Ponds or dams? Keyline necessity?

Hi,

I am feeling a bit confused about dams and ponds. Specifically, I want to know whether keyline construction is necessary in any pond construction. In other words, don't people ever simply dig a hole in the ground and seal it up?

We live on a sloped terrain, about 12% or so. We are going to terrace it, and I was hoping to dig ponds into the terraces. They would be fairly small - about 10 or 15 x30 feet or less. Is it necessary in this case to build a keyline, or can I simply dig a hole into the terrace once it is built? I intend on creating inlets and overflows at either end of the pond.

Thanks for the help!

I personally have dug holes and just sealed them up.

As far as I can tell, use of keyline systems just makes it "better" by maximizing water collection, preventing run off,etc.

Even my "holes" were dug on slopes and the dirt removed placed so to direct more water into the pond.

A keyway uses less clay for a large pond. Simple economics.

Aha, I see. So for the size of pond I am looking at, a keyway would be unnecessary, I guess. But one would definitely be necessary were I to build a dam (ie build a wall up from the ground rather than dig a hole into the ground).

What is the maximum slope of the pond walls in my case? I figured 1:1, but maybe it should be 1.5:1 given that we will have to seal the pond with clay coming in from elsewhere (we are on silty sand with a huge variety of rock sizes).

Last thing: does anybody know whether Sepp built keylines for all the dams he made on the Krameterhof?


Thanks for the speedy replies!

generally you want to keep your pond banks at 3:1. this is for safety, so that animals dont get stuck in the pond and drown, and for the stability of the banks so that they dont sluff. you can go a little steeper, but definitely it is not reccomended to go steeper than 2:1. check out the forums at forums.pondboss.com for tons of pro advice on technical aspects of pond contruction. good luck!

I am having trouble with my home made pond.

Lots of bricks and junk has been discovered under my soil.
I wonder if I could jump in on this thread and ask if lining a pond over bricks would be a good idea/ if so what with, thanks. I can only get 2 foot down.

Wow, great Adam, thanks. Looks like a good resource.

I guess we're going to have a pretty shallow pond, in the end! No fish for us.