Germany and the Netherlands Tackle the Risk of Rising Water

In today’s world, we need innovative solutions to help us anticipate complex demands across the globe. Water is strongly linked to global socioeconomic development, ranging from basic water safety, water quality and sanitation, to food supply and generation of renewable energy. The interwoven nature of these issues presents us with an ongoing challenge: to create feasible, smart and sustainable water solutions.

For centuries, Hamburg, Germany, and Rotterdam, Netherlands, have subsisted under the threat of rising sea levels, storm surges and floods. Now, as the water continues to rise, German and Dutch planners and engineers are forced to discover innovative ways to make these cities more resilient. They are experimenting with new ideas that fortify coastlines at lower environmental costs and learning valuable lessons that can be applied to vulnerable urban areas around the world.

Residents of these two great port cities have battled water since settlers first arrived centuries ago. Over the years, floods have destroyed property and, at times, drowned hundreds of people. Out of their ruins, these vulnerable cities have learned how to cope with the ever-present risk of flooding, and emerged as leaders in flood-control strategies and expertise.

Hamburg: Flood prevention innovation

Hamburg hosts Germany’s largest port, and is named the country’s “Gateway to the World." Europe’s second largest port, Hamburger Hafen, sits in an inland delta of the Elbe River, 110 kilometers (around 62 miles) from the North Sea.

When a very strong wind from the North Sea pitched a tide almost 18 feet higher than normal on Nov. 9, 2007, it sent a surge of water that rushed all the way to Hamburg, 56 miles inland. The port closed and a torrent washed through low-lying areas, wreaking havoc on homes and local businesses. However, one neighborhood, HafenCity, stayed nice and dry due to an innovative flood prevention program.

About 20 years ago, city officials realized that the islands, which were then an industrial district near the city center, could be put to better use. But before the idea could be realized, storm tides flooded the islands. Instead of ringing their 6 miles of shoreline with dikes to hold back the water, planners created a special development zone.

They demolished the old buildings and built new ones, with a new set of flood-related rules. The city built roads and open public spaces 25 feet above normal high-tide and waterproofed all of the structures. From being a city on the easternmost edge of the Western World, it has become the metropolitan heart of a continent growing together again, and a place with enormous potential.

By elevating the buildings on plinths made of mounds of compacted fill (warften in German), it has been possible to connect HafenCity with the existing city area and develop it step-by-step from west to east, and from north to south. All new buildings stand on artificial bases well above sea level -- out of reach of the most extreme flooding.

Rotterdam: Beyond barriers

As with Hamburg, a catastrophic flood also reshaped Rotterdam. On Jan. 31, 1953, a powerful storm struck the Netherlands, swamping nearly 340,000 acres of land and killing 1,800 people. This disaster compelled the Dutch government to design Delta Works, an initiative designed to protect areas that flood regularly from rising water.

In addition to reinforcing thousands of miles of dikes lining flood-prone rivers, this plan called for building robust dike-rings around large territories encircling Rotterdam, Amsterdam, and other urban areas, damming the bays with huge flood gates.

When a storm surge reaches 9.8 feet above normal sea level, two massive doors swing on pivots from opposite shores, meeting mid-stream like hands clasping. The Maeslant Barrier, a movable gate at the mouth of the Rhine River, is among the largest moving objects on Earth, each door being 787 feet long and weighing 15 million pounds.

As impressive as it sounds, this colossal flood gate did not come without a cost to the environment. It has been said to have caused serious ecological damage to the coast. “The technological approach has not brought us a sustainable solution,” explained Jan Mulder, a coastal engineer for a big Dutch water consulting firm, Deltares.

The barrier completely cut off three branches of a large estuary from the sea, transforming them into artificial freshwater lakes. It has seriously degraded nearby wetlands, algal blooms have plagued the water bodies and the fish, shellfish, and marsh grass that lived there have also disappeared.

The future of coastal cities

In the coming years, many more cities will take up the struggle that has preoccupied Hamburg and Rotterdam for more than 1,000 years. Last year, the U.S. Department of Housing and Urban Development revealed six plans for protecting the New Jersey and New York shores from storms like Hurricane Sandy, and allocated $2.5 billion in initial funding. Five of the funded projects — which included the use of dikes, rejuvenated marshes to slow storm surges, and natural basins for temporary storage of storm waters — were submitted by groups that included Dutch engineering and design firms.

While Germany, the Netherlands, the United States and other industrialized nations have the means to confront, if not overcome, rising sea levels, countries in the developing world — from Cairo to Bangladesh — generally do not. And one of the most important discussions taking place at the United Nations climate talks in Paris will be exactly how much aid industrialized nations will provide poorer countries in their battle to tackle rising sea levels.

However, despite the number of exciting innovations in this area, some people believe that a coastal retreat is inevitable. “Fighting water is a war you never win,” argued Henk Ovink, special envoy for international water affairs for the Netherlands. This is especially true today considering that global sea levels are projected to rise at least three feet this century. “Societies all over,” Ovink continued, “have to rethink."

Image credits: 1) Flickr/Giorgio Tomassetti; 2) Flickr/Thomas Wensing; 3) Flickr/Moyan Brenn