Monitoring and modeling drinking water temperature during summer heatwaves: understanding the effect of green spaces vs. heat islands in a Canadian city

“Urbanization has increased the importance of urban heat islands worldwide. Higher air temperature, especially during summer heat waves, increases the soil’s surface and subsurface temperature in city hotspots (Zhou, Wang et al. 2017, Alexander 2021). Blokker and Pieterse‐Quirijns (2013) have previously developed a model that uses the soil temperature data to predict the water temperature in the water distribution system (WDS). They found that the water temperature at a 1-meter depth reaches its surrounding soil temperature and can exceed the Dutch regulatory threshold of 25ºC during Summer. While the depth of pipes in Canadian WDSs ( 2m) is higher than the Dutch WDSs (1m), it is still unknown to what extent the water temperature in these deeply buried pipes will be affected by its surrounding soil during hot periods in summer. Elevated temperatures can accelerate the chlorine decay rate, increase the risk of bacterial regrowth, and cause regulatory non-compliance in some jurisdictions. Therefore, this study aims at understanding through field monitoring and modeling whether summer heatwaves impact the water temperature at a 2-meter depth. We also seek to understand the cooling effect of green spaces (cool islands) vs. the warming effect of heat islands on drinking water temperature in the urban water supply systems during hot periods. This study is performed on a full-scale network in a city in Southern Quebec (Canada). To our knowledge, no study has yet studied the cooling/warming effect of land coverage in urban water systems through monitoring and modeling.”

(Citation: Absalan, F., Hatam, F., Blokker, E.J.M., et.al. – Monitoring and modeling drinking water temperature during summer heatwaves – 19th International Computing & Control for the Water Industry Conference, 4-7 September 2023)