Partnering with Submergent to raise the level

---

In a highly technical field like hydrologic and hydraulic modelling, we help engineers walk the fine line between the outcomes they need, the minimum requirements and the available funds. Of course, the proof is always in the long-term outcomes the modelling delivers – how well infrastructure performs over a few decades or the accuracy of a region’s flood forecasting, for example.

Navin Weeraratne works in civil engineering for water and environmental infrastructure. He relies on Submergent’s modelling – and he knows great work when he sees it. It’s part of why, when he started his business, Weir Consulting, he made sure the Submergent team would be on hand for projects. 

“Their analytical work optimises our designs to make them fit for purpose,” he says. “They’re the best at what they do.” 

Designing for long-term resilience 

Submergent wants to get things right, which sometimes means challenging the status quo or asking difficult questions. 

Stormwater infrastructure is typically designed to offer a level of service of up to 10 years, but has a design life of up to 100 years. In contrast, best practice considers the network’s performance over its full lifespan. Navin explains that Submergent’s models look beyond the minimal levels of service and understand the operational realities of network infrastructure, along with the unique characteristics and operational risks of each system.

“We are building infrastructure that is used for 50 to 100 years… modelling undertaken to minimum requirements only looks for five to 10 years max. That means risks associated with things like blockages or overflows are often missed or left for separate assessment. When Submergent builds a flood model, you can rest assured they’ve thought about the most critical scenarios.”

“Models based on minimum requirements are comfortable – they’re familiar, repeatable and ‘compliant’. Yet they risk missing the critical scenario: how a network will deliver over its useful life.”

It can have a profound impact when Submergent makes even very small changes to tailor modelling to each project.

“You’re dealing in the edges, but you’ve got to get those right, because we are building a city, a town, a new residential development,” says Navin.

Best fit, not overengineering 

Submergent’s precision doesn’t mean projects are over-engineered. Quite the opposite. It understands the nuances, so it can more accurately assess risk. This means it doesn’t need to take a highly conservative – and therefore expensive – approach. 

“A more detailed model allows us to better understand the risks from more accurate flood levels and more accurate flow velocities, so we can design for those specific effects.”

Much of Weir and Submergent’s work comes from organisations looking to bring down the cost of infrastructure projects, scoped using other models. 

“They bring us in to optimise designs, so they’re the best fit, not overengineered,” explains Navin. “So, you can basically pay Submergent $20,000 and save $20 million.”

Navin points to the recent Inga Road Bridge upgrade as an example. Initial plans included raising the bridge above potential flood levels. Submergent’s modelling demonstrated that this would be a wasted investment. 

“Raising the bridge would keep it clear in a flood, but the roads either side would be under water – the bridge would still be unusable.” 

Using Submergent’s modelling, Weir could argue that this particular new bridge design added unnecessary cost. 

A partnership built on precision

For Navin, the partnership with Submergent works because both businesses bring deep, complementary expertise. Submergent’s analytical insight strengthens Weir’s engineering design, creating a multidisciplinary team of specialists. Because the two companies work from the same office, they enjoy a smooth flow of information, sharing expertise to add to the work of both teams. 

Navin says together they deliver infrastructure that serves communities over generations.

“Our clients get the benefit of both worlds: the analytic depth and the design capability – specialists working together can deliver more.”

_______