We’re delighted that Stockport Interchange has been recognised at the 2026 susdrain Awards, winning the Regeneration & Retrofit: Public Buildings category before going on to be named the Overall Winner of the evening.

The award recognises an ambitious project that has transformed a key gateway into Stockport town centre, from a drab grey bus interchange into a living and breathing park above a transport interchange, demonstrating how sustainable drainage can sit at the heart of major urban regeneration.

At the heart of the scheme is EPG’s blue roof design, which helps transform the roof park from public realm into working climate-resilient infrastructure. Working alongside United Utilities and the wider design team, EPG helped ensure the roof park does far more than provide public space. It stores and slows rainfall, supports passive irrigation, reduces peak runoff and helps create a greener, cooler and more resilient town-centre environment.

Through the project, EPG delivered the SuDS design from RIBA concept stage through to detailed design, helping integrate water management into the wider vision for the development. A key element of the project was incorporating a Grade II* listed viaduct into the new park. Alwyn Hughes, Structural Waterproofing Manager, and his team played a fundamental role in integrating the existing viaduct into the structural waterproofing design, which was a significant technical challenge and an important part of the project’s success.

For us, that’s what makes this recognition particularly rewarding.

Stockport Interchange isn’t simply an award-winning drainage scheme. It’s a project that demonstrates what can happen when sustainable drainage is treated as an opportunity to create better places and enhance our natural environment.

Phil Williams, Managing Director of EPG, said, “I’ve been lucky enough to work on Olympic arenas, elite sports venues and huge giga-projects where the numbers are enormous. But this park in Greater Manchester might be my favourite. We talk a lot in the UK about the difficulty of delivering major infrastructure. Here is one that has been delivered. And it is now giving something back to the community, including an estimated £16m of natural capital value. Some projects are impressive because they are big. Some are impressive because they are complicated. This one is special because it is useful, generous and visible.”

Putting SuDS at the centre of regeneration

Urban regeneration projects are rarely straightforward. Constrained sites, existing infrastructure, competing stakeholder priorities and increasing climate pressures all create challenges that require careful thought and collaboration.

Stockport Interchange was no exception.

The project sought to deliver a modern transport hub, new homes, public realm improvements and enhanced green space, all within a complex urban environment. The challenge was not simply to manage water, but to use water management as part of a wider vision for regeneration.

The completed scheme includes a 4,000m² publicly accessible roof park, designed to manage a 1-in-100-year storm event plus a 40% climate change allowance. The blue roof system provides 85mm of attenuation storage and achieves a greater than 95% reduction in peak runoff rates, demonstrating how sustainable drainage infrastructure can deliver measurable performance alongside wider community benefits.

Instead of relying solely on traditional underground infrastructure, the scheme embraces sustainable drainage principles, integrating blue-green infrastructure throughout the development. This approach helps slow, store and manage rainfall while creating an attractive and functional environment for the people who use it every day.

As towns and cities continue to adapt to the realities of climate change, projects such as Stockport Interchange provide an important blueprint for the future.

They show that sustainable drainage is not simply about managing water; it’s about creating places that are more resilient, more attractive and better equipped to support communities for generations to come.

To see Stockport Interchange recognised with both a category award and the Overall Winner title is a fantastic achievement for everyone involved.

Congratulations to United Utilities and the entire project team on this well-deserved recognition.

We’re delighted that Stockport Interchange has been recognised at the 2026 susdrain Awards, winning the Regeneration & Retrofit: Public Buildings category before going on to be named the Overall Winner of the evening.

The award recognises an ambitious project that has transformed a key gateway into Stockport town centre, from a drab grey bus interchange into a living and breathing park above a transport interchange, demonstrating how sustainable drainage can sit at the heart of major urban regeneration.

At the heart of the scheme is EPG’s blue roof design, which helps transform the roof park from public realm into working climate-resilient infrastructure. Working alongside United Utilities and the wider design team, EPG helped ensure the roof park does far more than provide public space. It stores and slows rainfall, supports passive irrigation, reduces peak runoff and helps create a greener, cooler and more resilient town-centre environment.

Through the project, EPG delivered the SuDS design from RIBA concept stage through to detailed design, helping integrate water management into the wider vision for the development. A key element of the project was incorporating a Grade II* listed viaduct into the new park. Alwyn Hughes, Structural Waterproofing Manager, and his team played a fundamental role in integrating the existing viaduct into the structural waterproofing design, which was a significant technical challenge and an important part of the project’s success.

For us, that’s what makes this recognition particularly rewarding.

Stockport Interchange isn’t simply an award-winning drainage scheme. It’s a project that demonstrates what can happen when sustainable drainage is treated as an opportunity to create better places and enhance our natural environment.

Phil Williams, Managing Director of EPG, said, “I’ve been lucky enough to work on Olympic arenas, elite sports venues and huge giga-projects where the numbers are enormous. But this park in Greater Manchester might be my favourite. We talk a lot in the UK about the difficulty of delivering major infrastructure. Here is one that has been delivered. And it is now giving something back to the community, including an estimated £16m of natural capital value. Some projects are impressive because they are big. Some are impressive because they are complicated. This one is special because it is useful, generous and visible.”

Increasing rainfall intensity and more frequent storm events are placing growing pressure on existing drainage systems. School sites, which are typically characterised by large impermeable areas, limited green space and ageing drainage infrastructure, are particularly vulnerable to exceedance and surface water flooding.

Across six schools in Essex, these pressures were already being experienced, with frequent flooding, surcharge of existing drainage systems and disruption to normal school operations.

Working in partnership with Essex County Council, The Environmental Protection Group (EPG), alongside Carrick Construction, delivered a coordinated Design & Build service of retrofit sustainable drainage systems (SuDS). The schemes were designed to attenuate surface water runoff, reduce peak discharge rates and improve overall site drainage resilience.

Site-Specific Flood Risk Assessment

Each school presented unique drainage characteristics and constraints. Large roof areas and hardstanding generated rapid runoff, while limited infiltration potential and restricted outfall capacity contributed to localised flooding during heavy rainfall events.

To inform the design process, EPG undertook detailed site assessments including:

Topographical surveys to define overland flow pathways and levels

Drainage investigations to identify existing network configuration and condition

Hydraulic modelling to assess runoff volumes and discharge requirements

This information was used to understand existing exceedance routes, identify critical low points and determine opportunities for attenuation and infiltration. Designs were then tailored to each site, which is essential for successful SuDS retrofit within constrained school environments.

Sustainable Drainage Design

The design approach focused on managing runoff close to the source and reducing the rate and volume of discharge to the existing drainage network.

Key SuDS components included:

Rain gardens – providing a visually engaging surface storage and filtration component.

Bioswales – slowing conveyance and temporarily storing surface water flows

Permeable surfacing – reducing rainwater runoff and flash flooding risk

SuDS planters – intercept and attenuate downpipe flows in constrained areas

Rainwater butts – offering rainwater re-use for irrigation

Rainwater Marble runs – drive early curiosity and passive learning

Green walls – promoting biodiversity and providing visual improvements

These features work together to collectively slow runoff, provide temporary storage and promote infiltration where feasible.

The designs prioritised surface-based SuDS features to maximise cost-benefit, provide passive low-maintenance solutions, improve biodiversity, and offer engagement opportunities within the school curriculum.

SuDS Retrofit in Operational School Sites

All works were delivered within live school environments, requiring careful consideration of programme, access and safeguarding requirements. Construction activities were phased to minimise disruption to school operations and maintain safe access for pupils and staff.

Key delivery constraints included:

Working around term-time operations to minimise disruption

Safeguarding and secure site separation

Restricted working areas and access routes

Coordination with existing underground services

Close collaboration between EPG, Carrick Construction and Essex County Council ensured that designs were buildable, safely implemented and aligned with operational requirements. This integrated delivery approach is critical when retrofitting SuDS within constrained educational settings.

Additional Benefits of SuDS Retrofit

While the primary objective was the reduction of surface water flood risk, the SuDS features also delivered wider environmental and educational benefits, including:

Improved water quality through vegetated filtration and sediment capture

Increased biodiversity through planting and habitat creation

Enhancement of external learning and amenity spaces

Special Educational Needs (SEN) tailored planting to offer sensory spaces for students

Visually engaging interventions to drive early curiosity and passive learning.

The installed rain gardens and landscaped SuDS features now form visible and functional elements of the school environment, supporting both drainage performance and educational value.

Scalable SuDS Retrofit Approach

This project demonstrates how SuDS retrofit can be successfully implemented across multiple school sites with varying constraints. By combining site-specific assessment, surface-based attenuation and collaborative delivery, effective reductions in surface water flood risk were achieved.

As rainfall intensity and urban drainage pressures continue to increase, retrofit SuDS schemes such as these provide a practical and scalable approach to improving resilience across existing school estates, while delivering additional environmental and community benefits.

The Environmental Protection Group strengthens Board to enhance delivery for clients and support next phase of growth

The Environmental Protection Group (EPG) has announced the expansion of its Board of Directors, marking a significant milestone in the consultancy’s continued growth and long-term development, further strengthening its ability to support clients with complex development challenges across the UK.

Founded by Paul Culleton and Diane Leigh and shortly after joined by Steve Wilson, EPG was established at a time when sustainable drainage systems (SuDS) and vapour and ground gas mitigation were not widely recognised within UK development. From the outset, the founders challenged conventional practice, helping to shape industry understanding and setting a strong technical foundation that continues to underpin the business today.

Since becoming part of STRI Group, EPG has experienced sustained growth, expanding from a team of ten to nearly 40, following the recent acquisition of Hafren Water. This has added further depth to its expertise and ability to provide agile responses to client needs.

To support the next phase, EPG has appointed three new Directors to its Board:

Phil Williams, Managing Director
Amy Juden, Director
Leo Phillips, Director

Phil Williams commented, “As EPG moves forward, the strengthened Board provides a robust platform to support continued growth, technical excellence and long-term value for clients across geoenvironmental engineering, structural waterproofing and sustainable water management. We have a great team surrounding us and we’re looking forward to what the future holds.”

These appointments recognise the leadership, technical capability and long-standing commitment Phil, Amy and Leo have demonstrated in helping to build and shape the business, ensuring clients continue to benefit from technical leadership, responsive service and ongoing innovation.

The Environmental Protection Group strengthens Board to enhance delivery for clients and support next phase of growth

The Environmental Protection Group (EPG) has announced the expansion of its Board of Directors, marking a significant milestone in the consultancy’s continued growth and long-term development, further strengthening its ability to support clients with complex development challenges across the UK.

Founded by Paul Culleton and Diane Leigh and shortly after joined by Steve Wilson, EPG was established at a time when sustainable drainage systems (SuDS) and vapour and ground gas mitigation were not widely recognised within UK development. From the outset, the founders challenged conventional practice, helping to shape industry understanding and setting a strong technical foundation that continues to underpin the business today.

Since becoming part of STRI Group, EPG has experienced sustained growth, expanding from a team of ten to nearly 40, following the recent acquisition of Hafren Water. This has added further depth to its expertise and ability to provide agile responses to client needs.

To support the next phase, EPG has appointed three new Directors to its Board:

Phil Williams, Managing Director
Amy Juden, Director
Leo Phillips, Director

Phil Williams commented, “As EPG moves forward, the strengthened Board provides a robust platform to support continued growth, technical excellence and long-term value for clients across geoenvironmental engineering, structural waterproofing and sustainable water management. We have a great team surrounding us and we’re looking forward to what the future holds.”

These appointments recognise the leadership, technical capability and long-standing commitment Phil, Amy and Leo have demonstrated in helping to build and shape the business, ensuring clients continue to benefit from technical leadership, responsive service and ongoing innovation.

The Environmental Protection Group (EPG) is pleased to announce the acquisition of Hafren Water, a respected environmental consultancy specialising in hydrology and hydrogeology services.

This acquisition marks another exciting milestone in EPG’s continued growth, with Hafren Water’s hydrogeology expertise complementing EPG’s existing services and strengths with the ability to deliver integrated water and geoenvironmental management solutions across the UK and beyond.

Hafren Water brings a highly skilled team of specialists with extensive experience in hydrology, hydrogeology, water resource management, and flood risk assessment. Their technical excellence will further enhance EPG’s elite capabilities, enabling the development of groundwater and piling works risk assessments in addition to risk assessments for infiltration systems on high-risk sites, providing guidance from inception to completion of a project.

The acquisition introduces new clients and sector opportunities for EPG, especially within the quarrying industry, where Hafren Water has built a strong reputation.

Hafren Water will continue to operate under its well-respected brand, maintaining its base in Shrewsbury, and will work closely with EPG to share knowledge, expertise, and to continue delivering excellence for clients. The two businesses are committed to long-term collaboration, stability, and sustainable business development for both brands.

“We’re delighted to welcome Hafren Water into the EPG family,” said Phil Williams, Director of EPG. “Their hydrology and hydrogeology expertise will significantly strengthen our services and help us deliver even greater value to our clients. This acquisition is about long-term growth and building strong foundations for the future.”

“Joining EPG allows us to build on our existing strengths while collaborating to expand our capabilities and reach,” added Chris Leake, Director of Hafren Water. “We’re excited about the opportunities this partnership will bring for our clients, our people, and the wider industry.”

EPG looks forward to a successful partnership with Hafren Water, expanding its ability to deliver innovative, sustainable, and technically robust environmental solutions.