Hundreds of sewage overflows in Ashfield last year

Storm overflows normally happen when the sewage system is at risk of being overwhelmed, such as after a heavy rain, or during higher levels of groundwater.

In these cases, water companies may need to release excess water and sewage into rivers and the sea, to prevent water backing up into the streets and people's homes.

This has an impact on the quality of our natural water sources, with some charities alleging storm overflows are being misused and under-reported.

Figures from the Environment Agency show storm overflows were used 818 times within Ashfield district in 2022, discharging for a total of about 4,222 hours.

All of these spills were from Severn Trent Water’s network, although Mansfield may also be impacted by overspills from areas it shares water sources with.

The Rivers Trust said it was particularly concerned by storm overflows being used during hot periods.

Tessa Wardley, charity director of communications and advocacy, said: "Discharging untreated sewage in dry weather is bad for both human health and river health – lower river flows mean more concentrated pollutants at a time when more people want to enjoy their rivers."

"Although a problem in their own right, these discharges also point to greater problems in our sewerage and river systems. This could be blockages in the system, groundwater seeping into broken pipes, misconnections, or just poor management choices.

She urged “robust, urgent action”.

Severn Trent Water saw 44,765 overspills across its network in 2022, with 99 per cent of the company's facilities reporting overspill data last year.

In total there were more than 300,000 overspills across England in 2022 – a 19 per cent reduction on more than 370,000 in 2021, although this may have been the product of weather conditions rather than improved infrastructure.

Water minister Rebecca Pow said the amount of sewage pumped into rivers is “utterly unacceptable”, adding the Government has a plan to tackle pollution.

She said: “Targets set by the Government to reduce storm overflows are very strict and are leading to the largest infrastructure programme in water company history – £56 billion over the next 25 years. Shortly, water companies will also publish action plans for every storm overflow in England.”