Allumettes, Mattawa House, where west-bound canoes left the river and Fort Témiscamingue. From Lake Timiskaming a portage led north to the Abitibi River and James Bay. In the early 19th century, the Ottawa River and its tributaries were used to gain access to large virgin forests of white pine. A booming trade in timber developed, and large rafts of logs were floated down the river. A scattering of small subsistence farming communities developed along the shores of the river to provide manpower for the lumber camps in winter. In 1832, following the War of 1812, the Ottawa River gained strategic importance when the Carillon Canal was completed. Together with the Rideau Canal, the Carillon Canal was constructed to provide an alternate military supply route to Kingston and Lake Ontario, bypassing the route along the Saint Lawrence River. In 1907, the Department of Public Works published a map proposing a shipping lane through the Georgian Bay Ship Canal route, which would connect Georgian Bay to the Ottawa River through Lake Nipissing and the Mattawa River. Power generation A pulp and paper mill (at Témiscaming) and several hydroelectric dams have been constructed on the river. In 1950, the dam at Rapides-des-Joachims, was built, forming Holden Lake behind it and thereby submerging the rapids and portages at Deux Rivières. These hydro dams have had negative effects upon shoreline and wetland ecosystems, and are thought to also be responsible for the near extermination of American eels, which were once an abundant species in the river, but which are now uncommon. As an economic route, its importance was eclipsed by railroad and highways in the 20th century. It is no longer used for log driving, however, it is still extensively used for recreational boating. Some 20,000 pleasure boaters visit the Carillon Canal annually. Today, Outaouais Herald Emeritus at the Canadian Heraldic Authority is named after the river. Hydroelectric installations Hydroelectric installations on the Upper Ottawa (in downstream order): Lower Ottawa (in downstream order): * Ontario Power Generation operates generators 2, 3, 4, and 5 with a capacity of 96 MW; and Hydro-Québec operates generators 6, 7, 8, and 9 with a capacity of 89 MW. See also Lac Deschênes List of Ontario rivers List of crossings of the Ottawa River List of islands of Ontario#Ottawa River List of longest rivers of Canada Southern Ontario Eastern Ontario List of Quebec rivers Rivière des Mille Îles Rivière