Drainage in gardens

Does your garden regularly get waterlogged, making it difficult to maintain a pretty lawn?

Install drains to guide all this water to healthier soil.

What is a drain?

A drain is a system installed in the ground to drain water, with the aim of mechanically drying out the soil.

/Here we are talking about drains for gardens, not for buildings !

When should drains be installed?

It is advisable to install drains when you encounter various signs in your garden:

• algae/lichen in the lawn
• plant asphyxiation
• constantly muddy ground
• large, visible puddles lasting more than 12 hours (in an unassigned location)
• capillary rotting of walls

 

Why install a drain?

The water that stagnates in the soil is a reserve of water trapped by the earth.
In this case, the soil is often clayey, and its composition creates fine layers of water at the microscopic level.

As a result, water has difficulty passing under the various lower zones, becoming saturated by quantity and appearing immobilized.
What’s more, stabilizing this soil is complicated by the fact that water is thermally reactive.
In winter, the water swells and enlarges the earth’s cavities, and in summer it evaporates, creating crevices in the clay soil.

 

Will this change the composition of the soil?

With the water removed, the soil will be naturally desaturated and will be able to change little by little.
Plants will be less stressed, will know where to find water and will no longer rot; they will put more energy into modifying the soil.

What can we do with this water?

It’s usually rainwater, so if it’s harvested, it can be reused in the garden in case of drought, for example.

 

What techniques are available?

Connected drains

The connected drain is the most classic method.
The most economical way is to use PVC pipes and drill them.
Placement is preferably in the shape of a cob, or according to the terrain.
PLAISIR VERT prefers to use PVC drains surrounded by coconut fibre to filter the water and avoid the clutter of holes or Fastdrain.

To install the herringbone drain, you’ll need to make herringbone-shaped trenches more than 50 cm deep, install geotextile sheeting, lay a 10 cm bed of gravel and then lay the drain to be coated with gravel and sheeting.

The point of the spike should be directed towards an area where water can drain away.
Guided water can flow into the building’s pipes, to a nearby outdoor area (e.g. fields, woods, etc.), to a lost well, or to a water reservoir.

A lost well is a room buried in the ground that collects water guided by drains.
The lost well has no bottom and therefore creates a recovery chamber before it can be assimilated by the earth’s lower zones.

In other words, it allows the surface zone to be drained of water, and the lower zones to be fed as required.

A water reservoir is a room buried in the ground that collects water guided by drains (with or without water collectors).
The water reserve has a bottom, creating a chamber where water can be recovered for later use.

FastDrain

FastDrain is used on the surface (10-20 cm).
Just 6mm thin, it has a discretion that no other drain technique can match.
Consisting of a three-dimensional PE-HD structure wrapped in a non-woven sock, they act as a complement to direct water to existing drains.

Lost mini-wells

PLAISIR VERT’s experience has led to the construction of several mini lost-well systems.
Made of stone, sand and soil improvers, they are buried “capsules” that manage water vertically.

This is a technique to be used as a final complement if drainage with connected drains remains too light.

The downside is that, over time, settling can occur.
By then, however, the earth will already have undergone its sanitization, this system will have become useless and all that’s needed is to make up the difference.

What result can we expect?

Results are immediate after installation.
Normally, the ground is no longer waterlogged and walking is possible after rain without muddy shoes.

What if it isn’t?

If there’s still water in the system, the weight of the system needs to be increased.
It also remains to be seen if this rainfall is not exceptionally heavy, so check after several periods of rain.

What to look out for

Installing too much drain can dry out your floor and create a reverse problem.