Tag Archives: Green

Live with water, don’t fight it

In 1953, the dykes broke. One of the biggest disasters the Netherlands has ever suffered. Since then, we managed to set up one of the most extensive flood protection projects in the world. Our feet have been dry ever since.  But, the tide may be changing. The Netherlands will get hotter, drier and wetter. According the Climate scenarios from the KNMI we will see more and more extreme rainfall towards 2085. Next to that, in between these extreme events, there will be dry periods. Whether you like this or not, it raises the question: ‘’Are our cities ready for the future?’’

Flooding in ‘de Kooi’, Leiden

It is not just a future scenario. It is happening already. Extreme showers will happen more frequently and will be heavier. This leads to certain problems. For example, in cities like Leiden, the sewage system isn’t able to cope with the extreme amounts of rain that will fall during short periods of time. This will result in flooding in streets and houses, which leads to lots of damages. Already this has happened in Leiden.

Cities are most vulnerable because of increasing urbanization. This causes problems with increased flash flooding after sudden rain. As areas of vegetation are replaced by concrete, asphalt, or roofed structures, the area loses its ability to absorb rainwater. This rain is instead directed into the city sewage system, often overloading it and causing floods.

Example of a wide ditch

Municipalities can take measures to prevent the streets from turning into rivers. Some more natural examples include, more green and wide ditches/ponds  in suburbs to allow the ground to take up more water. On the other hand, a more mechanical solution is building surface water drainage systems to relief the sewage systems by transporting rain water to rivers or basins.

The solutions named above may not always be possible. For example, there might not be enough space for creating green areas, which is the case in Noorderkwartier, a district in Leiden. I think especially in those areas it is vital to let the citizens know what problems the council is facing in protecting them. With the right incentives, communities can transform their own neighbourhoods in flood save and sustainable places to live. Below are some solutions people can take to achieve this:

  • Green open gardens. Paved gardens direct water straigt into the sewage system. Green gardens on the other hand, absorb water and also look more attractive.
  • Installing water butts. Green gardens need water. Instead of tapping fresh water, a more sustainable way is to collect rain water. If all houses in a neighbourhood have one, it might just be enough to take up the first beating of a heavy shower. A more advanced idea is the collection of rainwater in large tanks and use that water in a so called ‘grey water system’ (see picture below).


  • Green roofs. This is a more challenging solution. Roofs are large surfaces, which potentially can take up a lot of water if planted with grass. However, roofs must be able to support the weight of them.

Let’s embrace these solutions and turn our paved surroundings into green sustainable neighbourhoods where rain is welcome.

After us a garden


Après nous le déluge’ was alledgedly said by Madame de Pompadour a French aristocrat from the 18th century and mistress to King Louis XV of France. ‘Après nous la deluge’ or ‘after us, the deluge’ roughly means ‘I do not care what happens after we are gone’. However, I am glad to say that a lot has changed since that statement was made, but a different threat looms over us.

By now the majority of the population is aware of climate change and cares about the state in which we leave the world to future generations. Furthermore, we ensured that chances of heavy flooding are as slim as the chance of experiencing a guillotine induced death. But there is a different water-based threat to suburban life and it arrives in the form of heavy rain fall. Spells of rain will become short and severe, instead of long-lasting and drizzly, this is caused by climate change. Therefore, we need to make sure that our inner-city drainage can handle a lot of water in a short period of time.

I personally live on the outskirts of Leiden in a neighbourhood with a lot of space for plants and trees to grow. After the rain, I can see puddles but after a night or a part of the day I notice that all the water is gone. When travelling to the city centre the predominantly green environment changes into brownish manmade surroundings with more Apple-stores than apple trees, and more Lush-soap shops than lush vegetation. After a spell of rain, you can still see puddles for a long time. Heavy rainfall already causes problems in certain parts of the city, where rainwater can reach over the thresholds of waters and flood into people’s homes. It seems to me quite an inconvenience when a whole neighbourhood collectively shudders and frantically reaches for the hosing-bucket at the sight of a low hanging dark cloud!

Clearly a solution is needed for the watery threat from above, rather sooner than later I would like to add. I personally think that where possible green spaces must be created. So-called raingardens or Sustainable Urban Drainage System (SUDS) can be offer a pretty solution to an ugly problem. Raingardens aide in the capture of water in a natural manner, and making plants and flowers grow and bloom creating small bits of green or parks. Plants and flower store water in their roots, but their roots also bind the soil protecting against soil subsistence. Raingardens make the underground struggle against excess water visible and part of our day-to-day lives. The presence of nature in the form of flowers and plants also have an effect on the psychological wellbeing of people. A certain quote from Ladybird Johnson comes to mind when writing about raingardens ‘Where flowers bloom, so does hope’. For the inhabitants of regularly flooded neighbourhoods this might be the hope of permanently keeping their feet dry. Let us leave a garden for future generations to enjoy!

Awareness is created by explaining what  raingardens do, but the benefits are mostly noticeable by the absence of flooding after heavy rainfall. If you are interested in raingardens or other forms of Sustainable urban drainage systems I would recommend reading the following articles.



The end is nigh! The end is nigh!..

The more I learn about climate change, the more I feel like walking the streets, wearing a sign that says:”The ending of times cometh. Repent!” I want to ring doorbells to ask people if they heard about our Lord and Savior; Geo-engineering. I want to spread pamphlets that show failed harvests, forest fires and drowned polar bears.

But this is the 21st century. So I will do what everyone with an opinion does these days:                     put it on-line.

Even though climate change has become a fact instead of a believe, we still need to preach the gospel of the greenhouse effect and the effect it has on our lives.

Thereby preventing further damage to the planet and start protecting ourselves against the consequences. Because a change in climate means a change in local weather. For the Netherlands this means that the temperature will increase a few degrees and that we’ll have problems with water. (Because the Netherlands will always have problems with water.)

First, the intensity of rainfalls will increase, overflowing the rivers, sewers and eventually your basements and ground floors with heavily polluted water.

After the rain come long periods of drought. A drought that causes a shortage in clean drinking water and dry land. All local nature that is not well adjusted to dryer circumstances will have a hard time surviving. Depending on the soil, buildings have a higher risk of collapsing due to the sinking of dry ground and rotting wooden fundaments.

…So let’s build an arc.

As the surface of the earth becomes increasingly covered in stone and concrete, water has nowhere to go but to the sewage. There rainwater mixes with waste water and will need to be purified. It also has the potential to exceed the sewers capacity, causing flooding.

There are many ways to collect as much water as possible before it reaches the sewer.      So, here are some Doomsday-Prepping-tips to deal with this liquid inconvenience.

By growing plants instead of stones in your backyard you increase the amount of water that the ground can hold. Green roofs also store water and work great as house isolation. (Saving both the environment and your wallet!)rain-garden-how-to

Rain barrels and ponds can collect a large amount of rainwater.even-better

Hydroblocks do that as well, but they have the advantage of being underground and slowly releasing the water.hydroblock

Where flood prevention only works if it is done communally, water storage has an immediate personal benefit. As the dry period begins, there will now be a large amount of collected water available. The greenery will maintain itself and local wildlife for a period that increases with size and create a more pleasant local climate. All collected water can for example be used for washing machines and toilets and around the house when tap water becomes scarcer and more expensive.

Hydroblocks will slowly release water into the dry ground, preventing the sinking of houses and roads and the rotting of fundaments.

So, be prepared! The end is nigh! (Or, at least, wet feet are.)

Continue reading The end is nigh! The end is nigh!..

Fossil to turbine, turbine to kite


Planete energies defines energy transition as “the shift from current energy production and consumption systems, which rely primarily on non-renewable sources such as oil, natural gas and coal, to a more efficient, lower-carbon energy mix.1” This is a lot easier said than done, especially with lots of discrepancy amongst scientists on various approaches and unforeseen problems. However, they do agree on one concept known as the energy trilemma:



The energy trilemma looks at how policies made need to balance three different aspects: security, sustainability, and affordability. The easiest way for change to be made is for innovative technological breakthroughs. These would hopefully raise energy efficiency, lower the cost, and not harm the environment, thus solving the trilemma.

One particular solution was a concept brought up many years ago but never fully took off. Saul Griffith talks in his short Ted talk about the efficiency and usefulness of kites to capture wind energy. Griffith explained how turbines are limited in how much taller they can be, however kites can go significantly higher, which is where more wind is.3


You can watch his 5 minute Ted talk here

Griffiths isn’t the only one who is advocating for kite energy. Several other companies around the world are hopping on this bandwagon:

Kitenrg, an Italian company, is working on making kites that reach up into the troposphere where there is significantly more wind, thus creating more energy. It is harnessed to the ground with two cables as well as an electric generator.5


Kite Power Systems of the UK explain the added benefits of low cost that government subsidies won’t be needed and that unlike windturbines, these can go places the turbines can’t. They have already set up a small station in Essex as well as a 500-killowatt system near Stranraer in Scotland.6

Makani, a company bought by Google, focuses on making wind energy more affordable and efficient which will ultimately eliminate fossil fuels. This kite is slightly different than the previous two examples. The kite is launched from a station on the ground and reaches heights of 800 feet with the help of rotors acting as helicopter blades. Power is generated by flying in circles higher up in the air.7


As shown above, wind kites come in a variety of shapes and sizes with several different companies from around the world trying to propel this solution everywhere. Kites could be a key concept to help Leiden transition from a city of fossil fuels to a city of renewables. This is relatively cheaper and simpler than current wind turbines. Additionally, since it is not feasible for Leiden to rely heavily on wind turbines as an option for renewable energy, this could be a key solution.

Wind kites have the potential to be the technological breakthrough that solves the energy trilemma for renewable energy.





  1. http://www.planete-energies.com/en/medias/close/challenges-energy-transition
  2. Picture: http://www.arup.com/low_carbon_energy_the_future_is_now
  3. http://www.ted.com/talks/saul_griffith_on_kites_as_the_future_of_renewable_energy/transcript?language=en
  4. Picture: https://www.faulhaber.com/global/markets/environmental-safety/energy-kites/
  5. Picture and Website: http://www.kitenergy.net/technology-2/key-points/
  6. http://www.independent.co.uk/environment/kite-power-station-scotland-wind-turbine-plant-electricity-a7348576.html
  7. Picture and Website: http://www.alternative-energy-news.info/makani-energy-kite/

From leftover to luscious meal

Leiden: the city of students, which are the future of our planet. Leiden is also a possible frontrunner in sustainability. These two aspects are opportunities to make Leiden a sustainable city, like the municipality wishes for by 2030. In a city with an abundance of students, loads of food is eaten. Because without food, there won’t be any nutrition for the brain to study. And let a diet just be where there is a lot is to gain in sustainability.








Of all the food produced, the percentage of food that is thrown away is estimated between one-third and one-half. That just makes your stomach turn, right? Certainly when you think of it this way: most of the food that is thrown away is still good and edible. It is lost in production, during transport or in our own houses. A movement towards a circular economy would be a more efficient way to use food. In a circular economy, raw materials are optimally used. Reduce, reuse and recycling are keywords for this system: reduce the amount of needed raw materials; reuse products instead of buying new ones; and recycle as much as possible. A circular economy can for example include the use of leftovers.

In Utrecht, Amsterdam and The Hague special pop-up restaurants have popped up for leftover food, called Instock. Leftover doesn’t sound very delicious, but it really can be. Products with today’s date from supermarkets cannot be sold anymore, but can still be very tasty. Other examples of thrown away food are ‘ugly’ vegetables.

‘Ugly’ vegetables

Producers think the products need to look good for the consumers, but when the food is on your plate, you will not taste the difference between a round pepper and one with a bump on it. In the United States of America is even a business in ugly vegetables! And when an apple is beginning to bruise, they can still make apple pie out of it. But, the stores cannot use products out of date, because that’s not in line with the law.

Of course, this is not a fully circular economy. It will not be feasible to create a complete full circle of the food web, because there will always be a percentage of produced food that’s simply not tasty anymore. You also have products that do not expire quickly that always needs to be bought in pop-up stores like these. In Instock, it’s about 20 % of the dinner that must be bought, like oil and dairy. The leftovers of the leftovers – products out of date or bruised – can be used as fuel (bio-gas) or fed to the animals in the petting zoo. In this way, even these leftovers can be used well. It is a good start into sustainability.

For Leiden, a pop-up store like Instock can be an opportunity. As a student, I like to eat out. In this restaurant, you will get a prepared three-course meal for little money. There are enough supermarkets to provide the restaurants in their needs and enough students as customers. I would definitely eat there!

Citizen Involvement wanted: without Citizens’ knowledge?

The streets in the city of Leiden, can be quite beautiful, yet one can’t help but notice that most streets you walk down are barren of any natural greenery. A city that naturally has plenty of rainwater to sustain plant life without the use of artificial watering devices, somehow is devoid of lush greenery. How can this be? The all-encompassing tiling that has been laid out all throughout the city has prevented any plant life from forming naturally. Sure, there may be trees here and there, encircled by bricks, yet thriving gardens, and green walkways are far from being seen.

Let’s take a look at one of Leiden’s most ‘green’ streets : “de groenesteeg” (pictured above): even a street that is named the green street, and is well known for being filled with plant-life, fails to have even one full yard of open earth surface. There may be many pots and other plant carriers, placed on top of the tiled surface: but where is the connection to the earth underneath? In Leiden’s Agenda for 2030 sustainability goals, the municipality clearly states that they’d like to push citizen participation in improving biodiversity within the city. In the past year, they have already introduced subsidies to reimburse and financially support residents with un-tiling their front gardens, replacing the tiles with a green, flora filled garden. Measures have already been taken to encourage resident participation in improving biodiversity in the city. But, how effective have these measures been thus far? I decided to get hands-on and investigate how the residents themselves experience the municipalities attempts at increasing biodiversity, by going through the streets of Leiden city, and knocking on residents’ doorbells. The conversations I had with the locals themselves, opened my eyes to quite a number of things regarding this subject. Not only concerning the resident’s awareness of the cities agenda, but also how the residents themselves feel about biodiversity loss, green spaces, and un-tiling their front gardens.


Let’s begin with the most discouraging insight: none of the residents that I interviewed knew that getting rid of the first 20 cm of tiles in front of their house was legal to do,  let alone that there are subsidies available for un-tiling their front gardens.


One woman around 60, living in the Uiterstegracht, stated that she had asked the government about 10 years ago, if she could un-tile the front of her house, to which they refused due to fear of the roots of plants destabilizing the tiles surrounding it. The municipality clearly had a different agenda 10 years ago, and yet nothing seems to have been done to inform citizens of their new views on what is encouraged, allowed, and no longer condemned. This woman clearly wished to un-tile her front garden, but has never done so due to thinking it was an illegal act.  When I informed her of the subsidies now available to encourage the re-greening of tiled areas, she was astonished. “Now I will definitely get the front of my house un-tiled”, she exclaimed, explaining that it not only is more convenient than having pots in front of her house, but also helps with water retention, preventing run-off. This woman was clearly knowledgeable about sustainability topics, and yet she was completely unaware of any of the municipalities endeavors regarding sustainability. And I dare say: that is truly a shame.quote-the-world-is-not-a-problem-the-problem-is-your-unawareness-rajneesh-56-46-62

Indeed, not one of the residents I interviewed were aware of Leiden’s Sustainability Agenda. The good news is that once I informed them of Leiden’s agenda, all voiced their approval of Leiden’s plan to become more sustainable. So indeed, it seems that residents tend to be pro-sustainable actions when it comes to biodiversity and re-greening the city. The problem is, a lack of knowledge, and surprisingly, I have found, a lack of space for parking bikes. The two residents I interviewed who were pro-biodiversity yet would not un-tile the front of their houses even with help from a subsidy, said that it would deter them from being able to park their bikes in front of their house. Thus I think Leiden has overlooked two important aspects in their plan to encourage citizen involvement regarding biodiversity: the need for the citizens’ awareness, and solutions regarding bike parking.  BerlinBikeShop8x6.jpg

Green roofs to make Leiden future-proof!

If we look at climate adaptation of the city of Leiden, the main goal is not to fight nature, but to work together with it. While climate is changing, life in the city changes as well. The more extreme weather causes floods, droughts, higher and lower temperatures and the city cannot always handle this. That is why it is necessary for the city of Leiden to adapt to the climate. One way to do this are green roofs. If you do not know what a green roof is, watch this video to know all the basics.

Green roofs can solve a lot of problems that climate change brings. Green roofs absorb water during heavy rainfall, so that sewers do not overflow. Green roofs keep the inhabitants cool during the hot summer and most of all, it keeps people dry. Also green roofs can provide a habitat for wildlife to increase biodiversity and it can increase the air quality in cities (Oberndorfer et al. 2007). Green roofs mean less consumption of energy because it keeps you warmer in the winter and cooler in the summers.

Green roofs will become also more economically attractive in the future. Now a green roof is in comparison with a traditional roof 10-14% more expensive at a life span of sixty years. If the climate keeps changing and extreme weather will occur, the green roofs will become more and more attractive to prevent flooding and extreme heat in cities because of saving money on energy consumption and other techniques to prevent flooding (Castleton et al. 2010). There is an initiative in Leiden to get more green roofs. It is called Groene Daken Leiden and helps citizens to get subsidies for green roofs. It is based on an initiative of Amsterdam and it is making great progress. If you want more green roofs in your neighborhood you can ask them for help to get subsidy. Then you can help Leiden to adapt to the future in a more sustainable way for only a small fee. In the picture below you can see a project they did at the Boerhaavelaan in Leiden.


The benefits of green roofs are endless for the environment and for the people living under them. Green roofs are a great way to get more green and plants in the city and increases the aesthetic value of neighborhoods. Green roofs are also a great method to reduce noises and living in a busy city this can be of great value! Green roofs does not demand a lot of maintenance. Only in periods of drought is it necessary to water your roof, but even a dryer roof will keep all it functionality and benefits (Getter & Rowe 2006).

Leiden is a very dense build city and has a strong heat island effect. This means the temperature in the city is on average 3 degrees Celsius higher than in rural areas. With rising temperatures because of climate change this can cause a lot of problems for the city, such as droughts and higher mortality rates during heat waves. If we want to keep the city a nice place to live, things have to change for future generations. Green roofs can provide a solution to make Leiden future-proof!