For many generations, “Sturmflut” or “storm tide” was a dreaded word in Hamburg, Germany’s largest port. Though the city is 140 kilometers inland from the North Sea coast, the Elbe River is influenced by tides that far inland, and during certain conditions—typically high tide during a powerful winter storm, with the right strength of wind blowing inland—salt and fresh water mingle to quickly inundate harbor facilities and neighborhoods alike. Beginning in the Middle Ages the city’s history has been punctuated, every generation or two, with deadly storm tides, most recently in 1962. Since then Hamburgers have used the fruits of their city’s economic resurgence to build an elaborate network of levees and floodwalls—like the flashy 9-meter-high “Elbpromenade” in a popular area near downtown that was designed by the boutique Zaha Hadid architecture firm. Incorporating a parking garage and restaurant, its construction took nine years and cost 136 million euros. A local official calls it “perhaps the most beautiful climate change adaptation project in the world.” Just upstream, planners of the new HafenCity neighborhood redesigned an old wharf area with a different idea—let the streets and ground floors flood, but construct buildings to withstand occasional inundation. Dr. Olaf Müller, the city’s lead flood-protection engineer, describes what his job looks like in an era of climate change. Translated from the German and edited by Peter Friederici.

 

I studied civil engineering with an emphasis on water projects at several different universities. Afterwards I completed my state exam and completed a training at the federal transportation ministry. Hamburg’s agency for streets, bridges, and waterways was founded in 2007. I’ve been with it since the beginning.

 

Hamburg embodies a few different concepts for flood protection. It has 103 kilometers of levees. In other places we follow the wharf principle. And at the Fish Market we simply live with the water, as we let open areas and buildings alike get flooded sometimes. To date we haven’t had to pull back from the river due to flood risks.

 

The storm tide in 1962 cost 315 Hamburg residents their lives and will never be forgotten. It’s been more than 50 years since that catastrophe, but every year there are still memorial events on the 16th and 17th of February. Since then protection from storm tides has been a high priority politically, economically, and administratively. It’s become a community responsibility. The protective infrastructure has been continuously improved, and we’ve been able to ward off nine storm tide events that have been higher than the one in 1962. The levees have been raised about 2.5 meters.

 

All the buildings in HafenCity are built to a high standard of sustainability, and they stand as globally significant examples of innovative construction and contemporary community life. In 2013 HafenCity was recognized with, among others, the international ULI Global Award for Excellence. Many architects and planners from all over the world visit HafenCity each year. Coastal protection experts from across Europe are often there, because the entire development lies in front of the levees. It’s a wharf area with built-in protection against high water, so it’s also protected from the flooding that occurs during storm tides. The usual practice is to shield low-lying neighborhoods by surrounding them with levees. This principle, on the other hand, offers a lot of benefits and has attracted interest from engineers and planners from all over Europe.

 

Protection from storm tides is a continual task that spans generations, and it has to be accompanied by steady improvement in our understanding of the physics of storm tides. We have to measure a lot of parameters to understand how high it will be—for example, the effect of distant waves, damming caused by wind, or spring tides, or an accurate estimate of how much sea level will rise. Our calculations on how high we have to build have to provide protection in the future based on what happened in the past. Germany’s coastal states of Lower Saxony, Schleswig-Holstein, and Hamburg have agreed on a so-called “climate surcharge” of at least 50 centimeters by the end of this century. That means that a half meter gets added to the current high-water mark. Local tidal gauge measurements have already registered a rise of 25 centimeters in the last 100 years. And in the future we will be using satellite measurements to assess change over time. Storm tides don’t stop at political boundaries. We’re always consulting with the coastal protection experts in the neighboring countries.

 

Seventy percent of the costs for storm tide protection are carried by the federal government. The rest is the responsibility of the states. So it’s the citizens who are involved in paying for the effects of climate change through their taxes. So far this means of financing has worked. Hamburg is an international harbor city, closely tied to the water. That includes the reliability of our storm tide protections. Hamburg makes the needed resources available for raising levees and other flood protections. There’s no political debate about that.