In times of flood and unusual water currents, most of the fish you are collecting would prefer to shelter not forage. So I suggest some flat tiles or slate propped up at one end (downstream end). Fish will gladly take refuge from the current and predators by hiding underneath and will be easy to find. Simply lift up the tile and scoop. Dont put these traps too near logs or rocks as fish will choose the biggest safest shelter instead.
You could also try some pipes for this.
You could also try some pipes for this.








