alternative to plastic pond liner?

[laurarice]

Traditionally ponds on the mainland were constructed to be naturally sealed with a clay bottom. I am looking for info on whether this has been done in areas of the big island that have clay soil such as parts of mountain view. i realize in most cases people use a liner, but has anyone NOT used a liner? What technique for making the bottom water-impermeable worked?

Laura

[HereOnThePrimalEdge]

I knew two people who lined a lava puka in their yards with concrete to make a modest sized swimming pool. Neither pool was too deep so didn't need to carry a lot of weight, and there were no trees nearby with roots seeking out water that could create cracks.

No fathers or mothers think their own children ugly; and this self-deceit is yet stronger with respect to the offspring of the mind. -Miguel de Cervantes, novelist (1547-1616)

[Malapuaao]

I heard of a certain kind of grass up in the wet zone of Glenwood that is used to make shallow ponds but realistically concrete or gunite is too expensive by comparison to pond liner and we do get earthquakes that would require concrete to be not insubstantial engineering or you'd be throwing your money away anyway.

aloha

[Lee M-S]

There was a natural pond on our property in the Acres when we moved here. We cleaned it up, added plants and tilapia. A couple of years later, I came out to find the pond empty of water, and the fish flopping in the mud. Whatever sealed the cracks shifted for some reason; I suspect it might have been lotus plants that rooted in the bottom of the pond.

We got some bentonite (the clay used to seal ponds), but apparently not enough; the pond stays empty.

For another spot, we lined a natural hole with chickenwire and cement (or maybe concrete, I can never remember which is which); the water seeped through the uncracked coating, and the pond emptied quickly. We lined the concrete pond with 6ml plastic from Home Depot; that has lasted 4-5 years so far. I read about a liquid coating you can apply to seal concrete, but it was expensive. Someone told us that a layer of the plastic under the concrete would have worked. Let me know if you try that...

A friend just above Mt. View, on the North side of the highway has a natural pond that doesn't leak (or at least, hasn't leaked so far). She mentioned that she has clay soil.

If your pond is small, you might ask a pond builder about scrap liner.

Come to the Big Island Water Garden Club--great place for all kinds of pond info. Meetings are the 3rd Tuesday every month, 7pm at the Keaau Senior Center behind the police station. Usually, there's a speaker, potluck pupus, plant auction, and free plants. Often, there's time to ask questions of the group.
Newcomers are welcome, members are friendly. Come for free, join if you like; I think it's $10/year membership.
At least 2 pond builders and one fish seller are regular members.

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[terracore]

Four years ago I used a cheap blue poly tarp (it wasn't even new) thinking it would hold up for a few weeks so our ducks would have a place to bathe and swim around in circles. Four years later its still there holding in the water, having held up to the ducks, geese, and even a big dog. Somehow it attracted bull frogs, dragon flies (including larvae), even african snails go there to drown. Every day I see water is still in there I'm surprised. There isn't even anything cushioning the plastic from the sharp lava rocks. Usually people put old carpet or something under a liner.