On Sunday, Wellington County Ontario Provincial Police (OPP) were called to the lake around 5 p.m. for reports that a swimmer is in danger. OPP told CTV News the person was about 30 feet from shore. Police aviation and underwater search and rescue teams, along with the Guelph and Grand Valley fire departments, are all assisting in the search. Officials say the search will continue until dark and, if the person is not found by then, will resume Monday morning. The public is asked to avoid the Guelph Lake area. Anyone with information about the incident is asked to contact the Wellington County OPP.