Ad Kil, who with Ro Koster makes up Ro&Ad Architects, was kind enough to send some information on how the the Moses Bridge (the bridge that cuts through a moat in the Netherlands) works and was built.
According to the designers, virtually no water spills over the edge because the height of the water is controlled by two small adjustable 'dams' at both sides of the moat. The dams are set at a height to ensure that when the water level rises, the water spills over and into the dams and not into the bridge. In case of a heavy rainstorm, a small pump under the bottom of the bridge evacuates the water.
The Moses Bridge was built in about 2 months in the middle of the moat waters by first dredging around the bridge site and then driving sheet piles into the ground, as shown in the photos below.
The 50 square meter (538 square foot) bridge cost 250,000 euros (330,325 USD) to build.
Ro&Ad Architects' work includes retail, residential, and cultural architecture and landscape projects that focus on sustainable design practices. Most of their projects, regardless of scale, are based on principles of city planning.
Images: courtesy and copyright of Ro&Ad Architects