wildlife pond edging?

I think I will leave all of the edges under dirt and will plant some
marginals along the edges in the dirt. I don't know alot about
setting up a bog, but I think I will look into putting a bog along the
side of the pond for a natural look. How much water will be "wicked"
away? Will I need to replace more water? I only need to replace water
in my other pond when we have very windy days, or if it does not rain
for a long time. If i put enough dirt into the edge of the pond maybe
that would allow for more flucuations in the water level.

Tracey