Record high waves, but Dutch dikes pass test

Nov 9, 2007, 10:09 GMT

Amsterdam - Ten-metre-high waves beat the North Sea coast of the Netherlands overnight, but damage caused by the storm remained limited.

The association of insurance companies VvV said on Friday the damage due to the storm was 'limited' and estimated it at no more than 500,000 euros (736,000 dollars).

The figure was small compared to the last three major storms in the past six years which caused some 480 million euros in damage, with the last major storm of January 2007 alone contributing 330 million euros.

The north-west storm that raced over the Netherlands overnight with wind speeds of more than 100 kilometres per hour caused record- high water levels.

The harbour of Vlieland, one of the northern islands in the North Sea, flooded Friday morning. Flooding also occurred in Terschelling and Ameland, two other islands in the North Sea.

Strong winds of 100kph are not exceptional for this time of the year in the Netherlands, but it is the combination of wind direction, rain and a seawater level that was already high prior to the storm that caused the state of alert.

In Harlingen, a town bordering on the north-east coast of the country, the seawater level rose to 3.4 metres above the so-called New Amsterdam Waterlevel (NAP), the standard used to establish the altitude of the water.

Near Rotterdam, the level stood at 2.84 metres above NAP while in Zeeland, in the south-west, the sea level rose to 3.43 metres, the third highest level since the Delta water defence system in the Zeeland province has been built.

Late Thursday night, all Dutch water defence systems along the North Sea coast, such as the Maeslant and Hartel defence systems near Rotterdam, had been automatically closed due to the high water level.

The coastguard patrolled the dikes from north to south during the night, but no major problems occurred.

The harbour of Rotterdam, which had closed down in the early evening of Thursday, also remained closed throughout the night and early Friday morning.

Elsewhere in the country, the first strong autumn storm of 2007 in the Netherlands caused damage to public and personal property.

In the province of Noord-Brabant, rooftops of homes were damaged and trees fell on cars.

In several places located near the sea, local flooding occurred. In Harlingen, the fishery storage and processing sites were all flooded, with water levels of up to 1 metre.

Later this morning, the water level in Delfzijl in the north is expected to rise to more than 4 metres above NAP.

The coastal guard along the whole north-east coast of the Netherlands will remain on high alert throughout the rest of Friday.

From the village of Petten in the province of Noord-Holland to the south however, the high alert has been lifted.

For Friday, rain and hail are expected to continue, again accompanied with north-eastern winds of up to 100kph.