just my 2 cent opinion. As they say demand and supply. All things being equal the pond property will comand a higher price. I just bought my pond property and I looked at other comps without a pond that were less. I may represent a new part of the market.
1. the pond is on our seasonal residence
2. we have owned lakefront property and tired of the higher taxes and noise from the lake (motor craft etc)
3. we are near retirement age.

As lake frontage property is becoming more scarce and demand for water type property increases the babyboomers should help drive up the cost of a good pond property.