and about 45% of the waterflow of the Caniapiscau now flows through the Caniapiscau Reservoir and on into the LaForge and La Grande Rivers to the west. The catchment area of the Caniapiscau Reservoir is about 36800 km2.

The Koksoak river has an estimated mean discharge of approximately 55 km³ of water per year - though the absence of long streamgauging records means accurate data are not available. Most of the flow occurs during the