Well be just got an inch of rain and the pond siphon is working but I also have water going down the emergency spillway. I'm thinking by the time the water is over the 10" pipe to start siphoning I am already at emergency spillway elevation or close to it. I just dont have the added capacity to allow time for the siphon to keep up. I think the answer is to add 2 or three feet to the dam brest.
Sounds like it. Are you absolutely sure that the vent is at least as low as the top of the crossover pipe? If so, the crossover pipe was set at to high of grade. That hurts
