Sewerage network modelling in Latvia, use of InfoWorks CS and Storm Water Management Model 5 in Liepaja city

The existing partially combined sewerage system in the city of Liepaja, Latvia, is in a poor structural condition and hydraulic overloading causes flooding and pollution. As part of a wider project to upgrade water services in the city, supported by the European Union (EU) cohesion fund (CF), a mathematical model of the system was constructed and verified. In determining appropriate software for use, two key objectives had to be considered: (i) fast model construction to allow upgrading works to be designed and implemented within the timeframe given in the EU Financing Agreement and (ii) provision of an affordable design and assessment tool for future use by the water company. To meet these objectives, InfoWorks CS software was used for model building and verification and the model was subsequently exported to freely available Storm Water Management Model (SWMM) 5. The predictive results of the two models were compared with validate the SWMM5 model.