Thanks for all the advice. I attached a picture of the pond for reference. The last 2 are pictures of the end of the dam where the water has been flowing over. Not very much does and it only happens when it rains very hard. It has made that part of the dam very thin. He plans to build it up and make it where I can mow right up to it.

My siphon didn't work very well so I started using the 3in trash pump. I will probably install a siphon style overflow. What do you think the best way to seal around the pipe will be. Will clay be enough or will I need anti seep gaurds.

-- I tried to attach the photos but it says the limit is 2MB per file. The pictures are all over 10MB a piece. What is the best way to attach them?