Amsterdam roofs that not only grow plants but also capture water for residents | Hacker News Reader

Amsterdam roofs that not only grow plants but also capture water for residents

wired.com

66 pointsdivbzero17 comments

In Belgium it is mandatory for new houses to collect rainwater from the roof and use it for your toilet or washing machine, or to use a special well to let it soak into the ground slowly. This is quite cheap actually. The main purpose is to avoid this rainwater to come into the wastewater system.

Interesting - in our country we have street-level stormwater channels which are separate from sewers, and drain straight to streams, rivers and ultimately the ocean. Is that sort of infrastructure not present in Belgium? I can imagine retrofitting that kind of thing into older urban streets may be tricky, but seems like a wise investment.

& apparently they help restore attention on micro-breaks [0] *-*

[0] https://www.sciencedirect.com/science/article/abs/pii/S02724...

The photo shows clearly how when people invest some money ant toke it seriously, a smart landscaper can improve the life of their clients and increase the economical value of a building.

Covering your roof in Sedums (or other Crassulaceae) is not only beautiful, it has some extra advantages.

1) Insulation against scorching sun so you save in air conditioner

2) Protecting the house against wildfire sparks. This things are decent fire retardants. Aeonium and Sempervivum are used traditionally as lightning protection in South of Europe.

They require a careful previous work for designing the roof to stand the extra weight (fortunately Sedum can grow in one cm of soil), and a few extra work for maintaining and weeding (They will need to remove weeds routinely in that humid climate). Also could look untidy in some months or have dry flower stalks, but the benefits overcome the cons

I love the movement and levity that Nassella brings.

I would hope they have some kind of water filtering setup.

Addressed in TFA:

> Green roofs might help soak up some rainwater to hydrate the plants up there, but blue-green roofs go a step further with additional infrastructure that gathers up the liquid, stores it, and dispenses it to the building’s residents for watering plants and flushing toilets.

Humans are good at adapting, so when events like droughts or floods come along, we look at ways to adapt to that.

Some years ago we had a drought here. Now lots of residential houses have water tanks collecting (at a minimum) rain water. Some are supplemented by ground water, via well points etc.

Once you have this, this water is useful in lots of cases. We use it for toilets, watering plants, washing outside spaces and cars, top up the pool, plus other random things like mixing cement or washing the solar panels.

When there's too much rain coming off the rook, and the tanks are full, we route the rest into the ground (literally down the well).

Our domestic water consumption has dropped around 50%.

Although we don't filter it, it "sits" in a tank for several days before being used (and we draw from not-the-bottom) so its pretty clean when we use it. Obviously not drinkable though.

Wow. You make a great point. You got me thinking about those rainwater capture systems for downspouts now. Rainwater hits asphalt shingles and picks up a bunch of hydrocarbons, and then someone uses the contaminated water to grow their tomatoes.

This is shit is going into every water table we have though, all the run off from the roads, tarmacs, roofs, fake grasses, it’s all contaminating the world.

If you grow vegetables in an urban environment the rain will bring a lot of undesired things in any case. Is unavoidable. Regulations (and the complicated plant metabolism) can fix that

Apart of that, is not required to wash the tomatoes directly with the grey water. Just soak the roots and the organism will take care directly of the recycling and classification of water and other stuff. Everything nasty stored in roots, stems or leaves is harmless and equivalent as cleaning it from the environment for free. Only fruits will count. Cells are good at keeping out what they don't like; and store the things that they like.

> If you grow vegetables in an urban environment the rain will bring a lot of undesired things in any case.

Apart from areas with heavy air pollution, rainwater as it falls from the sky is generally clean enough that it's safe to drink. Almost anywhere on the planet.

But! As soon as it hits a surface, it's easily contaminated with anything & everything: bird droppings, lead (used as an additive to zinc) from galvanized corrugated steel, etc etc.

Basically: in most places, rainwater is as clean as the collection surface / piping / storage equipment used.

The standard recommendation is to avoid shingle roofs for rainwater collection, and use a non-toxic metal or tile roof instead.

Ignore the advice saying plant cells or fruiting bodies can "keep out" pollutants; this isn't true across all classes of pollutants, so best to err on the safe side.

Once again they are ahead of the curve. I was already impressed by the road designs limiting vehicle traffic to the outer ring of a city, making it harder to drive in the city center in favor of other transportation options, having scooters, subway, trams, bikes, and accesible walkways as alternatives and then going as far as to regulate noise level!

If only this kind of thinking was available in the US. :/

The confusing array of one-way streets, in Boston, takes care of that.

https://archive.ph/vrRUq

This might explain why the water in our Amsterdam office is only broken in the mornings.

Would be illegal in some states. https://www.familyhandyman.com/article/collecting-rain-water...

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