In 2005, the Province of Ontario implemented its Ecological Framework for Recreational Fisheries Management, a component of which was the establishment of standardized, long-term monitoring of the province’s fisheries resource, referred to as Broadscale Monitoring. The Broadscale Monitoring program was initiated in 2008, with the aim of collecting detailed fisheries and water quality information on a five-year cycle from hundreds of lakes across the province. The water chemistry data are available for download here. From 2008 to 2019, spring water chemistry samples were obtained from hundreds of lakes in Ontario, ranging from 5 to 250,000 hectares in size using a standard sampling protocol. Water samples were collected by the Ministry of Northern Development, Mines, Natural Resources and Forestry. Water chemistry analyses were performed by the Ministry of Environment, Conservation and Parks