Create a natural pond in your garden

Pond location

Before you start digging your pond, you should choose its location carefully.

Opt for :

• a clear, sunny spot : south-facing if possible. Light and warmth are essential for the development of life in your pond;
• an area away from trees : roots could slow you down when digging the pond and create holes in the pond lining (liner, clay…). Also, leaves and needles that collect in the water will acidify and cause eutrophication (increased nitrogen and phosphorus) of your pond water, which will kill the wildlife living there.
• a location away from houses or human structures : foundations and pipes are obstacles to digging. In addition, a pond will obviously bring moisture to buildings. However, it is pleasant to have a refreshing water feature near a terrace. Find a balance!
• a spot near a wild area : so animals can colonise your small pond safely. An area that is too neatly mown is like a motorway to cross for an insect or an amphibian. Keep that in mind!
• and, if possible, not in a thoroughfare : especially if you have young children. Although safety grilles can be fitted to prevent accidents, choose a quieter, more secluded spot, which will be beneficial for the pond’s small wildlife.
• the wettest, lowest part of the garden : water will collect in the lowest part of the garden. Your pond will therefore fill more easily there

Pond sealing: different solutions

Different methods for sealing a pond are available. Choose according to pond size, desired durability and budget:

• EPDM liner (0.5 to 2 mm thick): most practical and durable option (lifespan about 50 years). This type of liner is tough, easy to install and easy to repair. For small to medium-sized ponds. Best value for money.
• PVC liner (0.5 to 0.8 mm thick): economical option but less durable and harder to install because less flexible.
• Clay blocks: inexpensive, easy to install and repair, very natural, suitable for ponds of all sizes but fragile because sensitive to frost and drought. A viable option in naturally heavy, damp soil.

To calculate area required for a liner (and for other layers: mesh, geotextile, …).

L = length to allow for = maximum planned pond length + 2 × maximum depth.

l = width to allow for = maximum planned pond width + 2 × maximum depth.

Example: for a bean-shaped pond occupying 4 m in length by 2 m at its widest point, with a maximum depth of 1.2 m, we obtain:

L = 4 + (2 × 1.2) = 6.4

and

l = 2 + (2 × 1.2) = 4.4

We therefore need to order a liner 6.4 m long and 4.4 m wide. Allow a little extra, just in case.

Practical steps: dig pond, lay liner

Equipment to prepare

• Spades, shovels, picks… even a mini-digger if you can hire one,
• Mason’s level or water level to check levels regularly
• One or more wheelbarrows

but also :

• Sand, several dozen kilos.
• Galvanised chicken wire mesh: same area as waterproofing surface
• Geotextile felt: same area as waterproofing surface
• Stones and wood logs, if needed
• facultative: Ecolat edging and Ecopics

and above all :

• Friends, family : digging a pond or basin is a real adventure! Don’t tackle it alone… (and bring food and drink!).

Digging the pond

Excavation should be carried out so that different levels are created. A deep area at least one metre deep will help keep a frost-free zone (to some extent). Creating different levels will accommodate different types of vegetation: submerged plants, floating plants, semi-aquatic plants and marginal plants. The deep area will also provide a refuge for animals that will not dry out in summer and whose temperature will remain more constant in winter.

please note : best time to dig a pond is early autumn. Autumn and winter rain will fill it quickly and you’ll already see some insects in the pond by early spring. For planting, you can start with marginal plants in autumn but other plants should be introduced in spring when frost is no longer a risk.

As for pond shape, it doesn’t matter: be creative! For a natural-looking pond, however, create simple curves so it blends into the garden.

In practice :

• Mark out pond outline on ground with a hosepipe or stakes
• Start digging at edges first : create shelves and a deeper hole
• Keep excavated soil to one side : you’ll use it later. Put it on a tarpaulin to avoid damaging lawn.
• If you have a slight slope, you can fit an Ecolat edging to make up the level. This edging screws onto Ecopics driven every 50 cm into ground. Make sure it’s level using a water or spirit level.

Ecolat edging to level ground if needed

• Remove all stones and other sharp materials that could puncture liner
• Lay hexagonal mesh wire : this mesh prevents voles, moles or even muskrats from digging holes and getting through your liner or clay.
• Cover mesh with river sand to even out surface
• Place geotextile : to keep a buffer zone between mesh and liner and prevent mesh puncturing liner.

Laying geotextile

• Lay liner gently : if you must walk on it, do so barefoot to avoid damaging it.
• Fill with water or wait for pond to fill a little so liner can settle into place.

Filling pond after laying liner

• Once pond is full, secure liner by burying edges under lawn, turning edges into soil or, more simply, placing large stones or heavy wood logs around perimeter.

Stonework to hide liner… now just planting to do!

• Replace soil around pond : both to hold liner and to create substrate for marginal plants. Feel free to throw a few handfuls of soil into water and onto submerged “shelves” to aid planting.
• Plant your plants or wait for them to arrive naturally, if you are in region that still contains natural wetlands.
• Enjoy pond for many years to come.

Filling with water and planting plants

Filling with water

• Rainwater : it’s the simplest, most economical and most natural option but it’s also the slowest technique depending on rainfall in your region.
• Water from a tank : if you are lucky enough to have a rainwater tank, do not hesitate to use its water. Only drawback, a pump will be needed to transfer water from the tank to the pond… which may not be located twenty centimetres from the tank.
• Mains water : it’s expensive and full of chlorine (and sometimes other things too depending on the age of your plumbing…) but it’s quick. Simply wait a few days for the chlorine to dissipate before installing your plants and job’s done.

please note : to be thorough, first rinse water can be used in the pond then pumped back. This operation will help remove any pollutants that persist on artificial materials: EPDM, polystyrene tub, fibreglass, …

Planting vegetation

Not all aquatic or semi-aquatic vegetation occupy the same position in a pond; placement depends on their ecology.

• Submerged plants : often oxygenating, these should be placed in the water ;
• Floating plants : very ornamental, they will cover part of the water surface. They should therefore be placed in the centre of the pond ;
• Semi-aquatic plants : these plants should have their “feet” in the water but not be completely submerged. Plant them in shallow areas at the edge of the water feature ;
• Marginal plants : these plants appreciate moist, even marshy soil but not direct immersion in the water. They should therefore be placed on the banks around the water feature.

Planting aquatic plants

A natural pond with or without fish?

Natural pond

Unless your pond covers several ares, forget about fish. Sorry… In a small area, fish will soon eat everything that moves in the water: insects, crustaceans and even the amphibians. Which is a shame when you want to preserve a little biodiversity at home.

Of course, if pond is of a considerable size, ecological balance can be established and fish as well as other wildlife can live in near harmony. Each species regulating the others without total eradication of any sort.

A natural pond quickly becomes populated by a variety of wild fauna, so it is unnecessary, dangerous for the animals and even outright illegal (in the case of amphibians in particular!) to take animals from the wild to “rescue” and keep them at home.

Some pond regulars: dragonfly, frog and backswimmer

Don’t worry excessively about mosquito invasion. Indeed, if your natural pond hosts insect and amphibian predators of mosquitoes, you won’t have problems on that front. The mosquito problem mainly concerns stagnant water with no other life than dipteran larvae: plant saucers, old tyres, forgotten containers, …

One last word: frogs croak during mating season (Scoop!). If you are a light sleeper, avoid placing a natural pond near your bedroom window. In any case it does not last long and amphibians are under such pressure from loss of their natural habitats that one or two sleepless nights are nothing compared with saving species threatened with extinction.

Please note : surprisingly, even if no fish are introduced into a pond or basin, fish inevitably turn up over time. Do not blame your children or a supposedly ill-intentioned neighbour! It is simply that fish eggs and sometimes even some fry have clung to the feet of birds that came to paddle in your “puddle of water”. A sort of one-way school-run for young fish. You will no longer look at herons or moorhens the same way…

Legislation and safety

And what about legislation?

If you dig a modest-sized pond that is not intended to serve as a swimming pool, planning permission is unnecessary. However, check with your local council to find out local regulations regarding these small works. You can, if necessary, submit a works notification to inform neighbours of any disturbance caused, especially if using an excavator.

However, we recommend discussing your project with neighbours and mentioning the possibility of being woken by frogs’ croaking or by an influx of charming dragonflies into their gardens. Some will be delighted, others less so (nature can make people anxious). Always try to explain and aim to keep good neighbourly relations wherever possible.

Can a pond be dangerous?

A small pond, even if shallow, represents a risk of accidents for very young children. As with pools, you can protect it with a fence. You can also fix an iron grille a few centimetres below the water surface. This will eliminate any danger.

Children do, however, very quickly understand the notion of danger; take time to explain why they must remain calm near a body of water: for their safety and to avoid disturbing the little world that has made it their home.

Protective grille

Ideally, introduce children early to the beauty of nature by organising a mini pond-dipping activity using an improvised net made from an old chinois (kitchen sieve!) attached to a broom handle. You can catch small creatures to observe for a few minutes in a tank. To transfer animals from net to tank without trouble, use a paintbrush and be gentle — a leg can come off easily… Remember to return your little finds quickly to the pond, their original medium.

Avoid handling amphibious animals if possible! Not to avoid a hypothetical disease or poisoning (yet another silly urban myth!) but mainly because these animals have no natural protection for their skin (hair, feathers, scales, …). Handling them does them no good, unless your hands are very wet.