There is nothing quite like having moving water in the garden and while many pond-owners opt for fountains or waterfalls, ornamental canals offer an interesting and somewhat under-used alternative way to achieve it. Particularly at home in formal settings, a canal is an ideal way to link geometric ponds, or provide an extra focus point to statues or groupings of sculptures. The strong lines and vertical edges required to make the canal look its best mean that concrete is usually the material of choice, but fortunately building one is not a particularly difficult job, provided one or two points are borne in mind.
Planning Your Canal
One of the key points to get right is to make sure that the canal is in keeping with the rest of the garden and pond design; if it is not the whole thing will jar and far from adding to the overall look, it could ruin it. Matching the scale and feel of the proposed new construction is essential, since it needs to complement the existing water features, not dominate them. If anything, it is better to plan to make your canal a little on the narrow side, rather than risk building something too wide which would look out of place; a well-made water channel only around 10 or 12 inches (25 or 30cm) wide is quite big enough for most gardens.
The route of the canal obviously needs to be planned too – although the positioning of existing ponds or any other features may play a large part in dictating where it goes. It is important at this stage to consider whether you may need to accommodate water pipes or electrical cables either for this construction, or for any future project you might be contemplating. If so, remember to plan for whatever conduits or trunking you need – and decide where they will be positioned.
Getting Started on Your Canal
The shape of the canal needs to be marked out on the ground – using a series of pegs hammered into the ground to hold rope or gardener’s twine is one of the simplest ways to do this. After making sure that the lines are true, you can start the excavation, digging down to about 8 inches (20cm), taking care to ensure that the edges are level and that there is a gentle slope to carry the water along. A 2 inch (5cm) layer of sand should be laid in the trench you have created and then firmed down to make a good base, before the whole canal is lined with heavy duty polythene sheeting and concrete poured on top. The concrete should be tamped firmly along the length of the channel with a flat piece of wood to make it smooth and then left for a couple of days to thoroughly harden.
The next step is to create the walls of the canal, which is usually done by building a low wall up from the base – normally a course or two of bricks, topped off with a suitable tile layer which over-hangs the inside edge, ultimately projecting over the water’s surface. When the mortar has completely dried, the whole of the inside needs to be skimmed with a half-inch (12mm) coat of fibre-reinforced cement and then again left to harden properly. Once it has dried, it should be painted with a suitable brand of water sealant, which will prevent the lime in the cement from being leached out into the water.
Although building an ornamental canal is a not a quick job, if you take the time to plan it out properly, check and re-check the levels and take care over your concreting and brick-laying it needn’t be a particularly daunting one. Then all that remains is to connect the pump and attach the appropriate hose pipes – and enjoy the sight and sound of moving water in an rather unusual type of garden feature you built yourself.