Reducing storm overflows to improve local water quality
Wastewater improvement work is taking place in Falmouth to help reduce the use of storm overflows and protect water quality in the local area, including nearby beaches and rivers.
Investigations identified that parts of the sewer system can struggle during periods of heavy rainfall. This is influenced by factors such as surface water and groundwater entering the system, along with increasing demand. A phased programme of improvements is being delivered to address these challenges and strengthen the long‑term resilience of the wastewater network.
This scheme forms part of the wider £760 million Turning the Tide programme, which is delivering wastewater improvements across the region.
Project phase 1: Queen Mary Gardens
The first phase of the scheme is focused on improvements at Queen Mary Gardens. This phase is designed to reduce pressure on the sewer system during heavy rainfall by increasing the amount of wastewater that can be temporarily stored and treated.
A new stormwater storage tank is being constructed at Queen Mary Gardens, with a capacity of 302,000 litres. The additional storage will allow more wastewater to be held during periods of heavy rain and treated when capacity becomes available, reducing the need to use storm overflows.
The works taking place in Gyllyngvase car park. To enable safe access for construction, Gyllyngvase car park will be closed from October 2025. The car park is due to be reinstated the week commencing 11 May 2026.
Project phase 2: Further improvements across Falmouth
The second phase of the Falmouth Sewer Improvement Scheme will build on the work at Queen Mary Gardens and deliver further improvements across the wider catchment.
From June, the next stage of design work is expected to begin. This will identify further improvements, which may include reducing groundwater entering the network, separating surface water from the sewer system, and providing additional storage where needed. More detail about these plans will be shared once the design work is complete.
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 brand new storm storage near Queen Mary Gardens and investigating other potential areas.