The am compartments 'Speelmansplaten'
and /arollegat'in the Oesterdam
Furti er closure of the Oesterdam between the
lock sland and the Southern dam compartment
is to oe completed on the basis of two builder's
estir ates. The soil mechanical research which
is al\ ays performed before a design is made,
reve ed little stability in the build-up of the
four lation. In view of the safety factors to be
adhe ed to, both a soil improvement in one part
of th dike and a front load profile in another
part vere considered necessary. The work
proc esses from north to south, so that the final
closi re takes place just north of the Southern
dam compartment.
Dret jing of the Bathse Spuikanaal
The xcavations of the Bathse Spuikanaal are
carr; d out in two phases; banks, inlets and
mail enance roads are excavated on dry land
as a also some parts of the bridging and any
spot where bombs from the Second World
Wai are thought to lie. The rest is dredged
awa and brought over to four different spoil
depr ts.
Part if the dredging works was postponed, as
for e ample the digging out of the
Oos rschelde dike, as this can only be carried
out hen the compartment dams are
com ieted.
The redged soil is to be used partly for the spit
of la d on which the town of Bergen op Zoom
has ans to build a new district.
As t e auxiliary water will eventually lead into
the osterschelde, withdrawal is necessary
from tere as well.
The water quality in the future Volkerak and
Zoommeer
The Volkerak and Zoommeer to be formed
behind the compartment works will provide a
considerable extension to our lower rivers. The
incoming water is mainly form the Rhine and
the Maas and consequently contains high
concentrations of nutrients. By means of three
models bearing a wholly different framework it
was attempted to forecast the progress of algae
growth in a wet, in an average and in a dry
summer season, with a differing measurement
of flush helped along by the Bathse Spuikanaal.
The results of two of the models had much in
common. They give a reasonable, though rather
pessimistic estimate of the chlorophyll
concentration to be expected. The flush from
the Bathse Spuikanaal appears to be of little
influence.
Raising of the sea dikes along the North coast
of Groningen
The Groningen sea dike runs along the
Waddenzee, the Eems and the Dollard. In 1959
a first dam partition was reinforced to Delta
height. Since then 98 of the 101 km have been
reinforced.
Along the Wadden coast the actual defense
consists of three lines: the Wadden islands, the
mudflats and then the sea dike itself. It was
decided in 1967 not to polder in the marshes.
The construction height of the dike comes to
M.S.L. 8,85 m. The reinforcement is all on
the sea side and is made of sand obtained from
the Waddenzee, covered with concrete blocks,
water asphalt concrete and higher up with clay.
Because of poor accessability work began with
the building of access roads; after this auxiliary
dikes could be constructed between which the
dike was pumped.
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