A very simple, fast, inexpensive and effective way to construct a waterproof water feature is by the use of a standard precast concrete drainage section of the type used in the building of manholes. The concrete rings vary in size and length, and usually have a foot rung built into each section.
This particular pond was shown at the Chelsea Flower Show, where a neat, crisp and tidy pool was required to service a copper water feature (by Humphrey Bowden), with an integral fountain comprising a simple 50 gph submersible pump with copper pipework, requiring a water reservoir.
A base is formed using wet mix 1.6 concrete, 100mm deep x 300mm wider than the diameter of the chosen concrete ring. The precast ring section is set onto and into the wet concrete, ensuring that the top is level. Unless you are using a solar powered pump, you will also need to install a conduit for an electrical cable. This is also set into the wet concrete to ensure a watertight joint. The inbuilt foot rung is useful to secure the conduit, ensuring that the pipe is above the required water level to prevent back syphoning.
To create an illusion of greater depth, the whole of the interior is painted black, which also disguises the conduit and foot rung. The pool is completely watertight, and having very narrow sides/edges, the surrounding area can be planted without detriment to root systems, or the need to allow for foundations/haunching normally associated with concrete pools.
The costs will vary dependent on the ring size, but the materials for this 900mm pool were no more than £60.00 including concrete base. Labour costs – around four hours including digging the hole, construction and painting. Compare this with the normal rates for building a pond, and you will save a great deal of money – and have a 100% waterproof feature!
