Building a pond is a big undertaking that involves a fair amount of hard
work and, as it will be a permanent feature of your garden, it is worthwhile
spending some time in the planning stage.
So before you rush into the garden with a shovel, pause for a while and
think about your fish pond design and the type of pond that you want ...
Natural Pond - follows the curves and forms of nature and may include an
outcrop of stone or a natural beach. This will often allow planting at the
edge of the pool and can create the impression that the pond was there long
before the rest of the garden or the house were constructed.
Formal Pond - a geometric design works best when there is a relationship
in design and materials with the buidings that are close by. It will usually be
symmetrical in design and could be rectangular or square in shape and may
have a paved edge. Formal ponds are often planted but usually with artfully
chosen plants rather than the wilder plantings of a natural pond.
Raised Pond - a formal pond can also be construced above ground from
bricks, blocks or stone. There will be less waste to carry from the site,
however the cost of the construction materials will be higher than an
in-ground pond.
Once you've decided on the type of pond spend some time working out
possible locations and mark out the locations with a garden hose or a length
or rope. Take into consideration the amount of light in different locations. If
you want to grown water lilies you will require four to six hours of direct
sunlight on the pond during the day. Shade is fine for fish-only ponds.
Check the overhanging trees as these could also be a source of pond
pollution. If you must build a pond beneath a tree at least try to avoid
deciduous trees - the leaves will create a lot of pond waste.
When deciding on the location of your pond avoid the temptation to locate
the pond in the lowest point in the garden. The low point can be subject to
flooding in heavy rain and will often collect runoff from the garden. This may
carry fertilizers and organic debris into the pond.
A pond for goldfish or aquatic plants need only be around two feet deep
although more depth may be required in very cold areas to prevent the
pond freezing in winter. If you want to keep koi in your pond it will need to
be at least three feet deep or more.
The biggest mistake that water gardeners tend to make is to build a pond
that is too small. Your finished pond will appear much smaller than your
original layout!
If your pond is to be dug out rather than raised consider how you will
remove the excavated material. It may be possible to use it in another part
of the garden, alternatively you may need to have it removed which can be
difficult and expensive.
Assuming you are going to build a sunken pond the next step is to start
digging! Dig the pond to the desired shape and dig a shelf around the
perimeter of the pond about one foot deep and one or more feet wide. Dig
the remainder of the pond. If you are planning a waterfall dig the pond with
a slight slope away from the waterfall.
Line the excavated pond with underlay. This is to stop the flexible liner from
being pierced by sharp stones. Pond underlay can be made from geotextile
or old carpet, providing it is non-organic and non-rotting can be used to
save money. A butyl rubber pond liner is laid on top of the underlay.
Position to liner evenly in the pond and try to minimize the folds and
wrinkles. Leave an overhang of at least six inches. Avoid walking on the
newly laid liner as much as possible. If you must walk on it wear socks!
Fill the pond and try to ease the wrinkles out of the liner while the pond is
filling. Arrange coping stones around the edge of the pond and fold the liner
up behind the stones ensuring the edge of the liner is above the water level.
A more natural edge can be created by planting shallow-water plants
around the edge of the pond. You may need to consider cementing the
coping stones in place if the pond edge will be subjected to much foot
traffic.
Now sit back and enjoy your new garden pond!
