which is tapped from the mains net, and a
peak capacity which is only necessary when
all the gates have to be set in motion at the
same time. In this case the necessary energy
is generated in two private power stations,
each with five aggregates of 725 kVA.
Protection of the soil during the building and
termination phases
The Oosterschelde soil protection extends on
both sides of the barrier over about half a
kilometer. It consists partly of asphalt mastic,
partly of stone asphalt mats and partly of
block mats.
A large part of the soil protection had already
been laid when the decision was taken to
build a storm surge barrier in the Oosterschelde
instead of a closed dam. This considerably
increased the demands made upon the
design. It was apparent from model research
that the covering of the soil protection with
rubble would have to be considerably extended
locally. Subsequently a survey was done on
the current patterns which would occur
- while the storm surge barrier was being
completed - with the various possible
positions of the gates. Two favourable
configurations emerged: position of the gates
successively opened and closed, or otherwise
all the gates partly closed.
The dredging of the ring dikes around the
Krammer locks
In order to be able to place the sliding doors
in the Krammer locks the ring dikes had to be
dredged. First the westerly ring dike was
dismantled and the construction pit was
inundated up to M.S.L. 2 m., so that the
water flowed out when the dike was dredged.
The doors were placed during the construction
workers holiday and then the dike was cleared
on the east side of the locks.
The Slaak compartment dam was made with
sand thus made available. The spouting of this
dam met with some difficulties: the capacity
of the dredge was insufficient to close off a
gully through the mud flats which crossed the
tracing. The job was completed in the end
however.
Ground water levels in the areas around the
Krammer, Volkerak and Zoommeer
Ground water levels may change in the areas
behind the compartment dams, when tides
cease there in the near future. Research has
been set up into this problem, based on
332
periodic measurings in gauge pits construe ed
for this purpose. A measuring report appea s
yearly.
Besides this a commission has been set up to
decide in how far the Delta Works are
answerable for damage claims.
In particulair it had to be decided what
influence the changes in the ground water
level have on harvest produce in agriculturfIt
turns out that possible damage which may
occur will be very little.
Technical support of environmental reset ch
In order to carry out the extremely extensive
qualitative and quantitative environmental
research in the Delta waters the Main
Department of Environment and Lay-out et n
call upon a Technical Support Department in
which all necessary disciplines are brought
together and where technical innovations re
constantly being worked on.
Within this Technical Support Department jve
may distinguish between the following
groups: a group Field Services - subdivide
according to water areas and intertidal are is,
a group of measuring systems, a number c f
chemical laboratoria, and a service group tor
the processing, storage and presentation cf
measuring data.
