For any site, a classic permaculture design footprint is the carpet sandwich pond. The technique uses sections of discarded carpet — nails removed — as protective padding to enclose either plastic or EPDM (inner tube material).
The basics are: dig your pond shape; lay a carpet down, knap side up; lay in an appropriately sized piece of several mill plastic sheeting, or EPDM (as a liner), place the second carpet (knap side down) over the liner.
The liner needs to be large enough to fold back over the edge of the top carpet (otherwise, your water will wick out). This “fold” can be hidden by stones placed on the edge, allowing a much more natural pond design.
With the addition of water (from roof, well, runoff, or spigot) One’s pond is almost ready to function in the landscape. (Tap water needs to off gas chlorine for a day or two). Inoculate with a small amount of water from a healthy pond, add some plants, and very soon your pond is up and running.
Barefoot Permaculture’s 8’ bean-shaped pond was dug as part of a hands-on class for a Permaculture Design Course (PDC) several years past.
One of our reasons for the pond is to restore amphibians to our high and dry landscape, by providing a wetland for mating, egg-laying, and tadpole/pollywog habitat.
Every spring, during my travels, I am on the active lookout for tadpoles. With my truck, I am never without: dip net, 1 gallon and 5 gallon lidded, plastic buckets, rubber bootlets, and for use on longer travels, a plug-in power transformer as well as a fish tank bubbler (for oxygen).
Having already established functioning populations of Wood Frogs (Rana sylvatica) and Cope’s Gray Tree Frogs (Hyla chrysoscelis), we are selective with what species we now bring in.
We have had some success with Leopard Frogs and American Toads, yet not so for breeding populations.
High on our desired species list are Spring Peepers (Pseudacris crucifer) and more toads (Bufo spp.). We avoid tadpoles of the larger Green Frog (R. clamitans) and Bullfrog (R. catesbeiana) due to their appetite for smaller frogs.
Early on, we learned the hard way that while goldfish are great at mosquito larvae control, a wiggling tadpole provides a more substantial chewing experience.
Goldfish set loose in an 8’ pond, can be extremely difficult to catch, in some cases, taking months of attempts before net meets fish.
Needless to say, goldfish are not welcome.
In early March, a visitor remarked about our goldfish pond. Oh no, we replied, this is a tadpole pond: no goldfish here! She replied “I know a goldfish when I see one, or in this case two”!
Sure enough, 2 goldfish (most likely products of a neighbor child being tired of the responsibility of fish care, and dumping them in our pond).
One I caught immediately: the other hightailed it for protecting vegetation.
One might think that with a small pond, a dip net, and hunter instinct of a large brained Homo sapiens arrayed against a small brained, cold blooded, Wal Mart fish, it would be over soon.
One would be wrong.
I snuck out, net in hand, multiple time daily, as well as several times during the nights. Not only did I not catch it, I hardly ever saw the fish. As spring came on, duckweed covered the surface, and I would harvest as much as possible, in order to create a visibility zone.
Meanwhile, I had little choice other than keep placing in all the special species of tadpoles I was locating. Many hundreds were added: surely some would make it through safely.
A week ago (7 May, 2012) in the midst of orchard and garden work, intuition reminded me of the goldfish. I went over to the pond, and saw a glimmer of fish under the duckweed. A quick dip and HOORAH! The fish was caught.
I placed it in the 20 gallon tub with the other goldfish, noting that during the 3 months feasting on tadpoles, this freshly caught fish was 2 & 1/2 times the size of the other.
Perfect timing! Our Cope’s Gray Treefrogs were just now calling in females to mate and lay their diminutive rafts of tiny eggs…