• Spoil excavated from super sewer project used in new 110-hectare habitat 

• 1.5 million tonnes of clay and chalk created basins and varied topography 

• New interpretive signage unveiled by RSPB and Tideway at ceremony at Rainham Marshes 

The RSPB’s nature reserve at Rainham Marshes on the Thames estuary has been furnished with new educational signage explaining the role of the super sewer project in developing a new 110-hectare wetland which is home to a huge variety of birds, insects and other wildlife.  

Tideway, the company behind the super sewer project, repurposed 1.5 million tonnes of clay and chalk to support a new habitat creation scheme next to the existing reserve at Rainham Marshes, the largest scheme of its kind inside the M25.  

The site has undergone a ‘green transformation’ in recent years, with Lapwing, Little Ringed Plover and Red Shank among the species now flourishing. The wetland was created with clay and chalk transported from construction sites up and down the river during the building of the 25km sewer, which is now operational and has so far prevented almost eight million tonnes of sewage from entering the Thames.  

The clay excavated from the super sewer project was used to create an impermeable layer to retain water in new lakes, while the chalk the east of London was being used to create improved topography. 

On Thursday (Sep 4th), teams from the RSPB, Tideway and its contractors gathered for an unveiling ceremony of a new information board which  celebrates the success of the habitat creation initiative. The board is in the reserve Visitor Centre, next to windows that look out westwards onto the new wetland.    

John Sage, Tideway’s Head of Corporate Responsibility, said: “The Tideway project is transforming the health of the River Thames through central London, so to see the excavated spoil reused in this way demonstrates the huge added value of this project. 

“It’s wonderful that visitors to the RSPB at Rainham  will now have a chance to understand the link between the new wetland and this vital new piece of infrastructure in London through this beautifully illustrated information board.”  

The Tideway project has seen about six million tonnes of materials transported by barge, rather than by road, saving 700,000 lorry journeys and almost 25,000 tonnes of CO2. 

Tideway has also funded repairs to the visitor boardwalk around the existing Rainham reserve. The grant for this work came from Tideway’s sustainable financing framework, where interest on debt is reduced if the project hits or exceeds targets for delivering its legacy commitments. Savings triggered by Tideway beating its legacy targets over the last years were used for the RSPB grant.      

Alan Johnson, RSPB Area Manager (Kent & Essex), said: “We’re incredibly grateful to Tideway for their generous support. Their donation will directly help us restore vital boardwalks across Rainham Marshes, making our reserve safer and more accessible for everyone. 

“At the same time, it helps us protect the delicate habitats that these walkways cross. It’s a powerful example of how corporate support can make a meaningful difference for nature and people alike.”