When rain storms come, drains and Southern Water's sewers and wastewater treatment system sometimes struggle to cope.
In the worst cases flooding from sewers may occur, but in less severe instances a mixture of wastewater and surface water (rainwater that's entered the sewer) can overflow from the storage wells at our waste pumping stations. These storm overflows are permitted by the Environment Agency under these circumstances and are required to prevent flooding.
Although they're permitted, we're looking at ways of minimising these overflows, as protecting the environment is our top priority.
With warning, we try and reduce the chances of overflows by pumping out the wells to give as much headroom as possible.
But this is labour intensive - it relies on teams being called up and notified of weather warnings.
So we're now taking part in trials of an amazing new system called StormHarvester which can reduce the chance of overflows by as much as 80%.
Before the rain comes
Using artificial intelligence, StormHarvester's short to medium term rainfall prediction system allows waste networks to take advantage of every litre of capacity in the system. Action is taken well before it starts raining, enabling the network to adequately prepare for extra run-off and so prevent flooding.
The StormHarvester control centre receives location-specific rainfall predictions from the Met Office or satellite images. The controller receives these alerts and predictions of rainfall amounts, and also knows the safe operating levels of tanks, wells and chambers. It then automatically starts pumps, and opens and closes valves.
Of course the system provides a safe operating regime, which is further enhanced with automated text messages that are sent to operators to let them know what's happening.
Brian Moloney, Managing Director of StormHarvester, says we were an easy choice as partner for the trials. "It's a natural fit - the geographic location helps but Southern Water is a leading and innovative company and an ideal partner," he says.
We're really excited to be part of this trial and suitable sites are being selected ahead of the rainier weather in the autumn.
Paul Kent, Wastewater Strategy Manager