The suitability of this approach was assessed for two
areas in Amsterdam, namely the Northern Banks of the
IJ and Westpoort. The location of the Northern Banks
of the IJ alongside this waterway makes the area vulneable to flooding from the River Lek or the North Sea.
The most important possibilities for limiting damage
are: elevating construction sites or building waterresilient
structures. However, bringing in soil from
elsewhere and raising the level of the land involves
a substantial outlay compared to the assets it would
protect and when set against the likelihood of a flood
actually occurring there. That is why the ‘multi-layer
safety approach’ is linked to other urban tasks, such as
district transformation, containment of flooding, nuisance
caused by urban heat islands and soil sanitation.
It turns out that a combination with, for example,
soil sanitation by way of increasing the elevation of the
land is indeed cost-effective: the areas with pollution
in the deep subsoil are raised by covering them with
a layer of clean, sanitised soil or with polluted soil
excavated from the area itself. The outcome is a varied
landscape of low-lying ‘wet’ zones with flood-resistant
buildings and residential areas that are elevated
and dry