Building Liner Ponds
Pond liners can also be used to make an in the ground pond.
Surprisingly enough, it is usually in mid-summer that many
gardeners begin to think about installing a small pond or
water garden. Ponds don't need to be weeded or watered, and
they can supply exuberant color in the form of water lilies
and bog plants.
The sound of a splashing fountain or waterfall is more
appealing than weeding a flower bed or mowing that section of
lawn. Best of all, no matter how hot or wet it gets, the pond
just keeps on blooming!
At this point you may start to think about the expense and
labor of installing a concrete pond, and our 95 degree days
are just about enough to stop this pond daydream in its
However, with the advent of newer pond liners and pre-formed
pools, the misery associated with concrete mixing and
finishing is a thing of the past. Heavy duty pool liners with
10 year guarantees are now common, and can sell for as little
as $1.00 a square foot.
Preformed ponds in many different shapes and sizes are also an
alternative method to create a quick pond at less cost than
using concrete. Using these materials, the average gardener
can install a decent size pond in less than one day, and have
it stocked with plants, fish and fountain by the following
The simplest kind of pond to build is an above-the-ground
pond. Since no digging is required, it usually takes much
longer to fill this pond with water than it does to build it!
There are many variations on this theme, but as an example,
one can use treated lumber planks which are at least 2 inches
thick by 12 inches wide, nail them together to form a
rectangular shape of the desired dimensions, and place the
form where the pond is desired.
This bottomless "box" can be placed directly on the grass,
concrete, a deck, etc., and then the bottom is covered with
some kind of padding or cushioning material. Most books say to
use sand, but I think the perfect material is roofing felt. It
is cheap, convenient, lies flat, makes a barrier to weeds, and
provides a good cushion for the pool liner.
Once the roofing felt is in place, the pool liner can be
dropped into the form and you begin filling the pond with
water. A few staples on the outside of the pond form may be
needed to keep the liner from blowing into the pond, but be
sure to use just a few, and place them at the edge of the
As the pond fills, the weight of the water will do a good job
in smoothing out wrinkles, but if you are a perfectionist, you
can help smooth them out by hand before there is more than one
inch of water in the bottom of the pond. While the pond is
beginning to fill, you can check the level of the form, and if
it needs to be raised a little on one or two sides, this can
be done by carefully inserting some shims to raise the forms
If you prefer the pond to overflow on a certain side (like,
into the flower bed, rather than onto the deck!) then you may
want to leave the overflow side a quarter inch lower than the
rest of the pond.
You should wait until the pond is completely filled before
cutting any excess liner or doing any permanent stapling. This
will give the water pressure enough time to pull the liner
into every nook and cranny where it needs to go; some of those
few holding staples which you used to hold the liner in place
may actually tear loose as the pond fills, but if you stapled
the liner on the outside of the form, near the edges, then no
harm is done... you will be trimming some of that excess liner
It really does take longer to fill this kind of pond than it
does to build it. I once built a twenty-by-thirty foot pond in
two hours but it took all night for it to fill with water.
I think an ideal depth for an above ground pond is about 14
inches, but it can be deeper or more shallow than that,
depending on what materials you are using for the form.
Railroad ties, landscape timbers, concrete blocks, etc. are
all possible materials for pond building.
Remember that any kind of wood must be pressure treated if you
want it to last more than a year! Although I mentioned
rectangular shape, if you have some carpentry skills, you can
also do triangles, pentagons, ponds within ponds, etc.
Ponds built with treated lumber planks do not need any side
support if they are less than 8 feet or 10 feet long; if you
are building larger than that, you will want to drive a stake
into the ground where the planks are to be nailed together, so
the water pressure won't make the planks bow outward. So, if
you know how to use twelve nails to nail four planks together,
then you can build a pond. If you are feeling lazy, have the
lumber yard cut the planks to size you need. Borrow your
neighbor's staple gun, find those scissors buried in the
kitchen drawer, and you are in business!
The advantage is that you can make any shape pond you want,
and the ground itself supports the sides of the liner.
It is a good idea to use a flexible garden hose to lay out the
pool shape you want. Once everyone agrees that it is a
pleasant shape, and it is large enough, you can dig a trench
along side the hose, and start digging.
Remember, the pool does not have to be more than 12 to 16
inches deep, so don't get carried away. If you want a
waterfall, some of the excavated soil can be mounded up near
the pond for later waterfall construction. In some cases, it
may be useful to use some of the soil for a berm around the
pond, so that is another way to dispose of excavated soil.
Once the pond is excavated, check the level, decide which side
you want excess rainfall to flow from, and then you are ready
to line the hole with roofing felt, running it across the
pond, up the sides onto the edges of the pond. Drop the liner
in, weigh it down lightly with some rocks around the edges,
and start filling.
Again, do not trim any excess liner until the pond is
completely filled. Some pond books say you should create a
shallow shelf in the pond before putting in the liner, but
they don't have our river sand and rainfall to deal with. I
think it is better to build the pond to a depth of 14-16
inches, and just use bricks to prop up those bog plants that
don't want to sit too deep in water. This gives greater
flexibility in rearranging the pond plants as you wish, and
avoids the calamity of a shelf suddenly slumping into the
pool. When using pool liners, whether in the ground or above
the ground, it is important to conceal the edges from
sunlight, since that is what eventually breaks down most
Using stones or lumber planks to finish off the edge of your
pond will make it more appealing, and enable the liner to live
up to its ten year guarantee. Even the heavier, preformed
plastic ponds should have their edges covered by sod or some
paving material, so the sun can't reach it. Some final
pointers: if possible, locate your pond away from trees, in a
place that gets at least five hours of direct sun daily. This
will allow you to grow a wide variety of pond plants.
Be sure to use a dechlorinating product when you first fill
the ponds... the new chemicals in our drinking water do not
dissipate quickly and they will kill your fish and damage your
plants, even ten days after you have filled the pond!
Be sure you are pleased with the size and shape of your pond
before you start - so you won't say "I should have made it
bigger, or longer, or rounder, etc.", within two hours of
Rule number one in pond building is that no matter how big
your pond is, you always want a bigger one.
Last, but not least, if you decide to do an in-the-ground
pond, why not serve refreshments and get some friends to help
. . . friends will have all kinds of useful ideas on how you
should do it ... which is fine, as long as they keep
Brett Fogle is the owner of MacArthur Water Gardens and several
pond-related websites including macarthurwatergardens.com and
pond-filters-online.com. He also publishes a free monthly
newsletter called PondStuff! with a reader circulation of over
6,000 pond owners. To sign up for the free newsletter and
receive a complimentary 'New Pond Owners Guide' for joining,
just visit <a href="http://www.macarthurwatergardens.com">
MacArthur Water Gardens</a>
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