Brettski: Do you think I should copy/paste my posts in a new thread? I didn't mean to hijack your thread.
burger: In this part of Georgia there are normally no really dry periods. The average annual rainfall is almost 60 inches. If we get back to the regular weather pattern the pond level will stay relatively high, keeping the shallows flooded all year (with a properly constructed pond of course!). In that case I wouldn't get the variation in level that you describe. In fact, I'm a little concerned because I believe that normally the little branch that feeds the pond runs constantly. I haven't been here for a full year yet, but I was here to visit a few times before the drought and I think it was always moving.
So far I don't see either willows or chinese tallow. I'm thinking that if I could lower the pond level to expose the shallow area for several months at a time I could easily go in and clear out any undesirable trees. The sweetgums are already very common in the pond site with a few individuals that have 18 inch diameter trunks. The Water oaks are just as big and plentiful.
I'm curious what would happen if the pond was at the highest level and shoreline weeds became too thick. Could I lower the level and dry them out? On the other hand if the pond had been at the low level for several months with a similar weed problem, what would happen if the water level was increased by 2 or 3 feet?
Would it be practical to use two siphon spillways to create the two different levels? Could you just install a valve on the lower siphon and simply close it to raise to the higher level? I think I've read about people here using two siphons on one pond. Would that be typical on a pond this size? Would both siphons function properly if one was 2 feet lower than the other? I guess the higher siphon would have to be larger in case the lower siphon was closed and it had to handle the entire overflow.
