Hey Joe,
Bruce always has some great ideas. If you do plan on using the pond for some type of swimming, I would not suggest any electricity in the water either.
Yes, a shore-mounted pump can be used with a draft tube placed at the bottom of the pond. I would make sure you have some sort of screen to help reduce the large debris from damaging your pump. Also, by using a float or duck decoy attached to this draft tube, you can lift it out to clean it. That is if you use flexible PVC pipe.
The suggested flow rate for a water fall to provide a good looking display is 1500 gph/foot of width of the waterfall. As for evaporation, we install garden ponds all around our area here in the mountains of NC and we find evaporation to be a small factor. Actually, the splash out created by the water bouncing off the rocks causes more water loss than any other.
Using this method will circulate the pond, at a much slower rate than conventional aeration. Keep in mind the rate will be dependent on 1) the size of the pipe, 2) the rate of the pump in gph 3) the rate that the cattails or what other macrophytes you have in the upper pond remove the unwanted gases and nutrients.
Your electricty cost, construction cost and overall maintenance will be much higher than a conventional aeration diffuser placed at the bottom of your pond too.
These are just some things to put on your pros and cons sheet when planning your pond. Keep us posted on your progress.
