Green drainage infrastructures (GDI) is increasingly deployed in urban areas to manage stormwater runoff at the source. However, its effects on the subsurface environment, particularly on groundwater levels and solute transport, remain poorly documented. This thesis aims to characterize the influence of small-scale GDI on groundwater in the urban context of Montreal and Laval.
Three experimental sites (Chabanel-Galinée, Waverly-Mozart and Berlier-Bergman), each equipped with a roadside GDI, were instrumented with piezometers fitted with probes measuring water level, electrical conductivity and temperature at five-minute intervals. Guelph permeameter tests and variable-head tests in piezometers, combined with grain-size analyses, were used to characterize the hydrogeological properties of the soils. A 2D numerical model based on Richards’ equation was developed in COMSOL Multiphysics and calibrated using data from the Chabanel-Galinée site.
Results show that GDI exerts a measurable influence on local piezometry. Water level rises of up to +130 cm were recorded beneath the GDI during major rainfall events, compared with smaller amplitudes in the control zone. Electrical conductivity monitoring revealed variable patterns across sites : at Berlier-Bergman and Waverly-Mozart, values in the control zone were higher than those measured near the GDI, whereas the opposite trend was observed at Chabanel-Galinée. In the absence of hydrochemical analyses, it is not possible to confirm the nature of the solutes or to attribute electrical conductivity variations specifically to the GDI. The numerical model reproduces the essential dynamics of the system with RMSE values of 0.134 to 0.184 m, validating the modeling approach.
These results help fill the gap in field data on interactions between GDI and the urban subsurface and highlight the need to integrate hydrogeological considerations into the design and regulation of such facilities.
Farley, R.-A. (Author),
Duhaime (Supervisor) &
Dubé (Co-supervisor),
16 Sept 2026Student thesis: Master's thesis › Master in Engineering: Construction Engineering