User avatar
applestar
Mod
Posts: 30514
Joined: Thu May 01, 2008 7:21 pm
Location: Zone 6, NJ (3/M)4/E ~ 10/M(11/B)

Natural Clay-bottom Pond -- an experiment

I dug a tiny little pond last fall. The idea was to create a place to move the goldfish and minnows from the 2 tiny rice paddies to a depth that they can survive the winter. It's not much more than a hole in the ground.

I knew that with my practically solid clay under the turf, the ground holds water fairly well. Carolina Rice paddy only needs to be replenished for evaporation rice growth.

When I dug the pond, I found out that the area in question had better soil than the CR paddy area, and there were good clay loam soil for the first foot or so before it all turned clay. "Uh, oh" I thought. But I went ahead with it anyway. I coated the loamy sides with the buckets of clay I dug up when digging the CR paddy.

Here's a photo before it was all filled:
[img]https://i290.photobucket.com/albums/ll272/applesbucket/Image5702_2.jpg[/img]

But it turned out that my little pond wasn't holding water well. Then with some experimentation, I realized that the water level can be maintained if I left a mere trickle of water running into the pond from the water hose... and I thought I could live with that. We enjoyed the little pond all through the fall, and had 1/2 dozen gold fish in it. I overcame the frosts and little freezes by constantly running an air pump and by disconnecting the waterfall and constantly agitating pond surface with the pumped water.

Then the freezing weather arrived and I realized the "hole" in my plan. There were, in fact 2 holes: One was that there was no way I could leave the hose on a trickle (DUH! obviously) and the other was a phenomenon I didn't count on. When the ground froze, the water started to disappear and the pump tubing became exposed.

The pond maintained itself from natural rainfall for a while, but with the arrival of hard freeze in November, the water level steadily declined. Something about the ground freezing SUCKED the water right out of the pond. I had to give up and wait for arrival of spring to re-design my pond....

WELL! SPRING IS HERE!!! :()

Re-design plans:
‣ HG's recommendation for Sodium Bentonite in [url=https://www.helpfulgardener.com/forum/viewtopic.php?p=117703#117703]this thread[/url] has prompted renewed interest and cast a ray of hope for my pond.
- Position the overflow from the closest rain barrel to divert directly to the pond.
‣ Re-dig the perimeter to enlarge the overall pond surface area and reduce the slope of the sides so the clay doesn't get washed down.

:() Wish me luck! Any comments? advice? :()

a0c8c
Greener Thumb
Posts: 706
Joined: Mon Jun 22, 2009 3:00 pm
Location: Austin, TX

It's been my experience, and my understanding of tanks around here, is that you need a deep hole in order for it not to need plastic. My dad only made his around 4' deep and he needs a liner to keep water in.

User avatar
rainbowgardener
Super Green Thumb
Posts: 25279
Joined: Sun Feb 15, 2009 6:04 pm
Location: TN/GA 7b

I don't know for sure a0c8c, but there in TX your soil may be a lot sandier than Applestars.

AS, I know in my yard, the soil tends to be clay-ey any place it hasn't been gardened, but there are some spots that are more pure clay than others, where I can hardly get a trowel in it. If yours is like that, maybe dig up some of the pure clay to line the pond with?

PS I take it all back, a0c8c, just came across this post of yours in a different thread:

....Under bushes is where I find the best soil, although ours still isn't that much better(with Texas clay I'm sure I could make bricks)

so I guess it isn't that, sorry for assuming! :?

a0c8c
Greener Thumb
Posts: 706
Joined: Mon Jun 22, 2009 3:00 pm
Location: Austin, TX

It all depends on where I dig as well, half of the front yard is 2'' of soil on top, 2'' of sand, and then pure clay below. I think there used to be a driveway there at one point though. The back yard barely holds grass, and thats only cause theres just enough topsoil above the clay below. Only under bushes is there any decent soil. I can dig a 1' hole and water will hold for a while, but it'll still soak in. If I dig a real deep hole I can get it to stay for a couple days, but the earth sucks it up like a sponge sooner or later.



Return to “Water Gardening”