Fighting Europe's rising water levels

By Timon Singh | 11/25/09 - 16:24

Can we stop rising water levels?

Everyone knows that if the ice caps and world's glaciers continue to melt, sea levels will rise. As such many European cities that are located on the coast are looking at upgrading or installing coastal defences, but what about those that lie several metres below sea level? In the next issue of EU Infrastructure, we will be looking at how Venice is dealing with rising water levels, but as a prelude, we look at how Rotterdam - Europe's busiest port city - is dealing with the threat.

Rotterdam lies several metres below sea level and its role as a port has seen it develop some of the best flood protection technology in the world. Water levels are expect to rise by half a metre by 2050 if climate change isn't halted, but the Netherlands has seen sea levels rise by 20cm in the last 100 years and as such, are taking no chances.

They have every reason to plan for the worse. In 1953, a massive storm surge caused mass flooding and killed almost 2,000 people. It was the spark that ignited a mass construction of defensive measures such as dykes, dams and even windmills. The massive 'Delta Works' network, that runs for several hundred kilometres, is said to be able to protect the country from "all but a one-in-10,000-year event."

However as Piet Dircke, professor of Urban Water Management at Rotterdam University pointed out to the BBC, "A one-in-10,000-year protection level sounds very good... but it's just statistics, and that event could happen tomorrow."

Stopping surges

Defences such as the Maeslant barrier are able to withstand a several-metre surge in water levels. With gates the length and twice the width of the Eiffel Tower, the 22m high barrier straddles the 300m Nieuwe Waterweg waterway designed to stop any surge that could flood the region. Whilst the Maeslant barrier was designed to close once every ten years, the rise in sea levels means the barrier will need to close more frequently in 50 years time, namely once every five years.

The Hurricane Katrine disaster was a wake-up call for the Dutch government and in recent years have continued to bolster marine defences, such as widening rivers and reinforcing the coastline with sand.

'Smart' concepts have also been suggested such as underground storage facilities for water, 'green roofs' to absorb high quantities of rainfall and 'water plazas', sunken areas in city centres that can be used as play areas but during storms can fill with water to relieve the sewers. With other schemes such as a 50-hectare (120-acre) floating housing development, Rotterdam is doing everything in its power to ensure its survival against the threat of water levels. Not just that, but it hopes that ideas and schemes implemented their can be used in developing countries under similar threat.