The closing of the Netherlands coast
Last but not least
Sealing off the many estuaries: the shortest possible line of defense
The idea of shortening the coastline of the Netherlands is by no means
new. Originally the coast was very irregular owing to the many
river mouths, sea-inlets and tidal creeks. When people started making
dikes, they made them as short as possible, damming the lesser creeks
immediately. Later larger creeks followed, hence the many names ending
in "dam"Amsterdam: the dam in the river Amstel; Rotterdam: the
dam in the river RotteSchiedam: the dam in the Schie, etc. It is estimated
that the first dikes in the Netherlands had a total length of some 1500
miles.
In 1840 the "salt" coastline was still 1230 miles long and by 1930
this figure had been reduced to 1030 miles. The closing of the Zuider Zee
in 1932 shortened the coastline considerably to 840 miles.
Now, in 1954, the length is 800 miles, because since the late war we
have closed the Brielse Maas (a practically worthless mouth of the river
Rhine) and the Braakman inlet off the Scheldt.
Ultimately the coastline may be reduced to about 300 miles, but the
work involved is so immense that its completion will take us beyond the
year 2000.
When Netherlands engineers speak of closing the coast, this does not,
of course, involve the closing of the river Scheldt, the Rotterdam Water
way, and the river Ems, as this would interfere with shipping to Antwerp,
Rotterdam and Emden. What they have in mind is the shortening of the
coastline in the following three stages:
1. The closing of the Zuider Zee (which was done in 1932);
2. the closing of some Zeeland estuaries;
3. the closing of the Northern coast.
Since about 1935 the "second stage" has been studied. During these
18 years tidal calculations and an extensive research programme have
been carried out, while a large model was made of the area in quest
ion. By 1952 some 150 different schemes for this "second stage" had
been investigated. Another 100 or 150 possibilities had still to be studied
when on 2nd December, 1952, the Minister of Transport and Waterstaat
ordered the engineers to submit a report on whether it would be possible
and economically justified to close the Zeeland area between the river
Scheldt and the New Waterway. The engineers then got down to still
more serious planning.
As if it had heard the order, the sea itself answered two months later
with its angry assault. Never has a single flood caused so much damage,
never has it occurred that so many miles of dike gave way to the force
of the water and never before has the central part of the Netherlands with
its towns and cities been so near destruction.
The "third stage", namely the building of dikes to reclaim the Northern
tidal flats, had temporarely to be pushed into the background. Even the
„first stage", the reclamation of the Zuider Zee area, had to be largely
stopped. The first task which claimed full attention was to repair the
breached dikes, a task wich took the whole summer and all our skill.
It involved expenditure to the extent of a hundred million dollars. At the
same time the studies for the second stage had to be continued at tap
speed.
The Zuider Zee reclamation project has proved that the Netherlands
Waterstaat engineers are careful planners. Their mathematicians and
calculators predict the tides in the new estuarial systems with great
accuracy. Sand movements and salt penetration, as well as the economic
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