Ausable River (Lake Huron)

Mouth of the Ausable River near Port Franks

The Ausable River is a tributary of Lake Huron in the Canadian province of Ontario.

The Ausable River rises near the settlement of Staffa in the municipality of West Perth in Perth County. From there it flows past in a predominantly westerly direction through the villages of Exeter, Ailsa Craig and Nairn. In the Arkona Ausable River turns north.

The river at the lower Ausable River has changed significantly in 1875. Originally flowed the Ausable River in an elongated loop north to Grand Bend and then parallel to the shore of Lake Huron south again and culminated in Port Franks in Lake Huron. The construction of a drainage canal, called The Cut, the river water is then passed directly to Port Franks. The old riverbed a fraction of the water only flows to Grand Bend, which also has a drainage channel directly into Lake Huron. Between Grand Bend and Port Franks of the Old Ausable Channel is now the original lower reaches of the river.

The Ausable River has a length of about 240 km. Its catchment area covers 1142 km ².