I would use the red pipe diagram and extend the pipe further into the pond, close to the bottom, if you can.
That is what we wound up doing, except the contractor talked me into putting the inlet at the bottom of the catch basin, which is below the pond's full-pool level. That means I will need to install an elbow to prevent back-flow from the pond. In the meantime I just stuck a pot into the inlet as a temporary plug to reduce the pond filling while I finished the pier/gazebo. With all the rain we have had this fall, the pond has filled a lot quicker than expected. Today it is about six inches above full pool. This shows the level almost over the top of the overflow pipe.
This morning I took a look at the catch basin, and it is also almost full. That means the pond is about a foot above the catch basin, and water is flowing backwards from the pond to the catch basin. It doesn't show up well in the image, but there is a definite eddy over what is supposed to be the inlet on the right side of the catch basin. I also have not installed the planned flap valve on the outlet of the catch basin; the catch basin is full even without the flap valve, because the drainage ditch is partially obstructed down stream on my neighbor's property.
If the rain ever ends, maybe I can get the elbow installed to eliminate the reverse flow. Although I didn't need the auxiliary filling this year, I'm sure it will help during the dry season of the more normal years.
