Water Model Development for Freeze-Protected Water System in Iqaluit, Nunavut

Water for the City of Iqaluit, the capital city of the Canadian territory of Nunavut, is supplied from a nearby lake which feeds by gravity to a water treatment plant. Treated water is stored in a two-cell reservoir prior to distribution into seven independent water districts through an insulated and buried piping network. The water districts are unique because, in addition to insulated piping, each district has an independent recirculating water supply and water reheat system to provide freeze protection. This makes the hydraulic configurations of each district more complicated than a water system in warmer climates. Two of the districts are pressurized with independent booster pumphouses, and the remaining five districts are supplied by gravity from the reservoir. The City is advancing a project to develop a water model of its water distribution network which will provide a detailed understanding of the current system operations and provide a tool for system troubleshooting as well as planning for system upgrades and expansions. Model results will also be utilized for thermal analysis of the water districts. This will provide opportunities for optimization of the heat addition to the water supply to be explored which may provide some significant cost savings on the energy used to reheat the recirculating water. The first phase of the project has been completed with the objective of developing a working water model using all the system data based upon records of construction and operational data available for each of the seven water districts. This stage of the work has identified system deficiencies for maintenance and repairs. Phase 2 of the project will complete hydrant flow tests throughout the distribution system required to calibrate the water model.