The Bathse Spuisluis and the syphon under
the Spui canal
A fresh water basin will be formed at the back
of the Oosterschelde on the execution of the
compartment works. In order to maintain the
water level and the quality of the water in the
basin a drainage system will have to lead into
the open Westerschelde. A canal is being dug
for this purpose through Zuid-Beveland with a
discharging sluice at the end.
According to the definitive design this Bathse
sluice, situated in the Westerscheldedijk,
consists of six tunnels which are sufficient for a
discharge capacity of 100 m3/s. Discharge is
regulated by the number of tunnels opened.
The discharge characteristics of each tunnel
have been investigated in a model.
With normal use the gates are raised
hydraulically to a height of 5,85 m. Energy
provision comes from batteries topped up with
mains voltage. The discharge construction has
receding walls and a zig-zag sill. The deposit
bed is 100 m long, with decreasing stone
weight of the top layer. The tunnels are
operated automatically either on the spot or
from the Kreekrak locks.
Thesyphon is a waterway under the Spuikanaal.
The architectural part of both works was
completed in 1984.
Hydraulic works and underwater life
Underwater life on hard sub-stratas under
water has introduced a flora and fauna
previously unknown in the Netherlands and
which can therefore be considered as an
enrichment. Research has been carried out
since 1979 in the Oosterschelde and in the
Grevelingen. The vertical layering and the
relation to the type of sub-stratum have proved
especially interesting aspects. As far as the
layering is concerned an accurate inventory is
being set up in order to be able to make
forecasts which can later be tested with regard
to the influence of changing tides in the
Oosterschelde. It is not only the physical and
chemical characteristics of the sub-strata which
are the object of attention but also their form
and the texture of their surface. Experiments
were initiated on eleven sorts of stone.
Continuation of these experiments with
concrete blocks appears to be the most
promising.
Strengthening of the Flaauwe Werk sea
defence on Goeree
The last part of the strengthening and
raising of the primary sea defence on
Goeree, between pillars 11 and 13, is being
carried out in the form of a dike with an
asphalt covering. However it connects up
on both sides to a coastal range of dunes. A
clay dike had already been built along this
stretch in the eighteenth century. A further
strengthening of this coastal defence is
being carried out this year as a continuation
of the initial restoration afterthe catastrophe
in February, 1953. There has been extensive
discussion on aspects of landscape with the
authorities concerned and with nature
preservation societies before deciding on a
design.
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