What we're doing
South West Water has now installed a 100,000-litre tank at The Ham in Sidmouth. This tank will capture excess flows during heavy rainfall, storing them until they can be fully treated. This will help reduce storm overflow spills from The Ham Pumping Station and protect water quality at Sidmouth Town Beach, which has consistently received an “Excellent” bathing water rating.
Further work is taking place to complete mechanical and electrical installation, commission the system and restore the site. The Ham will remain closed for recreational use while works are completed, and the area is expected to be reopened around June 2026.
Programme of works
| Date | Activity |
|---|---|
| October to December 2025 | Site setup and drilling trial holes to check existing services. |
| January to April 2026 | Building the new storm storage tank. This includes groundworks and structural works. |
| April 2026 to June 2026 | Finalising the tank structure and restoring the work area. |
| March to June 2026 | Electrical and mechanical installation and system commissioning. |
| June 2026 |
Removing the site compound and restoring the area. |
Works already completed
Phase 1: February to September 2024
We lined 251 metres of sewer, repaired the sewer in 14 locations, and repaired 7 manholes.
Phase 2: September to November 2024
We inspected long sections of sewer thought to be abandoned and filled them with grout to stop groundwater getting in.
Phase 3: November 2024 to April 2025
We lined 354 metres of sewer, repaired the sewer in 29 locations, and repaired 25 manholes.
Total repairs during this time:
• 8,475 metres of sewer inspected with CCTV
• 605 metres of sewer lined
• 43 locations repaired
• 32 manholes inspected and repaired
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 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.
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.