Building a garden pond using a flexible liner is generally straightforward but there are some pitfalls which can be avoided in the light of experience. Many of these are not mentioned in the literature so it is worth taking a few minutes perusing this page of hints. At the risk of repeating myself here are the main stages in constructing a garden pond:
1. The ground must be level, if it is not you will have great difficulty in disguising the liner, unless you can get some sloping water.
2. Make the hole as large as you can to fit in with your design. The most common co-plaint on completion is ‘I wish I’d made it bigger’.
3. Mark the perimeter of the garden pond i.e. where the water will end, using sand. Many books suggest a hosepipe or rope but this does not work in practice.
4. Before you dig think. Where is the soil going to go? Don’t be sucked into using it for a rockery unless that’s what you really want. Sometimes, if the soil is of good quality, some of it may be used to raise flowerbeds in keeping with a design. Otherwise dispose of it in batches rather than working round it and plan to handle it as few times as possible.
5. The contours should have been decided in the design process but usually ponds have shelves dug into some of perimeter for plant containers (backward sloping so pots don’t slide into pond), a gently sloping bank to allow wildlife to enter and leave, and a variety of depths (1 to 3 or 4 feet). If, say, a pebble beach or other feature is to be included the effect on the depth must be considered.
6. After excavation remove any sharp stones or other objects which could damage the liner. Be particularly careful with roots and remember they may continue to grow after installation with disastrous effects.
7. Line the pond meticulously. We use sand and old carpets for this, although purpose produced underlay is available. Leave nothing to chance when it comes to leaks. It is heartbreaking to put all the effort into construction only to discover a leak a few days later. Again take great care with lining.
8. Installing the liner is fairly straightforward process. If the liner has a shiny side and a dull side lay it shiny side down. This will make it easier to install and reduce reflections in the completed pond. Position the liner centrally over the hole, lightly weight down the edges and start to fill.
9. As the pond is filling smooth the liner and try to fold it in such a way that there are fewer large folds which will lay flat. Some rearrangements may be needed here but it is well worth the effort to get a more professional effect.
10. Fill to the top and use the water level to check how level the edges are. It may be necessary to make some minor adjustments here but be careful with the spade!
11. Allow to stand for a day or two before proceeding with the next step which is edging.