Create beautiful garden spaces with ponds and water features
For those with space to embrace, building ponds and water features adds magic to the garden, the sound of running water on a warm summer’s day brings quintessential stress relief and tranquility. For those with a creative streak, building them is also great fun too and it’s easier than you may think if you follow our straight forward principles.
Pre-planning and excavation
It is helpful before you start to draw a plan of what you are trying to achieve, measuring the size, depth and the ledges for planting areas. You also need to know the size of the pond liner and the geotextile underlay you will need. You will want a good quality pond liner and they are not cheap.
As a guide, an 8m – 4m pond with a maximum depth of 1.5m will require a pond liner with a minimum size of 12m x 8 and will hold about 50,000 litres of water. In the UK, a liner that size will cost you around £200 and it is always better to get the thickest and highest quality liner rather than trying to economise. Likewise, you will want a high quality geotextile underlay to protect your liner from root and stone punctures.
It is always helpful to get a liner that is slightly bigger than you will need, particularly if you are considering adding a waterfall, so you can calculate the size of the pond and the liner needed for the waterfall at the same time.
If you want fish in your pond, you should consider a deeper solution, larger fish prefer deeper water and in any event you will need to make provision for when the water freezes, we recommend your pond depth being at least 1 metre at the deepest point.
Whilst a small pond can be dug easy enough by hand, by far the easiest way is to bring in a mini excavator. You can hire one for around £60 per day in most places in the UK. You will want the sides of your pond to be between 60 – 70 degree slopes all the way around, rather than vertical 90 degree drops. Large ponds tend to have more gently sloping sides, at 35 – 45 degrees.
Depending on the size of your hole, we recommend a dumpy 1,000KG bag of sand, you can always use what’s left for the concrete needed to construct your waterfall and to secure the large stones needed around your rockery feature and marginal stones. Once you have finished digging, remove all large stones and cut and tree roots back as far away from the hole as possible. Use the sand to infill any areas needed to make the edges of your pond smooth, then you are ready to install the underlay. A good quality geotextile underlay is a worthwhile investment. Lay the underlay in your pond and ensure that you have at least 30cm spare all the way around after you have pushed the underlay to the bottom of the pond and all around the sides.
Water is always level
The shape or size of the pond is immaterial, the most important part is to get the levels right, there’s nothing worse than an exposed pond liner or one side higher than the other, so, make sure the ground is level all the way around your pond site once excavation is complete and you can’t go wrong. The easiest way to do this is to use a plumb line, or to with scaffold boards and a spirit level, checking the level from left to right and front to back.
Are you going to build a waterfall?
Waterfalls are very attractive and make a great way of oxygenating your pond to stop the water from going stagnant. It’s for healthy fish that the water is clean and well oxygenated. You can be creative, as long as you follow some basic common sense principles.
When planning to construct a waterfall, we recommend not filling your pond until the works on your waterfall is complete.
Use the soil excavated from your pond to raise the waterfall by heaping up the soil to the desired height. You may want to make a fairly large water feature by using a lot of soil, it’s a good idea to have a body of water at the top of your waterfall that fills and once it reaches the correct height, spills over either into a small stream then dropping into your pond, or directly over the edge of the waterfall into your pond. You will also need to think about a housing for your pond filter. We like to incorporate this into the waterfall construction by building a housing for your pond filter with a door on it for ease of access so you can clean it easily. We recommend a brick or medium density breezeblock area oblong with paving slabs on the roof that you can cover with soil. We include a simple design diagram below to give you an idea.
Here are a few more ideas on waterfall design:
Installing the liner and filling your pond
Once the processes above are complete, you are ready to install your liner and begin filling your pond. You will require some large blocks or bricks to weight the sides of the liner. As the water fills, you want the liner to stretch slightly, so lift the liner so there is a gap of around 20 cm from the bottom and use bricks / blocks placed at intervals around the pond edge so that as the water fills, the liner stretches into place. Try to avoid creases in the liner as it fills by making alterations, pulling the liner up manually in places as required to remove the creases. Keep at least 30cm of liner exposed around the sides of the pond, as you’ll want to cover the overlap with large stones that also overlap the water’s edge slightly. This is particularly important for large ponds that are likely to be visited by waterfowl. Their sharp claws can otherwise soon shred a liner.
Planting out your pond
A mixture of deep water plants like lilies and oxygenating plants are essential to maintain a healthy pond and attractive. You will need to position the aquatic plant at the correct depth required, using a good quality aquatic compost to transfer the plants into a larger pot to allow for growth. Always ensure you cover the surface of the compost with a thick layer of washed gravel to prevent fish or ducks from emptying your pot of soil!
The best time to plant out your pond is early spring or summer.
Submersible pond plants are diverse, from broadleaf lilies and oxygenators that provide cover for fish, oxygenate the water and reduce exposure to the sun, to marginal pond plants such as bullrushes and grasses, which are beneficial by removing excess nutrients from the water.
Choose from many different types of floating plants to increase surface cover where the leaves of your lilies won’t get to.
Most of all, creating ponds and water features is great fun for all the family, as is admiring and maintaining the end result.