Providing you with better water quality
We’re investing to reduce the use of storm overflows in Lyme Regis, helping to improve water quality in local rivers and the sea. This major investment in Lyme Regis is part of our £760 million Turning the Tide programme, to improve water quality across the region.
Why do we have storm overflows?
Storm overflows act like safety valves when the wastewater system becomes overwhelmed, typically following heavy rainfall. Excess wastewater is released from storm overflows to prevent the system from backing up and overflowing in people’s homes and workplaces.
We want to use storm overflows less by finding solutions so more wastewater can be stored and treated without being released into the environment.
Find out more about storm overflows
To ensure our solutions are effective, we survey a local area to understand factors that cause overflows to be used. We’ve surveyed Lyme Regis to help inform several projects aimed at reducing storm overflow use in the area.
Separating combined sewers
Keeping surface water from rainfall out of the main sewers will make it less likely we need to use storm overflows. We will be constructing a new surface water drainage network, so this water is separated from the flows that need full sewage treatment.
To do this, we’ll dig trenches, lay new pipes under roads, and reconnect existing Gullies to the new network as required. This will help improve local water quality in rivers and the sea by reducing storm overflow use. It will also help to reduce flooding risk.
These works will be taking place throughout Lyme Regis in late 2026.
New storm storage locations
At Horn Bridge the storm tank will provide 100,000 litres of storage.
At Jericho the storm tank will provide 90,000 litres of storage.
And at the sewage treatment works an additional 480,000 litres of storm water storage will be installed.
These tanks will be installed by 31 March 2027.
New storage tanks in Lyme Regis
Climate change is bringing periods of heavier rainfall. There are storm tanks to hold this water until it can be treated, but the intensity of the rain means they sometimes run out of capacity. To help this we’re looking into building new storm tanks in Lyme Regis, which would store additional wastewater at times of heavy flow.
Combined sewers
Combined sewers carry both foul sewage from homes and businesses and rainwater from roofs, paved areas and in some areas, run off from roads to the treatment works. Rainwater itself doesn’t need treatment before being released back into rivers, but where it enters a combined sewer network it uses valuable capacity and adds pressure to our pumps and storm tanks.
The best way to reduce this pressure is to separate foul and surface water flows. By building one sewer for foul sewage and another for rainwater, we can keep clean water out of the treatment process and release it safely back into rivers after passing through an oil interceptor. Customers can also play a big part by keeping rainwater out of combined sewers, for example through soakaways or other drainage solutions. Checking how your roof and driveway runoff is connected can make a difference. If none of your surface water drains to the public sewer, you may qualify for a lower bill and help ease pressure on the system during wet weather.