Urban Land Subsidence: A Case Study in Richmond, British Columbia

Groundwater extraction can cause soil to consolidate and land to subside. Land subsidence increases relative sea-level rise and exacerbates inundation hazards for coastal cities. The City of Richmond is a low lying floodplain, on average 1 m above mean sea level, with increasing development due to urbanization. This makes it imperative that Richmond maintains its high water table to prevent subsidence. Furthermore, Richmond’s high water table necessitates dewatering at excavation sites in order to proceed with construction processes. Examining the impacts of dewatering based subsidence in Richmond, on a neighbourhood scale, highlights why groundwater levels should be maintained on a city-wide scale. Richmond can evaluate management practices utilized globally that contribute to the maintenance of the groundwater table to further mitigate subsidence and to combat potential effects of climate change.