Originally posted by: Pliablemoose
With the added organic material from duck poop, you should consider a large pond.
I was going to say the same thing.... I've got 2 ducks (this week anyhow... the female is currently sitting on 15 fertile eggs), The bottom tends to get kinda mucky from the duck sh!t. Personally, I'd go deeper than 1 foot... probably at least 2 or 2 1/2 feet. Consider a submersible sump pump instead of a specialty pump made for ponds.... the submersible pumps start at about $50; compare the gallons per hour flow for each type and see for yourself how much cheaper they usually are.
For pond plants, you can pick them up dirt cheap on ebay this time of year. Water hyacinths spread quite quickly, are dirt cheap, and have fairly nice flowers. You'll want to keep about 1/2 of the water surface covered with some sort of plant to help control algae.
IMHO, freeform ponds (using a black rubber lining) are a little more satisfying to build. I don't see any need for a concrete liner... simply dig out a hole of any shape you choose. If your soil is fairly compact, you can make the sides nearly vertical. It's best to leave a relatively level ledge about a foot wide and a foot deep around the perimeter of the pond. This is for potted water plants. Then, taper the bottom of it toward one end... this helps when you do the annual pond draining and bailing out of duck sh!t. Line the hole with newspaper (2 or 3 sections thick, more if there are sharp rocks), then carefully spread the liner over the hole. For the liner, you can get it at garden specialty places, or you can get the rubber roofing (not the torch down stuff) from a hardware store... it's pretty much the exact same stuff. Then, start filling the pond with water, occasionally pulling the liner tight to minimize wrinkles. You don't have to worry about the top edge of the pond being perfectly level yet.... Once the water is a few inches from the anticipated top of the pond, it's time to start working around the edge of the pond with small hand garden tools.... either remove dirt or add some dirt until everything look really level... you can fine tune it further when the water is up all the way. Good luck! I've done quite a few ponds already. Only one of them was a preformed plastic liner. Personally, that was work, versus a pleasurable experience in creating something nice in the yard.