Lake Onega is relatively cold, with temperatures below for half of the year and average summer temperatures of about . The catchment area of drains into the lake via 58 rivers and more than 110 tributaries, including the Shuya, Suna, Vodla, Vytegra and Andoma. The only outgoing River Svir, which marks the southern boundary of Karelia, runs from the southwestern shore of Lake Onega to Lake Ladoga and continues as the Neva River to the Gulf of Finland. The White Sea–Baltic Canal runs through the lake from the White Sea to the Baltic Sea. The Volga–Baltic Waterway connects Onega Lake with the
Port Phillip Geelong at Corio Bay in 1838. Today Port Phillip is the most densely populated catchment in Australia with an estimated 4.5 million people living around the bay; Melbourne's suburbs extend around much of the northern and eastern shorelines, and the city of Geelong sprawls around Corio Bay, in the port's western arm. Port Phillip Bay formed between the end of the last Ice Age around 8000 BCE and around 6000 BCE, when the sea-level rose to drown what was then the lower reaches of the Yarra River, vast river plains, wetlands and lakes. The Yarra and other tributaries flowed down