Today was our tenth day in the Netherlands, and it began at 7. For breakfast I had a Latte, strawberry yogurt, sliced meat and cheese, a boiled egg, and pancakes. After breakfast, we boarded the bus to head to a storm surge barrier, which was built as part of the Delta Works. The barrier we visited was 3km long, and it consisted of 3 sections which were linked by 2 islands. This photo shows two of the three sections.
The Delta Works was a set of water management structures, and it began in 1956 after the disastrous flood in 1953. Check out my previous blog post on the Watersnoodmuseum to learn more about that flood. The Delta Works were built between 1956 and 1986, and in total they cost about 65 billion euros after considering inflation. The storm surge barrier we visited today accounted for more than half of that figure. As we approached the storm surge barrier, I saw an expansive wind farm near the North Sea. I found it interesting that these wind turbines were much larger than the ones we have seen farther from the coast. It would be interesting to know how they decide which size turbine to install in different areas.
It took about an hour to get from Rotterdam to the storm surge barrier. Once we arrived, we enjoyed some free coffee before learning about the Delta Works. The storm surge barrier we visited was built during the last 10 years of the Delta Works, from 1976 to 86. In early planning, the government aimed to completely seal off the channels. This idea would be like what happened in the Zuiderzee, which I have another blog post on. It would have completely disrupted the tidal environment and salt content of the water, which would kill a massive number of plants and animals. Once the public heard about this idea, many students, ecologists, and biologists demanded an alternative. While the government eventually listened, they had already started dumping rocks in the channels. Therefore, they had to use this massive claw to remove the rocks from the river.
Construction began by compacting the sand at the bottom of the channel, before laying out a massive plastic mat full of gravel and sand across the seabed. This mat was required to prevent the piers of the final structure from shifting, since they must stay in place for the gates to function. They then built 66 concrete piers (each 30-40 meters tall) in a pit 15 meters below sea level near the installation site. It took 4 years to build all of the piers, and they started building a new one every 2 weeks. Each individual pier took over a year to complete. They made 66 so they would have a backup in case one broke, and they never needed it. Each pier was 18,000 tons, but the boat to move them into position could only carry 10,000 tons. Therefore, once construction on the final pier was done, they flooded the pit and used buoyancy to help the boat move the piers into position.
The piers were placed during tide changes, since the current was low then. In the end, they were all placed within 5 centimeters of their intended positions. I found this to be extremely impressive, especially considering the size of the piers and the fact that they were placed in water. Once placed, each pier was filled with rocks. They then added the bridge elements at the top of the piers, and the doors. Each door was 200-400 tons, depending on its size. With that, the most expensive element of the Delta Works was completed.
The storm surge barrier has been used about 31 times in the 40 years it has been active, and the gates close when wind force, wind direction, and high-water levels create dangerous conditions. In normal times, the gates remain open to allow the tides to go in and out. I thought it was neat that they found a solution that works for people, plants, and animals. It usually does not impact wildlife, and when it is needed it can be set up in about 75 minutes to protect citizens from potential disasters like the 1953 flood. Dutch water management expertise has now been seen worldwide, where they have assisted with water management in New Orleans, Dubai, and more.
While I believe the structure is sustainable due to its low impact on wildlife and the protection it provides, I did hear some other opinions throughout the day. The storm surge barrier took a massive amount of concrete to construct, which has high greenhouse gas emissions. Additionally, it could be argued that spending so much money on a single structure is not economically sustainable. Furthermore, as sea levels rise, the lifespan of the storm surge barrier could be greatly reduced. This would then necessitate new solutions. Finally, it could be argued that reclaiming land from the sea with dredging is unsustainable, so the land should be returned to the sea and then it would not need protection.
While the overall sustainability of the storm surge barrier is debatable, I believe its construction was necessary. Suffering fatal, catastrophic floods is certainly not sustainable, so some type of solution was required, and I was impressed with their effective solution that has limited impacts on local plants and animals.
After visiting the storm surge barrier, we took the bus back to Rotterdam and got dinner at a local outdoor restaurant. I really enjoyed my day today, and I look forward to touring an urban garden tomorrow!
