From February 2011 to December 2012, the Tallinn Water Company, AS Tallinna Vesi (ASTV), aimed at improving the previous hydraulic model creation procedures so that the model can be operatively updated through the available geographic information system, client information system (Navision), supervisory control and data acquisition system (SCADA). The goal of the project was to analyse various model building alternatives so that data reload can be easily managed by ASTV. The model rebuild is necessary because of continuous changes in the water network (pipe renewals, new developments, demands, etc.). The project was divided into two phases. Phase 1 was mainly about hydraulic network model build-up to the pre-calibrated state where all possible data sources were created and data are loaded into hydraulic modelling software. Phase 1 was finished in May 2012. Phase 2 started in summer 2012, and included pressure measurement point selections, data validation and model calibration. The final production model provides the possibility of using the model for real decision-making.