very interesting Penoke, thanks - your picture with the downstream rock dam actually looks a lot like my situation, though you have more water volume ...
... I found a local env eng. who worked for a neighbor and who is going to come out and take a look ... more to come ...
Depending on where you are, that island may or may not help. My wife had some ducks on the family pond when she was little. Coyotes, dogs, etc, would chase them into the pond, where they would happily take refuge. Then it got cold outside, then the pond froze, then the coyotes chased the ducks into the pond. Then they walked out after them and ate them.
</font><font color="blue" class="small">( That must be where the old "fly south for the winter and not be somebodys dinner" came from /forums/images/graemlins/wink.gif )</font>
No, no that doesn't work either. We wait for them to fly down here every winter. Duck and goose really add to the flavor of a gumbo!
I am liking that island idea though, as I will need some ducks to control duckweed. We have plenty of coyotes around here and a few criminal dogs.
The pond I have in mind is really too small to handle ducks (not that they won't invite themselves in), and too close to the house - I wouldn't want their waste by the front door ... I do want fish and need to find out if it is okay to have Koi in a pond that is directly part of a stream (because their spawn would infect the river) - the Eco guy is supposed to come by next week, so I'll know soon enough ...