January 23, 2007
Tuesday, January 23, 2007By Nate Wybenga
Our excursion today was a brand new one for the course. We traveled throughout Holland and observed the methods that have been implemented to protect against flooding in the rivers that are very important to the country.
In the morning we followed the Rhine River. The Rhine was a key location for battle during the war, and we observed several German fortifications as we traveled along the dike. The first method of flood protection we looked at was 3 ‘visor’ dams. The visor dams are semi-circular barricades that are able to rotate in and out of the water When they are not needed to protect against flooding, they can be rotated out of the water and boats can pass under them (see the picture below). The 3 dams in series provide protection against flooding for a large portion of water.
Next we took a little side trip and stopped in a town called “Wijk bij Duurstede”. The town is one of the oldest in the Netherlands, and was originally settled by the Romans! We took a walk around the quaint town, and even had the chance to stop by and look around a castle located there.
After our side trip we drove through what may be the highest land in the Netherlands, at about 100 meters high. The “Veluwe” (the name of this area) primarily consists of manmade forests, and is home to a lot of Army training facilities. The land is home for much wildlife, and interestingly enough the country has created wildlife overpasses for which the animals can cross over the highways that run through the Veluwe.
Next we drove into an area where a channel has been constructed to allow water that would normally flood the IJssel River valley to flood this specially chosen region. This manmade area amounts to essentially a lake that is connected to the river with its water height controlled. The “lake”, then, can hold extra water when the river floods and help keep the land dry. We received a tour of this area from a man who would be considered, where we live, a DNR ranger. He did not speak very good English, so Professor Aay had to translate for him, but we still learned a lot about that region.
Our final stop for the day was a town called Kampen. The town of Kampen has designed a unique system of protection against the flooding of the IJssel River. Instead of having a permanent dike system that would ruin the look of the historic downtown, the town had created a barrier system that can be assembled and put in place to prevent flooding. This was really interesting. The town has 200 volunteers who are trained to put up the dike. When a storm is coming, the water board calls these volunteers and assembles a group of 100 people that can put the protection in place. Over the course of 3 hours or so, walls are assembled all across the city, attached to brackets already in place or raised from their rest position in the ground, and then the city is protected against flooding! It was truly unique to see how all throughout the city there are brackets and underground walls that can then accommodate for protection against flooding.
After this we drove home and relaxed for the rest of the evening!
One of the ‘visor’ dams (in the up position)
The castle in the town Wijk bij Duurstede
Professor Aay translates for us
The water is transported from the IJssel to the storage channel
via underground tubing that creates a vortex in the water