How has climate change affected the way that water management has evolved for playing surfaces and the surrounding stadium?

Tom – Legislation designed to prevent flooding in urban areas now requires the majority of new developments to store stormwater onsite for a set period of time. The amount varies from country to country, but the nature of sports stadiums (large roof area, precincts, minimal green space), means that as designers, we can be innovative when developing site water storage. In addition, climate change is generally resulting in long periods of dry weather, increasing reliance on irrigation systems. When designing water harvesting solutions into a building schematic, STRI look to efficiently work with nature, capturing water when there is too much and releasing it when there is not enough. 

Christian – The impact of climate change has given particular focus to turf managers and researchers on water sourcing methods, its' quality, security of supply and how to maximise the use of the available water. Stadia being a highly designed and technologically enabled environment allows for a more intensive and managed response than other venues.

Climate change has driven innovation and the identification of research requirements to fill gaps of knowledge and available solutions. A significant area of research we are now focusing on is how alternatives (non-borehole or mains water) can be used, without increasing the challenges in terms of quality and agronomic implications. STRI has found that developing methods to recover and treat black and grey water, condensate water recovery, as well as more common rainwater harvesting from the stadia roof and around the stadium precinct, provide turf managers with multiple options to integrate recycling and water reuse for ongoing pitch and turf management.

Lee – The playing surface represents a massive opportunity; with space inside and outside stadia developments at a premium. STRI was recently involved in a project for a London based Premier League club to design a bespoke holistic water management solution for a new £1 billion stadium. Being situated in an urban environment, the site was enormously constrained legislatively and practically. The new roof structure increased surface area significantly and as a result, there was no possibility of stormwater storage as deep excavations for traditional tanks weren't viable.

Our solution was relatively simple. Having 8,000m of turf opens up the possibility to use that area to create geocellular storage under the pitch. That void can then be utilised to capture, attenuate and reuse water from a myriad of sources, namely, stormwater collected from the roof. Thanks to innovative engineering, the scheme transferred water under the pitch zone into the geocellular structure, enabling reuse for irrigation or discharge after the storm peak at a lower rate.

How is technology mitigating the effects of climate change within stadia?

Tom - Irrigation systems are becoming increasingly more efficient, relying on detailed data sets to make decisions. Water can be applied according to detailed soil moisture readings, as well as accurate weather forecasts to ensure that water is not wasted or applied in advance of heavy rainfall. The Polysync system, co-developed by STRI is one of the smart water systems that now exist. It uses weather forecasts to release water from stormwater storage tanks in advance of storms, increasing attenuation capacity during storms, and ensuring more water can be reused in irrigation systems after storm events. 

STRI has also taken systems and design techniques from urban water design and incorporated these into sports pitch designs. Polypipe’s Permavoid system acts as an alternative drainage layer to gravel, storing water and passively irrigating the pitch from below.

Christian - Stadia are technologically advanced constructions where all aspects of the growing environment can be managed and adjusted dynamically in response to local climate experienced at any given moment. The ability to heat and cool pitches, provide light and airflow, and precision water and nutrient application all help to provide control of the growing environment and give an element of resilience to some of the effects of climate change. 

Prior to introduction to the market, Permavoid underwent a meticulous 4-year field trial at STRI’s research sites in both the UK and Australia, the results of which showed that rootzone drained just as effectively as convectional top-down irrigation. Additionally, the Permavoid system allows for significantly shallower rootzones (by 20-30%) with no negative effect on the turf, and water savings of up to 60% while the rootzone was still maintained at optimum moisture content.

Rod – Water management of sports stadia requires a power source, electricity supplied via a third party. Introducing solar glazing and lightweight solar panels into the roof and façade structures can generate on-site electricity that can reduce supply from third parties and even generate hot water for the stadia. 

What considerations need to be given to different sustainable water management systems across different climates?

Lee – Each climate represents different problems to resolve. Extreme weather events such as floods, heatwaves, droughts and storms are increasing in number and severity, meaning water management infrastructure is increasingly vital.

STRI use technology to help manage water in innovative ways. Areas susceptible to drought for example, benefit from passive irrigation being integrated into pitch and landscaped areas, reducing losses from evapotranspiration by up to 60%.

The most effective sustainable water management solution is fully integrated and considers location; where the capture and reuse of water from precinct-wide drainage, black and grey water, condensate and irrigation can all be treated, attenuated and then reused for pitch and landscape irrigation or used as a non-potable water supply within the stadium.

Christian – A significant development in innovation resolves how irrigation water can be used more efficiently to mitigate extreme weather events. Many venues must cope with periods of reduced water input due to regulatory constraints or local supply issues whilst also coping with intense and heavy rainfall at other times with the pitch always remaining playable, whilst promoting grass heath. Technology, such as under-pitch geocellular water management systems with passive irrigation capabilities, has helped stadia designers build resilience into stadia. These systems have been researched and tested in various climates including Northern Europe, desert climates and tropical environments.

The footprint of stadiums often extends beyond the stadium itself – what can be done in these areas to combat the effects of climate change?

Rod - Water scarcity is a global issue affecting billions of people, with the climate of a country playing a significant role in both the water resources available and sustainable development. Embracing more sustainable and resilient water management for stadia precincts by designing towards water negative developments can create pleasingly aesthetic, environmental and maintainable sports facilities.

Tom – A stadium precinct's overall footprint allows smart and innovative solutions to be used at scale. This can involve water storage below car parks, pavements, use of vegetation to act as wildlife corridors around the stadium and even using certain tree species to cool and clean the air in car parks. There is an expectation that we'll soon see the integration of blue and green infrastructure into stadia for maximum benefits, architecturally improving the stadium with the incorporation of vegetation on stadium walls or trees in planters at different levels. 

STRI have recently completed a design and build project of a blue-green roof on an office block in Manchester which could be replicated on to supporting structures around stadia. The blue-green roof was retrofitted onto an existing roof and utilised a geocellular storage system for sub-surface irrigation and to provide attenuation for the 100-year storm event. The wildflower roof benefits the area by offering a more diverse ecosystem both from the plants themselves and the flying insects that they attract such as bees and butterflies, in addition to the aesthetic benefit and the energy-saving properties of the roof.

About STRI: STRI are a global design, engineering and management consultancy, developing and delivering end to end sustainable plan, design, build, operate solutions for the built environment. Our expertise, founded within the design and management of green spaces within the sports sector, has and continues to deliver strategies for sports facilities and their surrounding infrastructure. For more information on sustainable water management, email enquiries@strigroup.com