I posted the following for someone earlier... the extra dirt can be used for a waterfall or river. You have to put it some where so put it next to the hole you dig for your pond. Use the liner to control the water flow. Place different size stones for the water to flow over. Let your imagination be your guide.
Simply just dig a hole the size and shape you want and put a liner and fill it with water. The best liner I have found is the rubber roofing used on flat roofs. They are available from most roofing suppliers. They are available in ten and 20 feet wide and as long as you want. Important that you get it much larger than the hole and you can cut the extra off. the liner has to go across the hole and down the sides. you can place stones or any thing that meets your taste on the edge to cover the liner. Be sure you leave at least a foot of material on the top edge so the liner does not slide down into the pool. Place rocks or something on this edge to hold it in place.
You can place a pump and filter and fountain and make water falls all in similiar ways. you can plant trees, shrubs, ornamentals and water plants. Many types of fish will do very well. If you are in a hard reeze area you may bring the fish in and winter them inside. This is a whole different subject.
Some home improvement show on TV have shown how to do this and they can be pretty wild and crazy. Let your imagination go!!!