3 / 36
DELTARES, FEBRUARY 2016
3
A
seepage screen has been
installed in the Perk Polder in
Zeeland to protect the fresh-
water lens in Kloosterzande.
It contains pipes that capture
salt water seeping underneath the dike.
Since June 2015, the salt water from the
Western Scheldt has been flowing in and
out of the new tidal nature area. That is
a concern for local farmers, who use the
groundwater from this area to irrigate
their fields. Aer years of exploratory re-
search by Deltares, extensive calculations,
the accumulation of specific information
about the groundwater system and six
months of intensive testing in practice,
the facility is working just as it should.
Indeed, the freshwater stocks are actually
growing naturally and so this would seem
to be a promising approach for small
islands throughout the world that will help
to prevent the negative consequences of
sea-level rise such as salinisation. Deltares
will be conducting further research.
For more information:
www.deltares.nl/en/projects/seepage-system-protects-
freshwater-lens-in-perk-
polder/
IMPROVING
THE FLOW OF THE
HIGHWOOD RIVER
A er the major floods caused
by the Highwood River in
June 2013, the province
of Alberta in Canada now
has to take steps to improve
its flood defences. Deltares
reviewed the sustainability,
cost-eectiveness and social
acceptance for two proposals,
and found some areas for
improvement. We advised
the authorities not to use
large-scale infrastructure but
to enhance the discharge
capacity of the Highwood
River. Our recommendations
mean that changes can now
be made to the river that
will be both safe and cost-
eective.
‘SCREEN’ TO STOP
SALTWATER
RESTORING
THE SEDIMENT
BALANCE
Some places in the
Netherlands are aected by
sediment shortages, while
others have too much. The
natural balance between
incoming and outgoing
sediment such as sand, clay
and gravel has been severely
disrupted. Both sediment
excesses and shortfalls have
dramatic consequences for
public safety, the economy
and ecology. This problem
is seen not only in the
Netherlands but throughout
the world. Deltares wants to
combine sediment supply
and demand with the aim of
exploring how to restore the
disturbed sediment balance.
DELTARES
IN BRIEF