When we travelled to Europe last year, Tony and I flew to Amsterdam and then drove through the Netherlands and Germany into Denmark. We purposely chose a route that was interesting (to us) – our first priority being to see how the entrepid people of the Netherlands keep their country from being overrun by the ocean. About a fifth of the country’s land lies below sea level, so ingenuity is required.
In the picture below, you can see part of the North Sea called the Waddenzee on the right, and (just) the IJsselmeer on the left. The IJsselmeer is a shallow, man-made lake of fresh water, only 5-6 metres deep. The road shown is the A7/E22 on this map. It is a causeway called the Afsluitdijk, which is about 30 kilometres long, keeping the North Sea out and the IJsselmeer in (if the capitalisation of IJ annoys you, read this).
At each end of the causeway are discharge gates to allow freshwater to be released from the IJsselmeer, which has no other outlet and is continually fed by rivers including the Rhine. At low tide, the level of the lake is higher than that of the sea, so gravity can drain the water from behind the causeway. If sea levels rise, this won’t be the case any more.
I found an article on Wired.com from a few years back that explains how the Dutch are planning for the future -200 years ahead – by embarking on a $1.5 billion per year (for the next 100 years) project of strengthening, extending and constructing sea walls, sluices and other defences against rising sea levels. It’s a fascinating read about how a small (but wealthy) country is tackling its peculiar challenges head on, long before they arise. There are many lessons here (specially for climate-change denialists).
An interesting aside is that the Dutch political model, so-called polder politics, may have derived its name and nature from the need to protect the sea walls at all costs, leading to consensus-based politics that started with the crucial issue of protecting the polders (areas of land enclosed by dykes) and extended to broader issues too.
Read the full article here.
