The 1959 closure of electric transit in Ottawa coincided with the opening for service of the international hydroelectric power dam on the St. Lawrence River, southeast of Ottawa. For over 40-years, Ottawa Electric Railway (OER) owned and operated a small hydroelectric generating installation on the south side of the Ottawa River, in a channel located south of the main hydroelectric power dam in the river. OER had access to local, low-cost electric power.

Prior to the opening of the international hydroelectric power dam, Ontario Hydro had given notice that all small hydroelectric power dams across Eastern Ontario were to be taken out of service, including the dam operated by OER. OER would subsequently have had to pay commercial power rates for electric power. Instead, OER management handed the transit operation over the the City of Ottawa (Ottawa Transportation Commission) that made the decision to discontinue electric transit in 1959.

The City of Ottawa took over the OER in 1948 -- more than 10 years before the system was shut and dismantled