Turning global lessons into local action on storm spill reduction

When heavy rainfall overwhelms a sewer network, wastewater can back up and spill beyond the system. These storm overflows can affect waterways, ecosystems and nearby communities, creating a significant challenge for water authorities and infrastructure providers.

The UK’s SSRP focused on investigating and reducing storm spills across multiple locations in the Yorkshire region.

We worked with Yorkshire Water and contractor partner Galliford Try to reduce sewer overflows across 15 locations. As the design partner, GHD coordinated delivery across the programme, balancing project requirements with real conditions on the ground, while maintaining clear collaboration between the client, contractor and project teams to support delivery against tight deadlines.

The programme highlighted the value of understanding local conditions and identifying the most appropriate solution for each site.

One of the strongest lessons from the programme was that reducing storm overflows cannot rely on a one-size-fits-all solution.

Our UK team focused on understanding what was driving spills at each location. In many cases, the challenge stemmed from capacity limitations, maintenance constraints and the scale of the sewer network. Heavy rainfall would push systems beyond their limits, triggering overflows that affected nearby areas.

We worked closely with Yorkshire Water and Galliford Try to assess each location and identify the most effective intervention. That approach meant aligning technical decisions with environmental goals and community outcomes, rather than applying a uniform design across all sites.

This approach strengthened project delivery as well as trust between stakeholders. It demonstrated that strong water infrastructure outcomes depend as much on coordination as they do on design.

That focus on site-specific thinking came through most clearly in the solutions delivered across the programme.

Where conditions allowed, the team prioritised nature-based and blue-green infrastructure approaches, while using more traditional solutions where they represented the most effective response.

At Temple Normanton, we introduced a sustainable drainage system to manage surface water more effectively. By slowing the flow before it reaches the treatment network, the solution reduces pressure on the sewer network and helps prevent overflows during heavy rainfall.

At Hill View Road, different site conditions required a different approach. We installed a concrete storage shaft to intercept excess flow during storm events. Instead of allowing wastewater to spill into the environment, the system captures flows and returns them to the sewer network once capacity is available.

These examples highlight key lessons that continue to inform water infrastructure delivery:

• Effective storm spill reduction starts with understanding the pressures affecting each site.
• Solutions should reflect local conditions, whether that means integrating nature-based systems or introducing engineered storage.
• Collaboration supports effective delivery and helps align outcomes with community expectations.

The programme’s approach has also received recognition through several Institution of Civil Engineers (ICE) awards and commendations for innovation, technical excellence, design and health and safety. 

Lessons from the SSRP have helped inform projects across regional Victoria.

While the context is different, the experience of working in smaller UK communities has provided valuable insight into how local conditions shape water challenges. That perspective has proven relevant in locations such as Bendigo and Castlemaine, where community needs and infrastructure constraints differ from larger metropolitan areas.

The programme emphasised the importance of targeted client engagement, including understanding local water authorities’ challenges and the context of the communities they serve.

There is also significant value in global knowledge sharing. Exposure to the UK’s focus on environmental design and nature-based solutions has added depth to how we approach water infrastructure locally. At the same time, Australian teams contribute their own insights and delivery experience, creating opportunities for knowledge sharing across GHD’s global network.

The SSRP reinforced three enduring lessons. Effective storm spill reduction starts with understanding the specific pressures affecting each site. Solutions are most effective when they respond to local conditions. Strong collaboration remains central to successful delivery.

These principles continue to shape how we deliver water infrastructure projects across Victoria. They support practical decision-making, stronger stakeholder engagement and infrastructure solutions designed to support long-term performance.

For organisations planning or upgrading water infrastructure, there is value in drawing on lessons from comparable projects while adapting them to local needs and community expectations. That is where our global experience makes a difference. It allows us to bring broader perspectives to complex water challenges and support better outcomes for communities and the environment.