Northumbrian Water is reporting that spills from storm overflows have reduced across the North East due to investment projects and innovative steps taken by the company.  

New data from the Environment Agency shows that the number of storm overflows discharging in the region has reduced by almost 6,000 spills (13%) in 2024.   

The Event Duration Monitoring (EDM) report, published by the EA, also shows that the average number of spills per overflow has dropped from 30 to 26 in the last year, and that the total duration of spills has seen a 12% reduction.   

Northumbrian Water are reporting that the reductions are because of action taken by the water company over the last 12 months that include millions of pounds of investment in infrastructure, with new storm tanks being built in County Durham, underground tanks built in Northumberland and capacity increases being made at treatment works across Teesside and Tyneside.   

The improving EDM results also come despite the impacts of climate change and 2024 being the eighth wettest year on record.   

“EDM results show we have some of the very lowest number and durations of spills in the country"

Richard Warneford, Wastewater Director at Northumbrian Water, said:

“The EDM results show that we have some of the very lowest number and durations of spills in the country.   

“We are pleased to see a reduction in spills, especially during a year filled with numerous named storms and a higher-than-expected amount of rainfall.   

“As well as this, we can also confirm that we did not have any serious pollution incidents throughout the whole of 2024. That is now three years in a row since we last had a serious pollution incident and we are industry leading in this space.  

“This is a great start to seeing improvements across our region - however, we know that there is still a long way to go, reducing storm overflow use is something that our customers care deeply about and it's a real priority for us going forward.”  

£20 million investment in setting up and trialing Smart Sewers project

The water company said it is committed to continuing the hard work and reducing storm overflow spills even further in 2025 and are pioneering an innovative technology known as “Smart Sewers” to help achieve this.   

The Smart Sewers project was launched in July 2024 and involves using AI and sensors to help move wastewater around the companies’ system of pipes in real time to balance flows over a greater area – helping to reduce the risk of needing to use a storm over spill to relieve the network.   

It is a UK-first project, the largest of its kind anywhere in the world and uses a combination of new technology, sensors and AI analytics to lower the risk of overflows needing to happen.  

The water company has invested £20 million in setting up and trialing the project and in February this year connected over 800 sensors and sections of network to Smart Sewers in the Tyneside area, using the technology for the first time in real life and world conditions.    

Smart sewers operated on 15 separate occasions during rainfall in February and every single one showed positive results in terms of stopping storm overflows, that would have normally spilled because of the weather conditions.  

Due to the success of the trials so far, Northumbrian Water has invested a further £5 million to expand the project further across the region, with the next trial locations being in the Marske and Saltburn areas.   

The overall aim is for smart sewer technology to be deployed across all of the areas it can make a difference across the whole of the North East in the future.   

Richard Warneford added:

“The fact that we are seeing such positive results so early on is a great sign, and hopefully means that we can deploy this further across the North East in the near future.   

“Reducing the reliance upon storm overflows is something that is important to everyone who cares about our region, and we are proud to be leading the way with this project.   

“We look forward to seeing how the trials continue over the next few months as we expand down into Teesside.”    

Northumbrian Water is investing £80 million to reduce the use of storm overflows and to upgrade the wastewater network between 2020 and 2025 – with a further £1.7 billion to be invested in a massive environmental program between 2025 to 2030.  

A new team of wastewater operatives have also recently been employed as part of the storm overflow tactical plan.