You should consider first what type of pond you want, in this case pond with waterfall feature. Would it be a home for fish and plants, these are things that you should take into consideration as well. But please keep in mind the most common mistake made when constructing a pond is the size, do not make it too small, if you decide to add fish at a later date, it will only make you more work as your pond may not be big enough.
You will enjoy your pond more if you install it close to your home, or window, this way you can watch all the wild life visiting all year round. The pond needs to be located away from any drain pipes, keeping it away from any run off of rain, as this may contain contaminates. Also do not build your pond too near to trees as you will always have to be removing dead leaves and debris. Try to position your pond where it will receive a maximum amount of direct sunlight, this will aid the growth of plant life.
Determine the size and shape of your pond
This can easily be done by using a length of rope or string, or even a garden hose pipe. Lay the rope down where you require to the shape you want, you can then either peg the rope down, or use chalk powder. Now you can start to excavate, digging it to approximate six inch depth, making this the first shelf., this is called the coping shelf, dig down a further twelve inches making this the second shelf, and then a further six inches to the base of the pond. The reason for this shelving is for different types of plant life, and maybe the fish you are going to put into your pond. Remember a larger pond is more stable and easier to keep.
Once you have got your pond excavated and ready, you need to line the hole with soft sand, minimum of half an inch thickness, and pat down firmly. You are now ready to line your pond. You can buy pond liners from any good garden centre or pond specialist. Determining the size of your pond liner is simple, measure the maximum length and width, add the depth twice to these measurements, plus a foot or two for overlap and this will give you the size. Lay the liner into the bottom of the pond and feed it into the contours of the shape, remembering first to remove your shoes before getting into the pond. Once you have completed all the contours pushing the liner into the back of the shelves, keeping folds to a minimum, start to fill your pond.
This is the time to start construction of your waterfall, first we raise the level to make a slope for your waterfall, this can be achieved by either a pre-formed waterfall mould, or you can make it yourself by using stones, or soil remembering to shelve it up to the desired height, cover this with more soft sand then place either your preformed waterfall mould or rubber liner, making sure if you use the liner that you have it pushed well back into all the recesses. Then you can add an external water tank, which will re-circulate the water from the pond down through the water fall, to do this you will need either an electrical pump, or solar pump, you can both from a garden centres or pond specialists. The pump should be placed in the bottom of the pond with a feed pipe running to the waterfall tank, this pipe should be buried in the ground for safety reasons and not be unsightly,
The finishing touches
All around the pond, your first shelf which was called the coping shelf is now ready to have the coping stones put in place, these can either be decorative paving stone, or cobble stones, this holds the liner in place and gives wild life a way of climbing in and out of your pond. It does not harm adding a few stones onto the other shelves of your pond. This is also the time to add your plants such as water lilies, oxygenated plants and other decorative water plants that add colour to your pond throughout the year. Now you should link your pump to the power supply, switch on, and then you will see the water level go down, now add more water to just below the coping stones and then you have your final result.
Your pond will be a really nice relaxing feature in your garden, to watch and listen to on warm summer evenings.