The Delta Works are one of the Seven Modern
Wonders, They are the largest system of flood defences in the world, and they are currently
being used as the template for many countries on how they should defend themselves against
rising sea levels. But how could such a small country construct
one of the most advanced flood defences? To answer this, let’s take a look at its
history. The Dutch had been building dams and dike
and other flood defences for millenia. In fact, the first settlers of the Netherlands
built their settlements on hills because of the frequent floods. They are called ‘the low countries’ afterall. And the first dams, dikes, and dunes created
by the Dutch were built in the 8th century. But as the Netherlands grew richer and more
populous, the flood defences wer improved. In the 1930’s the Netherlands constructed
the longest dam in the world, the Aflsuitdijk, to protect the central region of the Netherlands
against floods. You can watch my video on that after this
one by clicking on the link at the end of this video. Now that that project was completed, the Dutch
government started looking into plans to dam off the south-western part of their country
as well, right here in Zeeland. Which is the Zeeland that makes New Zealand
‘New’. But they weren’t able to make significant
progress because the Netherlands was busy being invaded by Germany and after the war
the Dutch government prioritised rebuilding the old, rather than building the new. But then everything changed when the North
Sea attacked. In the night from the 31st of january to the
1st of February, exactly 67 years ago in 1953, a storm hit the Netherlands with a ferocity
rarely seen in this part of the world. Because it was the 50s in Europe, many radio
stations, weather stations, and emergency offices weren’t staffed at night. So when the warning was sent out that evening
of an incoming flood, there was nobody there to listen to it… until they heard the water
rushing through the streets, dragging away houses, cattle, and people. While this area was protected by dikes, they
simply weren’t strong enough to withstand a storm of THIS magnitude. They were designed for the smaller regular
floods occuring in the Netherlands. But this storm broke the coastal defences
in 67 locations, with holes up to 3.5 km wide. In total, 1836 died in the netherlands, 70.000
people became homeless, and 200.000 farm animals were killed. The news broadcast the next morning proclaimed
“The sea needed just a single night, to prove how powerless humanity is”. 20 days after the flood, the Dutch government
created a team of experts tasked with looking into ways of tackling the problem of the netherlands
constantly flooding. They called this team of experts: the Delta
Committee. Afterall, the Dutch had already created a
large dam just 20 years earlier. While the South-west of the Netherland was
being flooded, the people behind the Afsluitdijk slept safe and sound. They already had the technology, they now
have the willpower, all that was needed was a plan. But some of you might be wondering why they
called it the Delta works. Well, the region through which most of the
flood came in is called the ‘delta region’ because 3 different rivers end in this region:
Meuse, Schelde, and Rhyne. So the Delta Works is named after the Delta
Committee and the Delta committee is named after the Delta Region… So, we’ve come full delta. The committee spent over 2 years gathering
data and setting up the Delta Plan. Over those 2 years they presented 5 points
on how The Netherlands should improve its flood defences. In total, the costs were estimated to be about
2 billion Guilders, which is about 6.5 billion Euro in today’s money. That doesn’t sound like a lot today. Afterall, humanity possesses far better technology,
far more resources, and far more abundant manpower. But 2 billion guilders in 1955, was a tremendous
amount of resources to devote on a single project. In fact, this was about 13% of the entire
Dutch economy at the time. To put the scale into perspective, if the
Netherlands would try to spend a similar amount of their GDP on a project today, it would
be about 120 billion Euro. That’s enough money for the Netherlands
to fund 3 missions to Mars all on their own, including all the Research, Development, and
infrastructure… at least with Mars the Dutch won’t need to worry about flooding. Now the analyses were completed, the plan
had been laid out, and the costs had been calculated. It was time for parliament to vote on the
Delta Works. With a landslide victory for the Delta-law
in parliament, it passed through the senate in 1958, and a day later was signed into law
with the signature of Queen Juliana. The work could now begin. But WHERE to begin? You can’t do everything all at once, the
Netherlands simply lacked the resources to do so at the time. And so the decision on where to start came
when the committee published their 2nd suggestion: they concluded that the lowest point of the
Netherlands, near Rotterdam, was also the most likely to flood and the most deadly with
3 million people living behind that dike in cities like Rotterdam, Delft, and the Hague. In fact during the flood, a hole did get into
the dike. Whenever people tried to throw bags of sand
in the dike to plug it, the water would immediately drag it away again. Realising the imminent danger they were facing,
the local mayor convinced a local merchant captain to use his 18 meter ship to plug the
15 meter wide hole. Because of the bad weather the ship might
get blown away again. So he rammed the ship into the dike, giving
rescue workers just enough time to fill the hole with sandbags. Without their efforts, millions of people
might have become homeless, rather than ‘just’ 70.000 people. And you can visit the monument they put there
in honor of this captain and the rescue workers. And so when the Delta Committee published
their findings on just how vulnerable this area was, the local governments immediately
funded the flood barrier which the committee had suggested, without waiting for the national
government to approve funding. They built it right here, at the Algerabridge. The flood barriers would be hoisted above
the river to allow ships to pass underneath, but can be lowered into the river in case
of a flood. Next came the largest part of the project. You see, Zeeland was basically a collection
of islands, resulting in around 700km of shoreline which needed to be protected with 700km of
dikes. And so the key priority for the Delta Committee
was to find a way to shorten these 700km to just 80km. They decided to do so by connecting the various
islands to each other with dams, this meant fewer weak spots, reduced maintenance cost,
and increased quality of flood defences. The plan called for the construction of 4
dams where the water from the river could still flow into the North Sea, but the North
Sea wouldn’t be able to flow into the rivers. As well as several smaller dams further upstream
which were needed to divert the flow of the water in such a way so the water flows into
the sea, instead of flooding the area behind the major dams. But as you may have noticed, the most southern
inlet would not be dammed off. This was because this waterway led to the
port of Antwerp. So the Dutch decided that damming one of the
largest ports in Europe probably wasn’t going to make them very popular so they kept
it as is… damn belgians always messing up infrastructure. But this wasn’t the only accommodation made
for the port of Antwerp. You see, ships travelled between Amsterdam,
Rotterdam, and Antwerp. But this plan would make those waterways nearly
inaccessible. So to maintain the level of trade, the Dutch
decided to dig some extra canals to let the ships continue their business unhindered. And so the Dutch began building various dams
simultaneously, starting with the smallest ones. The Delta Committee acknowledged that no plan
like this had ever been attempted. They therefore advised to start with the smaller
dams first in case of unforeseen consequences arising halfway through the building process. While each dam was a little different, the
dams did fall within 3 types of dams. The first type was the tried and tested method
of using a gondola. This was the same method they used when building
the Afsluitdijk I mentioned earlier: they would span a cable across the water, attach
a large claw and used that to drop rocks into the water until they reached all the way to
the surface. Then they would pump sand onto the rocks until
it was filled up completely. But this technique didn’t work in places
with a strong current as the boulders wouldn't stay in place. So they developed a technique where they would
place hollow concrete blocks into the water, be kept in place with a temporary wooden construction,
and filled up with sand. Then they kept placing them next to each other
until they had a dam. To keep them all in place they poured sand
and small stones on top the concrete blocks until they had a proper dam. This was called the ‘phoenix caisson method’. Okay that sounds badass! Engineers are MUCH better at naming things
than historians are. After completing a few of those dams they
had effectively turned one of the Deltas into a freshwater lake. This had the effect that the flora and fauna,
which was used to living in an environment with both fresh and saltwater, was dying out. And the goal was to completely dam off this
area and the construction was nearing completion of this goal. But by the 70s people started caring a lot
more about the environment. And so local fisherfolk and environmentalists
started protesting against this loss of flora and fauna… This reached all the way to parliament when
the radically-progressive Christian Party, made up mostly of young people, threatened
to leave the ruling coalition if the government wouldn’t find a solution to this environmental
problem. So the government decided throw a BUNCH of
money at some engineers and scientists to figure out a solution that protects both the
people and the nature. So a bunch of radically-progressive Christian
BABY BOOMERS helped SAVE the environment… wh… I… Okay Boomers, good job! I wish 20s boomers were more like the 70s
boomers… The new plan took into account that most of
the dam had already been constructed. So they decided to keep the dam in place and
focus on the unfinished parts. Here they would put a storm barrier which
could be lowered during a bad storm and kept open the rest of the time. This way, fresh and salt water mixture wouldn’t
disappear and local wildlife would be preserved. But how do you make the longest surge barrier
in history? Well, the plan was to CONSTRUCT ADDITIONAL
PYLONS!!! They create 65 giant concrete pylons upon
which the engineers could place the actual surge barrier. These pylons were big, took 1.5 years to make,
and had to be made on site. So they used one of the three artificial islands
which were already constructed for the original dam and converted part of it into a drydock
where they could build the pylons. When the pylons were ready, a large trench
was created on the riverbed. Mats were placed on either side of the trench
to prevent the soil from flowing into the trench. Then the sand underneath the Trench was vibrated
to pack the sand together. Now that the riverbed was sturdy enough for
the pylons, they were picked up one by one and delicately placed on the riverbed. Each of the pylons was hollow, so to keep
them in place they were filled up with sand, while on the riverbed they were covered by
stones. Now that the pylons were locked in place,
the engineers attached the barriers between the pylons that will actually stop the waves. With these dams and flood barriers finished,
it would be nearly impossible for a flood to hit this region of The Netherlands ever
again… but there was still one section left. While the delta region was secure, the city
of Rotterdam wasn’t secure. While the first delta work was created in
the city, it needed 2 more just to be safe. They built a flood barrier atop a river, which
was very similar to the first delta work. But the 2nd flood defence was a large system
of dams along the river leading into Rotterdam and the Port of Rotterdam. This system required about 50 km of dams and
demolishing part of the city with historical buildings 400-year-old. This was deemed too costly. So
this time, they let companies compete for the best design that was relatively cheap,
wouldn’t block passage to the Port of Rotterdam, but would keep the people safe. And the choice fell on a unique design: This
storm barrier is one of the largest moving objects ever created by humanity. It had to be built piecemeal and assembled
on site. Due to the size of the individual pieces,
the company had to hire several specialist contractors to get the massive parts they
needed. There would be two barriers, one for each
side of the river. They were designed to rotate, so that when
there was a flood risk, they would slide the two barriers onto the river where they would
meet in the middle. Once in position, barriers would be filled
with water so they slightly sink into the river and can then withstand the oncoming
storm. And so… finally, in 1997, the last of the
Deltaworks were finished. And humanity had shown that it wasn’t so
powerless after all. The construction of all the projects combined
lasted from 1954 to 1997 and not a single one has ever failed since being put into work. While a storm like the one in 1953 hasn’t
hit the Netherlands since, there have been several moments where the Deltaworks were
being closed down to protect against oncoming storms. The Deltaworks were basically designed to
last ‘forever’, in the minds of those who made it. It should literally last centuries with little
maintenance, based on the weather patterns of the 20th century… But recent reports showed that as sea levels
rise and the climate changes, the deltaworks might not be able to stand against the tides
of the future. In a worst-case scenario, the sea levels will
rise by up to 4 meters requiring a complete overhaul of the deltaworks and the Dutch flood
defences as a whole. But don’t worry, I’ll make a video about
that in a few decades if it does happen. But for now, the Deltaworks has kept the Netherlands
safe and will continue to do so for decades to come. If you liked this video then please leave
a like, subscribe, and hit the notification bell. If you have any questions: I will try to answer
all serious questions in the comments. If you want to learn about the Afsluitdijk
or how the Dutch dug up their own country then click on the videos on screen now. This was Avery from History Scope, thank you
for watching.
