The Agnes River is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in the Lake Huron

Lake Huron

Lake Huron is one of the five Great Lakes of North America. Hydrologically, it comprises the larger portion of Lake Michigan-Huron. It is bounded on the east by the Canadian province of Ontario and on the west by the state of Michigan in the United States...

 drainage basin

Drainage basin

A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

 in Unorganized Sudbury District in Northeastern

Northeastern Ontario

Northeastern Ontario is the region within the Canadian province of Ontario which lies north and east of Lakes Superior and Huron.Northeastern Ontario consists of the districts of Algoma, Sudbury, Cochrane, Timiskaming, Nipissing and Manitoulin; and the single-tier municipality of Greater...

 Ontario

Ontario

Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

, Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

.

The river begins at an Sinaminda Lake and flows southeast to its mouth at the Spanish River

Spanish River (Ontario)

The Spanish River is a river in Algoma District, Sudbury District and Greater Sudbury in Northwestern Ontario, Canada. It flows in a southerly direction from its headwaters at Spanish Lake and Duke Lake to its mouth at the North Channel on Georgian Bay, Lake Huron just outside of the community...

, which flows to the North Channel

North Channel (Ontario)

The North Channel is the body of water along the north shore of Lake Huron, in the Canadian province of Ontario. It is bordered on the east by Georgian Bay, on the west by the St. Marys River, to the north by the eastern Algoma District and to the south by the islands of Manitoulin, Cockburn,...

 on Lake Huron. The outflow from Sinaminda Lake is controlled by the Sinaminda Dam, owned by Domtar

Domtar

Domtar Corporation is the largest integrated producer of uncoated freesheet paper in North America and the second largest in the world based on production capacity, and is also a manufacturer of papergrade pulp....

; water from the lake reservoir is used to provide a regulated flow to hydroelectric

Hydroelectricity

Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...

 generating stations owned by Vale Inco further downstream on the Spanish River. The mouth of river is a glacially-formed fluvial delta

River delta

A delta is a landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river...

.

A stand of old-growth forest called the Agnes River Old Pine is located in the Agnes River drainage basin.