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Modernizing hydraulic modeling software for sewer system analysis

    Written: Hannes Björninen & Kalervo Aho

    The Helsinki Region Environmental Services Authority (HSY) is one of the largest water and sewer utility in the Nordics. The wastewater and stormwater conveyance network in the HSY region is roughly 6 000 km in total, of which approximately 2900 km are wastewater sewers, 220 km combined and 2900 km of stormwater lines. HSY services around 1,2 million people living in Vantaa, Espoo, Helsinki, and Kauniainen municipalities and some neighboring cities.

    HSY began using software for sewer modeling in 1995. However, by 2012 HSY concluded that the current solutions needed to be improved in features and performance. In 2015, HSY began a project to develop a new sewer modeling system and unify its network data. The lead for this project has been Leena Sänkiaho, Development Engineer at HSY. After deciding to use an open-source solution, Leena’s team chose the EPA SWMM program as the base. They soon discovered that the EPA SWMM user interface was limited in usability and analysis capabilities, so the search for new, improved software began.

    Communication and collaboration with Fluidit team throughout the project has been very proactive and engaging.

    Leena Sänkiaho
    Development Engineer HSY

    In 2020, the team began the development project for the new combined sewer model. HSY selected Fluidit Storm due to its SWMM-based platform, flexible user interface, and popularity among consultants in Finland. While using Fluidit Storm more extensively, Leena’s team thought that the software is intuitive and allows for customization of visualizations and user interface that fits their specific needs. The three-day intensive software training provided by Fluidit was very welcome to facilitate a smooth start. Communication and collaboration with the Fluidit team have been very proactive and engaging throughout the project, Leena points out.

    In Fluidit Storm, all data is timestamped, aligning with measurements and SCADA data smoothly. Leena aims to improve the use of real-time data sources at HSY to enable the transition to real-time combined sewer overflow analysis, according to HSY’s long-term ambitions. The design team also uses Fluidit Storm for capacity reviews, network sizing, and scenario planning. The fact that HSY has the internal capacity to use the software increases their knowledge of the whole system, which is beneficial in solving complex problems faced at the utility.

    Fluidit Storm is compatible with other ICT systems used at the utility, which facilitates a relatively straightforward transition to real-time network simulations. The real-time simulations were piloted at city-scale in 2022 in a project funded by Ministry of the Environment through Water Protection Programme. HSY’s intention is to adopt the real-time simulation system for operational Combined Sewer Overflow (CSO) estimation and reporting.

    Over the last few years, HSY has successfully implemented the Fluidit software for their separate and combined sewer modeling needs. The team, led by Leena Sänkiaho, found Fluidit a familiar and efficient choice. According to Leena, the development project, led by Fluidit’s Hannes Björninen and Pedro Almeida, was “very agile”, and working with them “has been a great mutual learning process.” Leena’s team felt Fluidit was excellently present during the project with close communication.

    More information:

    1. Publication 2022: Björninen, Almeida, Sänkiaho – Estimate combined sewer overflows in real-time at a city scale: Case Helsinki;