One hundred years of drainage development in the Holland Marsh, Canada, and implications for long‐term sustainability

Abstract

AbstractThe low‐lying peatlands of the Holland Marsh are intensively cultivated with high‐value vegetable crops, worth some $450 million Canadian annually. This high productivity is due to the fact that there have been significant investments to empolder the marsh, through the construction of dykes, embankments, canals, ditches, tile drainage, and installation of pumping stations. However, attention must be paid to the long‐term environmental sustainability of the Holland Marsh, given the high phosphorus loads and eutrophication in Lake Simcoe, the principal drainage outlet for the agricultural run‐off from the marsh. It is important that non‐point source pollution be reduced and drainage water quality better managed. In addition to agro‐environmental best management practices, adoption of controlled drainage, and improved drainage water pumping strategies are recommended. These could help achieve the P reduction target established by the government of Ontario and the Lake Simcoe Region Conservation Authority.