Ponds and lakes can add value to your real estate.  This will value will certainly increase moving forward as a recent change in the Clean Water Act gives the Corp. of Engineers jurisdiction over all perennial streams in the US not just navigable water.  A perennial stream or perennial river is a stream or river (channel) that has continuous flow in parts of its stream bed all year round during years of normal rainfall.  This means that before you build a pond or lake on a perennial stream you must get Corp. approval unless you can qualify for an agricultural exemption.

Here are some things to consider IF you are able to build a pond or lake on you property.