Rainscape (a garden for rain along our roads)

We must know human beings have destroyed a tenth of natural life on the planet over the past 25 years.

Roads have been a stimulus for growth and development for centuries. They have however had a very negative impact on the earth because of progressive soil sealing. Moreover, the effect goes well beyond the limits of the roads themselves, as they have impact, whether direct or indirect, on forest destruction, pollution, animal life, biological diversity conservation… This is all mentioned by some researchers in an interesting article published on “Science” magazine. We would like to draw your attention to one figure: based on their predictions, the researchers confirm that by the year 2050 roadways will increase by 60% of what they are now. A saying perfectly sums up the situation: “It’s not raining, it’s pouring”. We must take action to solve this harmful trend!

Something, which can reduce the negative impact coming from road construction – especially new roads –, could be a new technology proposed by some road builders. Its name is Rainscape and Takenaka Corporation launched it in August 2016. It is a technology that aims at storing and channelling water which flows along the road surface and seeps through the side layer of roads.

This technological novelty also has an innovative scientific approach, and it is conceptually simple. It must however be installed correctly and given the correct maintenance. The image attached below shows an outline of the method. Rainwater is stored and filtered through materials which also remove nitrogen and phosphorus.


This “garden” for rain is built along the sides of roads – along the space where we normally find milestones – and should not lead to a further enlargement of road space. In this way many goals are reached, the most important of which being the absorbing and channelling of rainwater, particularly when highly intense, avoiding accumulation and run-off.

Have we really made a Columbus-like discovery for sealed surfaces? Easy, now!

Giovanni Poletti, agronomist specialised in urban management of trees, turf, parks and gardens, recommends caution. This technique may indeed only be used in urban areas which can afford costs and maintenance. ‘These systems work (quite) well in terms of storage efficiency, still the problem lies in those polluters which affect the quality of water, think about the amount of hydrocarbons released from vehicles or the nonsensical quantities of de-icing salt being scattered along the roads.

Despite the good intentions and use of those materials, given our situation I think we keep making the same mistake, meaning quibbling about something without really knowing much about it.’

As we wait for new solutions, all we can do is try and limit the building of new roads and settlements.