Building a Liner 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 tracks.
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 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 liner.
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 where
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 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!
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
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
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 liners.
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 filling it!
Rule number one in pond building is that no matter how big your pond is, you always want a bigger
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 digging...
**************************************************************** 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 MacArthur Water Gardens.
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