Cunning conveyance

Greener Grangetown
Greener Grangetown was praised for delivering a more resilient sewer network and a street environment that is more attractive and useful

A green infrastructure project in Cardiff was deemed the overall winner in the susdrain SuDS Awards 2020, an event that recognised excellence in sustainable drainage in the UK.


“Greener Grangetown”, which covers 12 Victorian streets and 550 properties in the Welsh capital, is a SuDS project that has been developed by Arup, Cardiff City Council and Natural Resources Wales, and it has been praised for its ability to both improve the resilience of the urban sewer network while providing a street environment that is more attractive.

The judging panel said the project was “… so well considered and so extensive that it was
impossible to say anything negative about it.”

A central element of the project is the use of “rain gardens” – planted areas that mimic the natural environment. These provide a more sustainable method for catching and cleaning rainwater. Plants and trees within the gardens soak up and filter rainwater, capturing and breaking down some pollutants. During heavy storms, water that cannot be absorbed by the soil and vegetation travels through pipes at the base of each garden, where it is discharged into the River Taff. Previously, rainwater run-off had to be pumped 8km for treatment before being discharged into the sea.

Overall the project has provided extra capacity in the combined sewer system, reduced CSO spills into the River Taff, and reduced operational costs for the local authority. For residents and commuters, the project has also improved the quality of the public realm, delivering improved cycling and pedestrian infrastructure across a city centre neighbourhood.

The judges praised the elegance of the solution. “Clever systems are used to convey water for which the energy savings have been calculated and the residents love it”.

One of the winners, Chris Ellis of Arup, said: “so many amazing people have helped make this project a success.” He added: “I hope projects like Greener Grangetown become the norm, rather than the exception.”

Martyn Evans, Natural Resources Wales, said he had been involved in the project since 2012 and “the aim from the very beginning was to design an innovative, sustainable and future-proof drainage system that could create a healthy and resilient local environment for generations to come.”

Also Highly Commended in the same category of award (Large scale retrofit) was Sheffield City Council for its Charter Square sustainable redevelopment, a project that focuses on keeping water on or near the surface in rain gardens and green streets, while avoiding pushing it underground through conventional gulley or piped systems. And Haringey Borough Council was also highly commended for its Crescent Gardens SuDS project, which employs rain gardens, swales, detention basins and planted trees – delivering improvements in water quality and water management.

The “New build large scale SuDS” category was jointly won by two groups. Raeburn Farquar Bowen picked up the award for its project in Bertha Park, Perth. It uses permeable paved driveways, filter strips and swales, ponds and infiltration – the centrepiece of the development is a new park with large SuDS ponds. The other winner was Civic Engineers, for its Climate Innovation District, in Leeds. The latter is a £250m car-free housing development in Leeds on a brownfield site. Said to be “one of the most comprehensive SuDS systems in the UK” it uses a number of different methods to deal with surface water run-off, including green roofs, rain gardens, permeable pavements and detention basins.

There was also a “SuDS Champion” award, recognising an industry figure for their role in inspiring, influencing and informing others. This was picked up by George Warren of the Greater London Authority. Speaking of the post-pandemic world, he said “now more than ever” we need to make a stand “to ensure that SuDS are the norm not the exception.”
CIRIA’s susdrain SuDS awards were announced online on Thursday 16 July 2020.