Portage la Prairie ( /ˈpɔrtɨdʒ lə ˈprɛərɪ/) is a small city in the Central Plains Region of Manitoba, Canada. As of 2011, the population was 12,996. The area of the city was 24.67 square kilometres (9.53 sq mi). Portage la Prairie is located approximately 75 kilometres (47 mi) west of Winnipeg, along the Trans Canada Highway (located exactly between the provincial borders of Saskatchewan and Ontario), and sits on the Assiniboine River, which flooded the town persistently until a diversion channel north to Lake Manitoba (the Assiniboine River Floodway) was built to divert the flood waters. The city is surrounded by the Rural Municipality of Portage la Prairie.