GardenBanter.co.uk - Starting a new pond

On 30 Jul, 12:43, TahoeKid wrote:
I'm building a new pond / stream on a slope-to-level surface. The rise
is about 3 feet. All of this will sit behind a newly constructed
retaining wall. The area for this is pretty much pure sand, so
shifting soil is a problem.
Just wondering if anyone has done this and what problems I might
expect to come up against.

Ponds and streams with lners are made every day in areas like lower
alabama and florida in plain old loose shifty sand without any
problems. Once its filled its pretty much there......I know of folks
that made their hole in the ground roughly shaped to size and shape,
mixed in bentonite (bought $7 a 100# bag, and dampen the sand. The
bentonite makes the sand more moldable and sticks it together, then
finish out shaping their pond and line it with liner and fill it.No
big deal..........The water will help the piond hold its shape. No
matter what kind of soil you have its all subject to shifting.

I take it yuor going to use a liner, and your not talking a mud pond.
Even so, mixing in the proper amount of bentonite (western "sodium"
bentonite" ) with pure sand is more than capable of creating a water
tight hole inthe ground that will work just fine for a pond.......At
least with sandy soils, you have good drainage so you do not get a
buildup of hydronic pressure behind retaining walls and liners etc.
Just make sure your pond with a liner is filled before a major rain so
pressure is equalized from inside the liner to the outside. If liner
is in pond and not filled water intrusion into the hole will cause
liner to fold in and poind walls to erode or wash out. Sandy soils
certainly is not a problem.