I am building a large pond comprising three separate pools and two waterfalls. The waterfalls comprise a brick wall, with the top row of bricks removed, so that water flows over the area with absent bricks:
_________ _________ _________ | | | | | |_________|_~~~~~~~~~~~~~~~~~~~~~~~~~~~_|_________|_________| | | \\\\\\\\\\\\\\\\\\\\\\\\\\\| | | |____|_________|_________|_________|_________|_________|____| | | | | | | | |_________|_________|_________|_________|_________|_________| | | | | | | | | |____|_________|_________|_________|_________|_________|____|
During testing, small fish about .5" long flew over the waterfall, even though the waterfall had only a thin layer of water there. Since larger fish will be kept in the other pools, it is important they don't get swept over. I've considered placing a fine net across the top of the span where the missing bricks are, to stop fish from going over, but I suspect the small fish will still get trapped by the current and stuck in the net. There must be some technology, perhaps developed for the fish farming industry or for dams to prevent this problem.
Is there any way to modify the construction in a way that prevents the baby fish from being swept over or trapped by the heavy current absent of turning down the pumps?