Turning Sheffield from Grey to Green

Sheffield plans to be a carbon neutral city by 2030, aided by one of the largest SuDS retrofit projects in the UK

Sheffield has long laid claim to the title of the UK’s greenest city, due to the sheer amount of woodlands, parks and green spaces within the city limits.

This legacy is largely the result of a city plan (the Abercrombie Plan, 1924) from the early 20th century that established a network of linked parks and protected spaces running from the city’s rural hinterland through the suburbs to the edge of the city centre: what in today’s terms would be called visionary large-scale urban green infrastructure planning.

Now, nearly one hundred years later, the city is seeking to redefine contemporary concepts of green infrastructure by extending this vision into the very heart of the city and applying it on a truly transformational scale, in the context of climate change adaptation. Crucially, the Sheffield approach seeks to switch the dominant green infrastructure focus from achieving ecological function to one where aesthetic considerations, beauty and public acceptance are given at least equal weighting.

Sheffield Grey to Green project

© Nigel Dunnett

Furthermore, it is doing this through the use of innovative, sustainable and researchbased horticulture, within a strong landscape design framework. It’s an attempt to give new meaning to the Garden City, or City in a Garden idea: creating a ‘Sheffield City Garden’ that seeks to infiltrate multifunctional and beautiful greening at every opportunity to future proof the urban and human environment against climate and weather extremes.

The current strategy has its roots in the 1990s, when a landscape-led approach was taken to regenerating Sheffield City Centre. The ‘Gold Route’ from Sheffield Station concourse through to the city centre and on to the University of Sheffield has won much acclaim for its high-quality definition as a civic route, with its high profile horticulture and craftsmanship. The much-loved Peace Gardens sit at the core of this route and set a benchmark for a civic garden with year-round interest, as a setting for a wide range of activities and for a high standard of maintenance.

However, what were then seen purely as attractive and enjoyable spaces, or used as high quality settings for regeneration, now need to be something much more whilst still achieving these important goals. As a result, Sheffield’s new approach to city centre public realm aims to contribute to a healthier city by concentrating on the climate change resilient benefits from its urban spaces and this in turn places renewed attention on the exciting potential of the public realm.

Sheffield Grey to Green project

© Nigel Dunnett

A major impetus for this was the catastrophic flooding that parts of the city centre suffered in June 2007, following three days of continuous heavy rain, causing the water level in the River Don to rise by at least five metres and subsequently burst its banks into the city. Millions of pounds worth of damage resulted and two fatalities. Subsequent investigations identified the amount of built development and hard surface within the urban catchment of the Don as being a major cause of this flooding following extreme weather.

As a result, a raft of new measures were implemented to prevent this happening again, including a renewed focus on urban SuDS and water-sensitive design. The most visible expression of this is the city’s Grey to Green scheme. This is the UK’s largest retrofit SuDS project and also one of the UK’s largest inner city ‘Green Streets’. Design work started in 2014, with Phase 1 of the 1.6-kilometre scheme installed in 2016 and Phase 2 is currently under construction.

The scheme took advantage of a transport restructure that enabled the narrowing of part of the former dual carriageway inner city ring road from four lanes to two. The associated liberated space was given over to extensive areas of rain gardens and bioswales, and widened pavement spaces for pedestrians. Phase 2 fully integrates a cycle network in addition.

This is a truly multifunctional project, aiming to increase urban biodiversity and create a green corridor, protect pedestrians from air pollution though multi-layered planting, achieve urban cooling through increased tree planting, treat contaminated water, contain potential micro plastics and promote health and wellbeing.

But, in addition, a key aspect was that this inspirational landscape scheme would also provide a stimulus and catalyst for further inward investment in the area – a real economic benefit too. Research conducted by the University of Sheffield has indicated great public support for this naturalistic urban scheme in Phase 1 and a significant change in daily walking patterns by a proportion of users.

The planting scheme in Grey to Green has been created through a collaboration with Sheffield City Council and Professor Nigel Dunnett of the Department of Landscape Architecture, University of Sheffield, and is a manifestation of a long-term relationship between the city and the University. Nigel and colleagues have defined contemporary approaches to sustainable planting design on a wider basis and this is apparent in the city through the development of ‘Pictorial Meadows’ and through the use of specialist landscape contractors ‘Green Estate Ltd’.

Sheffield Grey to Green project

© Nigel Dunnett

Indeed, this is a great example of how innovation in horticulture can lead to new enterprises, which in themselves allow new approaches to be implemented and maintained. It’s a genuinely holistic approach, involving wider partnerships with the Universities and businesses and it cuts across and brings together different sections within the council. We are now setting out a statement for the Sheffield’s future as the city starts to understand what is required of it to achieve its target of being carbon neutral by 2030.

The challenge is to investigate how we can expand these ideas. The recent decline in the country’s retail offer on the high street presents a new and real opportunity to re-imagine this traditionally retail-dominated space as a new city centre garden for retail, leisure, enjoyment, climate resilience and healthy living. How to create and retrofit transformational green infrastructure in city centres is one of our greatest challenges, but by creating beautiful, sustainable, ecologically-functioning green public realm, we believe we have hit on a formula that mainstreams innovative green infrastructure in a way that is practical, cost-effective and popular.

Nigel Dunnett is Professor of Planting Design and Urban Horticulture, Department of Landscape, University of Sheffield Zac Tudor is Principal Landscape Architect, Urban and Environmental Design, Sheffield City Council