In the river systems the females carrying eggs are spawned. But the eggs just sink to the bottom. They need river current to drift. 37 miles of river is needed, more in the rainy season. In a fast moving current, the eggs hatch out at a considerable distance downstream from the spawning place
A flow velocity in the river of approximately one-foot per second is required to keep the eggs afloat. If the egg sinks to the bottom, its chances of hatching are reduced because the sediments reduce oxygen exchange between the egg and the surrounding water. The flow rates of the water are basically controlled by the upstream flows from dams. Egg mortality is high, especially in water temperatures above 70 F, but many eggs are laid to increase survival. Less than one percent of the eggs will survive the fist two months.
Only about a dozen rivers in the U.S. and 2 in Canada support successful spawning.
In a lake without these conditions the chance of survival is near zero. Im not even sure the eggs are released in the lakes. They must be constantly restocked.