1) Quality private fishery
2) To enhance land value
6) To attract wildlife for viewing and/or preservation
10) To study aquaculture
11) To study all of nature and/or biology
15) To provide non-powered water sports (ie; canoeing, rowing)
16) To provide escape, peace, and relaxation (therapeutic or otherwise)
20) A family or personal challenge of actually building it
21) A family or personal challenge to maintain a complex ecosystem
24) A fun place to gather with family and friends