The Veluwemeer Aqueduct: Netherland's Unique Water Bridge
Opened in 2002, the Veluwemeer Aqueduct is a stunning work of architecture and engineering. Unlike other solutions for allowing vehicular traffic and waterborne traffic to pass over or under one another, engineers decided on a different approach: a water bridge.
Located over the N302 road, the aqueduct forms part of a lake of the same name. The road itself is interesting in and of itself, connecting mainland Netherlands to Flevoland — the largest artificial island in the world.
Flevoland was constructed from reclaimed land in the region and is surrounded by three man-made lakes. This island is actually made up of two drained sections, Flevopolder and Noordoostpolder, which come together to make up the 374.5 square miles (970 square kilometers) province of Flevoland.
During the design of the unique bridge structure, engineers chose to construct the waterway over the N302 road, where around 28,000 vehicles pass each day.
How does the Veluwemeer Aqueduct water bridge work?
The Veluwemeer Aqueduct is a shallow 9.83 feet (3 m) deep water bridge that allows for small boats and other shallow-draft water vehicles to pass over the road safely and easily.
In addition to allowing boats passage over the road, pedestrian walkways can be found on both sides, allowing for foot traffic to also cross. The road itself also includes designated cycle lanes.
Unlike drawbridges or other roadway structures, the water bridge design allows for constant traffic flow both on the road and over the aqueduct.
For most of the span of the N302 road across the lake, the road is raised above the waterline by a stretch of artificial embankments, but for the short, 55.7 feet (17 m) span on the aqueduct, the road plunges, briefly, underneath the lake's surface.
Interestingly, around 1,3212 feet (400 m) NW of the aqueduct, the N302 crosses the lake once again on a more traditional bridge structure.
Veluwemeer Lake (ps. "meer" is actually Dutch for lake) is one of fourteen 'bordering lakes' in the area, all of which are really just a very long continuous body of water, that was created by not completely connecting Flevoland and the Northeast Polder to the mainland of Netherlands.
The lake system was originally constructed to help regulate water levels and the groundwater table in the surrounding areas. Now established, the lakes are also important nature reserves (especially for water birds) and recreational areas for local residents.
The Veluwemeer Aqueduct was built using 776,922 cubic ft (22,000 cubic m) of concrete, and steel sheet piling to both hold the weight of the water above the roadway and prevent sediment from bleeding onto the road.
Why was the Veluwemeer Aqueduct built?
During the planning phase for the project, drawbridges, ferries, and tunnels were considered as likely solutions to allowing the road to fully cross the lake. However, these were decided against, and the novel approach of building a short aqueduct over the road was selected.
Because the N302 is a major highway, it was deemed unrealistic, and inefficient, to stop the flow of traffic using a drawbridge or ferry solution. A tunnel, an option also likely considered, would have required too much time and expense when compared to the aqueduct solution finally settled upon.
A bridge, while a more typical solution to the problem, was deemed to be far too costly compared to the more reasonable cost of the aqueduct solution, at around $61 million. Given that the point at which it was to be built did not need to carry wide water traffic, its narrow aqueduct design was also deemed to be a wise choice.
While this structure does not set any records, it does stand as one of the shortest aqueducts in the world. Not to mention, one of the world's most interesting.
If you ever find yourself in the local area, it might just be worth taking the time to check it out for yourself.