As a garden owner, you have a key to solving an urgent problem; peak showers and their consequences. By constructing a wadi or placing underground infiltration crates in your garden, you can store rainwater. And besides that, there are also simpler solutions …
If the streets are flooded after a heavy downpour because the water cannot flow into the sewer fast enough, this is annoying. Much more annoying, however, is that this causes so-called overflow problems. The sewer system becomes overloaded, the treatment plant can no longer cope with it and polluted water ends up in the surface water.
And that is bad for the environment.
Garden as a sponge
Now you could say: nice to know, but what does a gardener have to do with this? The answer is simple: garden owners hold a key to
Solving this increasingly pressing problem.
All in all, we have about 250 square kilometers of a garden in our country.
These gardens are indispensable for collecting rainwater, especially in the city. Rainwater falling on the pavement pollutes the sewer. But rainwater that ends up between the plants sinks into the ground. A garden is a sponge that absorbs water and releases it via evaporation.
Plants, green roof, disconnecting downspout, facade garden
- There are several ways to make better use of the sponge capacity of gardens. First of all, by using as many plants as possible. After all, the less stone the better. You can also replace (part of) the pavement with semi-pavement, which does allow water to pass through.
- What also helps is the construction of a green (shed) roof. A green roof or roof evaporates 70% of the rain that falls on it during the year. In addition, it ensures that the water flows into the downspout with a delay.
- A relatively little used, but very effective measure is the disconnection of the downspout (s). The water that comes off the roof then no longer flows into the sewer, but directly into the garden.
- Create a facade garden: see this article for more information.
Collecting the roof water in your own garden creates opportunities and possibilities. But disconnecting is not something you just do. First, accurate calculations must be made. The soil needs to be permeable enough and you need to know exactly how much water will come off the roof when it rains. The larger the roof, the greater the required storage capacity.
A fun and highly visible way to store the rainwater is to construct a wadi (water drainage through infiltration). Simply put, a wadi is a ditch in which rainwater is temporarily collected. The permeability of the soil, the construction, and the size of the roof determine how much water ends up in the wadi and how long it remains in it. It is often thought that a wadi is a kind of swamp, but in practice, wadis are dry 85% of the time.
Underground infiltration system
There are also underground infiltration systems in which a large amount of rainwater can be collected. There is nothing special to see in the garden itself, but during a heavy rain shower such a system fills up with water.
If you are considering disconnecting the downspout, you can contact various institutions for information. Some municipalities provide subsidies for this. Two garden designers who specialize in the design of ‘climate-proof’ gardens are Elke Blänsdorf and Anneke Beemer from De Groene Verdieping. This is a
A partnership of garden designers from the municipality of Amersfoort, who work together for this purpose with the municipality of Amersfoort, the Water Board, and Operation Steenbreek.
Last year, De Groene Verdieping designed several gardens in which all the rainwater
Is collected. They are very different, but in both cases, the owners have not regretted their decision for a moment, they enjoy the result to the fullest.