No, there is no such thing as too many ponds. There are no rules in nature, this is all site, landscape, and climate specific. You must watch your property, read the book of nature, and learn from what observation tells you. The earth is in a critical state of dehydration and desertification because of the human impacts on the landscape. We very desperately need to start reversing this. Nature provides
enough water everywhere, yet 1 billion people do not have sufficient access to clean drinking water. With the world in it's current state, you can't have too much water. Water space is highly site specific, but as a general rule of thumb it is good to have at least 10% of the whole area as water.
Judith, Johnny, Zach and Team Holzer AgroEcology