agency, as well as publish it on our website. We want to be as transparent as possible about when this activity has happened, so last year our near-real-time map also went live to give a more timely indication of when storm overflows are active, although we still check and verify this data before submitting it as part of our annual return. 

Looking at our data from 2024, it isn’t hard to see that the numbers still aren’t where they need to be – our overall spill duration is up, as is the average spill hours per EDM. 2024 was the eighth wettest winter on record, and the rainiest year we’ve seen in the UK since 1890. It had five named storms – following on from seven in the autumn and winter of 2023. Given all of this, the data isn’t entirely surprising. We can see that 50 per cent of all our spills took place within the first quarter of the year, when our region was in the grip of significant flooding, but it’s still incredibly disappointing for us, and we know our customers may also feel let down. 

Looking ahead – £800m, AI technology, six million baths and 200 pairs of boots 

We also understand the strength of feeling around storm spills, and having apologised as an industry for not responding quickly enough to changing customer expectations on this issue, we have promised transformational action. Because, in the Anglian region especially, we know our climate is going to keep changing, so we have to find better ways of dealing with extreme rainfall. 

Work has been underway to make improvements, and more than £100million of funding released by shareholders has enabled partner projects and fast-tracked operational activity that has been effective in spill reduction, but we need this action right across our region and that was always going to require significant investment not funded in our business plan to 2025.  Next week marks the start of a new investment period, where our 2025 – 2030 business plan will attack the problem from every angle. 

It is our largest ever, with a huge programme of investment worth £11billion targeted at unlocking growth for our region and protecting and enhancing the environment while we do it. Over £1billion of that money is being directly targeted to address sewage spills.    

It will be spent on increasing capacity to hold stormwater at our water recycling sites and across our sewer network by building new infrastructure like storm tanks. Over the next five years we’re building nearly seven times as much storage into our water recycling network compared to the previous five years – a total of 470,000 metres3 – equivalent to nearly six million baths. This work will be fast tracked over the next two years. 

We’ll also be investing £96million to ‘slow the flow’ to prevent top rain and groundwater from getting into our pipes to begin with, making spills less likely. By the end of next year we’ll have almost 50,000 of the latest state-of-the-art AI sewer monitors installed across our network, so we can predict and prevent issues like blockages before they arise. So far these have prevented over 2500 blockages in targeted areas. 

All of this work will be bolstered by an extra 200 pairs of boots on the ground over the next 12 months, all belonging to people dedicated to improving our performance on spills and pollutions. 

This investment will work together to make our network more resilient to wet weather, meaning we can expect a reduction in storm spills over the coming years. It won’t be an easy fix: we have more than 76,000km of sewer pipes and more than 1100 operational sites across our region, so making these changes will take time. But we’re on the right track and  wholeheartedly committed to making sewage spills a thing of the past.