BUILDING A LINER
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
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 morning.
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
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
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
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 where needed.
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 off, anyway.
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
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 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
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
Pond liners can also be used to make an in the ground
pond. 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
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
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