Another thought.... You can make ponds by using clay as your "liner". I do
not know how large your pond is going to be (sounds large if it is going to
have the boulders of this sized not overwhelm it..) or how costly this would
be ...
http://www.eman-rese.ca/partners/ado...ck/part27.html
Clay Ponds

If your soil particle size is small (sandy, silty soils) with a clay content
of at least 10% then soil compaction is the easiest way of sealing the
bottom of your pond. Alternatively, soils with a clay content of more than
20% can be imported for compaction. Alternatively, bentonite clay can be
purchased.

Although clay lined ponds are the most natural looking, clay is not the best
choice of impermeable barriers for backyard ponds. The clay itself is very
heavy and can leak if not installed correctly. Bentonite clay is applied at
the rate of 1 to 3 pounds per square foot, tilled in, and then rolled to
compact the particles. Use a sprinkler to wet the bentonite before
compacting. Bentonite swells when wet but if complete drying occurs
bentonite shrinks and may compromise the seal. Add water immediately,
otherwise the clay will dry out and crack. If you empty the pool it must not
be allowed to dry out. A mixture of sand and earth is placed on top to
protect the water-resistant clay liner from mechanical damage.

Geotextile clay liner is a product that sandwiches bentonite clay between
two layers of felt. The felt is sewn so that the clay cannot move and
collect anywhere along the width or length of the roll. Geotextile clay
liners are generally used for large farm ponds, and are expensive.

Consult your bentonite supplier for alternative methods of application
(including adding bags of clay directly to the pond to achieve a water
barrier as the clay particles settle out on the pond bottom).

"John Arruda" wrote in message
news:_aDVa.27391$o54.23709@lakeread05...
It would be very tough since the boulder is almost vertical.
"dkat" wrote in message
.net...
IF you can get a perfect seal of the liner to the boulder then you
should
be
able to have the liner anywhere below the boulder that you can fit it.
The
problem is getting the perfect seal.... I take it you don't have the
equipment to put the boulders in on top of the liner...... DK
"John Arruda" wrote in message
news:mjkVa.26246$o54.10038@lakeread05...
I am currently building a pond (still digging). I have large boulders
that
go 2 ft below water and come 4 ft out of the water. Theyre about 10
ton
or
so.
I would like to have the liner below the water line and glue it or
silicone
it to the large boulders making it waterproof. I really dont want to
show
the liner above the water and stacking stones on the liner and boulder
would
be very difficult since it's almost vertical.
Has anyone come across this dilemma?? I see many pond pictures on the
internet with similar setups but they dont tell how the liner is
hidden.