We work hard across our region to keep our sewers working as normally as possible when faced with high groundwater levels.
Our priority is to ensure our customers can continue to use their toilets and sinks, so we use tankers and mobile pumps to drain excess water from our sewer network.
We have also been investing to seal our sewers and minimise the amount of groundwater and surface water forcing its way into our pipework.
We respond to such emergencies by ‘tankering’ – pumping wastewater from a sewer into a tanker lorry and taking it away for treatment.
This helps to keep the sewers flowing, so they can deal with the wastewater from homes and businesses – the job they are designed to do – and helps protect customers' properties from being flooded internally.
Where more help is needed, we carry out over-pumping. This involves pumping heavily-diluted wastewater from sewers through a screening system before releasing it into nearby rivers, streams or ditches.
Over-pumping is necessary to protect properties and can move large volumes of water quickly – roughly 50 to 60 litres a second compared with a couple of litres a second for a tanker.
Biological treatment tanks will improve the quality of the floodwater pumped from our sewers.
Working with Atac Solutions Limited, we developed new transportable biological treatment tanks.
These use bacteria to treat the water from our pumps on site before it is recycled to local watercourses.
Each tank can improve the quality of the water we treat by as much as 40%. They also allow more oxygen to be applied during the treatment process which helps maintain the natural balance of rivers for local wildlife.
We used 10 treatment tanks across Kent and Hampshire on a trial basis during 2013–14 and, if required, will deploy them again.