We're working fast to reduce spills in Sidmouth
Sidmouth has enjoyed Excellent bathing water for many years now.
But we know that sometimes the sewer system is struggling to cope. Our investigations tell us that this is for a number of reasons including population growth in the area, groundwater entering the sewers, and the age of some of our assets.
We're on a mission to reduce the impact the town's sewerage system is having on the environment.
What we're doing
This scheme has four major elements to deliver before our government-imposed deadline of 30 March 2028.
1. Infiltration
Infiltration is when surface water or groundwater enters our sewers in places it's not meant to (e.g. through manhole covers).
This means that a lot more wastewater enters the sewers and increases the risk of activating our storm overflows.
To stop infiltration we'll be lining, repairing and replacing our pipes and manhole covers in hotspot areas. We call this rehabilitation work.
2. Storm storage
Storm water is the number one cause of storm overflows. The huge rainfalls we're experiencing as climate change takes hold are overwhelming our sewers, meaning our storm tanks fill up faster and start overflowing before our pumps have chance to reduce the volume inside them.
We're hoping that our work to reduce infiltration will help reduce the amount of storm water entering our sewers.
But, we're also making sure there's enough storage to hold it all. That's why we're looking into building a brand new storm tank near The Ham.
3. Combined sewers
Combined sewers take both foul sewage from homes and businesses, as well as surface water from roads, to the treatment works.
Being rainwater, surface water doesn't need much treatment before being released back into rivers. Sending it to the treatment works not only wastes energy and money in transporting and treating it, but also risks overloading our pump stations and storm tanks.
By seperating sewers (building one to hold the foul flows and one to hold surface water) we can reduce the flows inside our sewers and reduce the risk of storm overflows. The surface water is released into rivers after going through an oil interceptor.
4. Our storm overflows
Following extensive investigations, the work we're doing in this scheme is expected to significantly reduce our reliance on the storm overflows in Sidmouth.
But, they will still play an important role in internal flood-prevention. That's why we're investing in their maintenance - upgrading their screens and relocating our monitoring chambers.
This work will help reduce the impact of overflows on the environment, and allow us to better monitor, check and maintain the overflows.
When we're doing it
We've done a lot of investigating and surveying to find the best solution for Sidmouth's sewerage system. Some of those are still ongoing, and we've got others planned as the scheme moves forward.
We're still in the designing and developing stage, so we don't have any confirmed dates of when the work is due to start.
However, a estimated delivery programme is below. These dates are subject to change.
| Projects | Estimated dates |
|---|---|
| Infiltration reduction |
Works has been split into 3 phases for Infiltration Reduction within Sidmouth:
|
| Increasing storm storage |
Design of the tank and associated works is in progress and due by August 2024. Current proposed construction timeframes: October 2024 to March 2025 |
| Separating sewers | Surveys and investigations are underway to inform design options for surface water separation within the Sidmouth catchment. Initial investigations have been completed to inform options ahead of designing the final solution. |
| Designing modifications to storm overflows | Confirmation of condition and scope of modifications are in progress, with modifications due to be complete by March 2025. |
Update April 2024: Following our borehole investigations around The Ham, we needed to do some reinstatement work to return the areas back to how we found them. Unfortunately, the wet weather made this impossible to do straight away. We went back and completed this work later in the month when the weather was drier.