Saturday, January 8, 2011

Bringing Back the Beach

Everything seemed normal in the North Holland beach town of Bergen aan Zee as we bathed in the sun and the sea late last August.  Of course the beach season was winding down soon after with school starting and temperatures dropping.  But it was a curious sight last November to see large metal pipes running parallel to the coast line above the sand.  And then in December when the metal pipes were gone, two ships were anchored just off shore spraying something high into the air.

The Dutch government decided in 1990 that the coastline should not move at all inland from its position at that time.  This beach is an essential barrier protecting  
populated areas and farmlands that could be at risk from flooding from the North Sea and its rising water levels.  Wind, waves and currents are perpetually assaulting the coastal barrier and the Dutch have not been hesitant to fight back against Mother Nature.

So the large pipes and spraying ships were part of an ambitious engineering project by the Rijkswaterstaat to replenish sand that has been washed away by currents and other natural forces.  The pipes were quite obviously in the way of some activities on the beach, but the ships just off-shore were interesting to watch.

I spoke by telephone with Pieter Zoon, a spokesman for the grand project.  He explained that the ships were depositing sand into the sea in places where the currents would naturally transport the sand onto the beach in places where it’s needed.  Mr. Zoon said this process is called the rainbow – due to the visible arc launching from the ships – and is the preferred method of beach replenishment.  Pumping the sand directly into the beach using the high-pressure pipes is more costly and the sand has to then be moved by bulldozers to the proper position.  The pressure pipe method is used in more urgent cases where more of the beach has been lost.  The sand is pumped in mixed with water, then the water is extracted leaving the new sand in place.

A document provided by Mr. Zoon stated that this sand replenishing project could also lead to new islands or coastal land being formed in some cases.  He said that 3 million cubic meters of sand is being relocated in just a 3 kilometer stretch of North Holland coastline between Bergen aan Zee and Egmond aan Zee.  I asked him if this was actually a discreet plan to expand the land mass of the Netherlands, but he assured me that the project’s aim was merely to maintain the coastline at its location as surveyed in 1990.  Perhaps it was not such an outrageous question given the country’s ambitious history and engineering prowess when it comes to moving land and water.

I also asked about this project’s effect on marine animals and their habitat.  Mr. Zoon said that studies had been done, but no further information was available.  An employee at the aquarium at Bergen an Zee said by telephone, “Of course every touch by humans disturbs the fish life, but the impact is not that dramatic.”  He said that there had been no major protests over the project’s effect on marine life, and that “when they put the sand on the beach, the birds gather and we presume there are crabs and other things moving around for them to eat.”  Imagine being a crab scurrying along the sea floor, and suddenly being sucked into a high pressure pipe and transported like an invading marine onto the beach just to be quickly eaten.  Anyone having information on the project and marine life is welcome to leave a comment.

And for more information on the reinforcement of the Dutch coastline, see the document “Because the Dutch love their coast.”  

1 comment:

  1. These beach restorations are always huge projects that always take a lot of money and resources to undertake. I admire the Dutch government for successfully pulling this up for the people to enjoy.