The Toulnustouc River flows through the unorganized territory of Rivière-aux-Outardes. The north branch, Rivière Toulnustouc Nord, leaves
Dechêne Lake about east of the
Manicouagan Reservoir. It flows southeast through Lac Bardoux and Lac Brûleé, then turns south to
Lac Caron, where it is joined by the northeast branch. The
Northeast Toulnustouc River is fed by the
Petit lac Manicouagan, and flows southeast and then south before turning west into Lac Caron. The
Cartier Railway runs beside it for most of its length. The combined Toulnustouc River flows SSE through
Lac Fortin and Lac Bouffard and south to Lake Sainte-Anne, a reservoir. From there it flows southwest past Lac Fléché and south into the Réservoir Manic 2, which is also fed by the Manicouagan River. A hydroelectric project on the river below Lake Sainte-Anne began in 2001. The Toulnustouc generating station (capacity of 526 MW) has been operational since 2005. ==Exploitation==