For the design of cost-effective coastal defence a
precise estimate is needed of the 1/10 000 per year storm surge.
A more precise estimate requires more observations. Therefore,
the three greatest storm surges that hit the northern part
of the Holland Coast in the 18th century are reconstructed.
The reconstructions are based on paintings, drawings, written
records and shell deposits that have recently appeared.
The storm-surge levels of these storms have been estimated
using numerical modelling of the coastal processes. Here we
show how these reconstructions can be used in combination
with extreme value statistics to give a more confident estimate
of low probability events.