The flow has to be sufficient to keep the eggs suspended in the water column. I seem to remember that they need to drift at least 72 hours at a minimum. When the water is a little cooler than optimum then they would need a longer drift. Supposedly stripers used to spawn in the Merrimack before there were dams. Also there are rivers in North Carolina and Florida where they reproduce. And of course the West coast has a few, such as the delta area around San Francisco. **David**