Hydrologic Performance of Permeable Pavement as an Adaptive Measure in Urban Areas: Case Studies near Montreal, Canada

The infiltration capacity of permeable interlocking concrete pavement (PICP) was characterized on five sites located in the greater Montreal area (Canada). Surface infiltration rates up to more than 20,000 mm/h were observed, even in winter at subzero temperatures (°C). At one of the five monitored sites, rainfall and flow at the outlet were monitored for 12 months. This monitoring revealed peak flow delays ranging from 4 min to 4 h 42 min and runoff reductions ranging from 26% to 98%, depending on the rainfall event. These rainfall and flow data were used to calibrate a PICP hydrologic model that was then used to quantify the impact of implementing PICP in four real urban watersheds. For an eight-year rainfall series, simulations showed a reduction in volume (65%) and duration (21%–48%) of overflows in the two combined sewer systems, a reduction in peak flow (6%–45%) and volume (mean 30%) at the outfall of the two separate systems, and a reduction in surface flooding duration (24%–81%) for the four sewer systems.