Transforming sewer system analysis by automated simulations and CSO insights.

The Challenge

Managing one of the largest combined sewer networks in the Nordic region, Helsinki Region Environmental Services Authority (HSY) faced a recurring bottleneck: too much time spent on routine work, too little left for actual analysis. Every three months, external consultants would rerun network simulations, manually produce overflow reports, and hand over the results — a slow and costly cycle that left HSY dependent on third parties even for basic, recurring tasks.

We spoke with Hanna Riihinen, Development Engineer at HSY, about how they transformed their sewer network management using Fluidit.

“In the past, we were essentially paying consultants to repeat the same tedious reporting process each quarter. Due to the burden of reporting, understanding why overflows happen and how to mitigate them did not get the focus needed.”

Transformation

The transformation happened in stages. First, HSY migrated the network model onto the Fluidit platform and began running simulations in-house. That alone reduced dependence on consultants and brought the team closer to their own data.

The real step change came when simulation and reporting were automated end-to-end with Fluidit’s real-time combined sewer system implementation. What had previously required weeks of consultant hours and manual oversight now runs with minimal intervention. Instead of spending time on calculations and manual analysis, the team at HSY could spend its valuable time interpreting results and making decisions.

Benefits

Saving time and costs

Routine overflow reporting is now largely automated. The shift from paying consultants to repeat work to paying a license fee for a platform HSY controls has delivered clear, ongoing savings in both consultant fees and internal working hours, even without formal hour tracking.

A deeper understanding of the sewer system

With the entire combined sewer network modeled in one place, HSY can quickly assess the system-wide impact of infrastructure changes, emergency situations, and rehabilitation projects. For example, when major works were planned for the Esplanade area, including separating combined sewers and building a new sewer tunnel, the model enabled tracing where potential CSO problems could shift.

Reinvesting time in systemic analysis

Time freed from routine calculation and reporting has been reinvested in cause-and-effect analysis: understanding why overflows occur and how the network behaves as a whole. This kind of systemic thinking simply was not possible before.

“Network data alone is not enough to understand a complex sewer system at the scale of HSY. You need the right tools for the job, and Fluidit has provided exactly that.”

The Partnership

Hanna highlights that the collaboration with Fluidit has been straightforward and reliable: “When real-time model calculations encounter issues, Fluidit’s dedicated engineer support responds quickly. Not only is the response prompt, but the team also understands our systems in detail.”

HSY models extensively in-house, and Fluidit embraces this approach as a preferred way to solve problems effectively. Fluidit’s expert support is available for the most complex modeling challenges and development work, ensuring HSY stays current with new capabilities without having to chase them independently. Hanna finds it practical to shape development priorities jointly with Fluidit, as this way HSY’s operational needs feed directly into broader product decisions.

“Because Fluidit is advancing the platform internationally, we benefit from this development even with our own limited time for model work. It keeps us on the frontier without having to be there alone.”

If you’re interested in learning how Fluidit Storm can elevate your separate sewer, combined sewer, or stormwater capabilities, reach out to us at sales@fluidit.com or fill out the contact form.