Creating a pond
This is not a job to be rushed, so make sure to take into account the following points before starting the process.
Location
Choose the location carefully. Choose a place with a bit of shade, but avoid putting it under a tree, as the roots will spread and damage the walls of the pond. The leaves will also fall into the water.
Leave a perimeter of around 1 m. around the pond to provide acces, and to install stones or plants.
Shape and size of the pond
If it is too small it will have too much variation in temperature, which is not advised if you want to put fish into it.
The depth depends on the surface of the pond. It is not advisable to have the sides too steep. You should have a stair-like slope, with a step every 20 to 30 cms. about 10 to 20 cms. wide. A depth of between 60 and 80 cms. will allow fish to be comfortable in winter and will avoid the water becoming too hot in summer. If you install a water pump to ensure that the water circulates in winter, 60 cms. is enough.
Steps of varying dimensions will permit you to put plant or flower pots of differing sizes into the pond.
Let's identify the different zones :
The bordering zone between 10 and 20 cms. wide permits the development of small plants, whose roots appreciate the mud and water. The roots proivde protection for developing insects, for young fish and for fish whose parents eat their young.
The shallow zone should be between 20 and 40 cms. wide. Plants like reeds, water iris , and underwater plants can be installed here.
The deep zone provides refuge for fish in winter, and water lilies can be planted here.
Filtration
Don't forget about filtration. If you wish to install fish, filtration is recommended. This will ensure that the water remains clear, preventing it from becoming green. It also ensures that the water circulates, thus oxygenizing it, and it will prevent the surface from freezing over in winter.
You can filter ecologically by installing the filter in a container placed outside the pond filled with lava stones.
If you don't want a filter, think about using a pump to move the water around and maybe for feeding a fountain or a cascade. This will bring the pond to life, and the sound of guzzling water is quite pleasant. But don't create a torrent, as the neighbours may not appreciate this !
Lining the pond
First, stabilize the walls with a layer of gravel, then a layer of sand, and finish with a layer of cement, to solidify the structure. This will ensure theat the pond will last longer, and will resist the growth of surrounding roots and the subsidence of the ground.
To waterproof the walls, different materials are available :
If you choose a premoulded pond, ignore the above advice.
Concrete : perfect waterproofing can be obtained by laying down layers of cement, the layers being thinner and thinner as you proceed.
The least expensive and longest-lasting solution is a PVC lining. To calculate the dimensions necessary for a pond 60 cms. deep with a 30 cms. border, add 2 metres in width and 2 metres in length.
A rubber lining , more expensive than one in PVC, will last longer, as it is more flexible.
Whichever lining you opt for, place a layer of garden felt beneath it.
The test filling
To make sure that all is in order, fill the pond to test the waterproofing and the level of the water. It is still possible to make some adjustments to the edges of the pond.
This is also the time to test your filtration system.
Test it over a few weeks.
