@hotspurdotus - You use what space you have available. My ex-wife would never have let me build something this big, but my current wife is really big on aquariums, so she enjoys the pond too. This takes up a fair amount of space in my back yard, but to me its totally worth the loss in ground-space.
Well, I didn't go get rocks today. Decided I really needed an easy day, so I shoveled dirt and built up the banks around the new parts. I trimmed back a good portion of the liner, but in one area, I'm playing with the idea of an actual (small) bog. I decided to leave a shelf and see what I think of the layout. The water is only about an inch deep, but I was thinking there are some plants that really only want that very small amount of water around their roots. However, if I decide I want to keep the area, I think I'll pull back the liner and shovel out a little more depth... which is a shame, because I spent a lot of time filling IN the dirt to build up that area.
Since I have the banks built up a bit now, and the water isn't right at ground level anymore, I'm much less worried about jumpers now. My wife built a crabitat this week, so we're heading to petsmart tomorrow for crabs, and I plan on looking over their shubunkins, and picking up a new batch of rosy-red minnows to throw in. I'm also going to be ordering a batch of plants for the head of the river, and start checking to see who has the best prices on hyacinths this year (although it's still too cold for them).
