Following a literature review conducted by the Urban Forest Research Chair as part of the development of the Guide d’implantation des arbres en zone urbaine à proximité de réseaux for the CERIU (Centre of Expertise and Research in Urban Infrastructure), we identified a significant lack of knowledge regarding conflicts between tree roots and underground networks. In fact, there is a substantial lack of quantitative data, with existing information largely limited to sewer systems.

Although interventions on underground infrastructure are very frequent, we have no information indicating whether trees are potentially involved in these interventions. As a result, we are unable to determine the extent to which trees may be responsible for certain issues affecting underground public utilities. In the absence of data, current best-practice recommendations are largely based on opinions—often widely repeated—without empirical evidence regarding the main factors involved (distance, species, type of infrastructure, installation method, etc.). Furthermore, without information on the frequency of these situations and their causes, we cannot properly understand them or assess them objectively in order to identify options to minimize the risk of conflicts.

These issues are becoming increasingly important as municipalities implement ambitious tree-planting programs aimed at increasing canopy cover, given the many benefits trees provide to cities and their residents, including climate change adaptation and the reduction of ambient temperatures, with direct impacts on human health.

This project therefore aims to develop and implement a web-based platform (Rhizo portal) that could be used by municipalities and urban technical network (UTN) companies to evaluate future interventions, assess the potential for conflicts between tree roots and municipal and/or urban technical networks, and identify ways to mitigate them. The evaluations generated by the platform would be based on a predictive model developed from identifying the factors most likely to cause conflicts between tree roots and infrastructure, as well as those that help minimize them. The project’s results would also be used to update the Guide d’implantation des arbres en zone urbaine à proximité de réseaux.