17 januari 2013
'Thinking of Holland I see wide rivers winding slowly across endless plains,' wrote Hendrik Marsman in 1986 in one of the most famous lines of poetry in the Dutch language. The poem is called Memories of Holland. I wonder which scenes Marsman had in mind, as our major rivers were changed centuries ago using dykes and breakwaters to form deep fast-flowing shipping channels with narrow summer beds. What do you mean, wide?
In the nineteen eighties the 'Stork Plan' for the delta seemed to set new goals, but after the floods of 1993 and 1995, the priorities shifted from nature development to safety. River managers question the planned restoration of the original riparian vegetation. Drain water away as quick as you can, is the water board's motto, and trees and shrubs are quite a nuisance when you want to do that. But new hope is dawning. Recent research by Deltares shows that the creation of strips of willows along the rivers can increase safety from floods. These plantations slow the waves and reduce the pressure on the dykes. With this kind of 'green shield', an old-style dyke can still meet modern safety standards, I read in the Volkskrant. And to think that conventional dyke reinforcement costs three to five million euros per kilometre. The main solution, in my view, should be sought in increasing the capacity of the hinterland to function like a sponge and soak up excess water. But apart from that, it would be lovely if in future we saw wide rivers winding across endless plains.