In November 2016 Aqua Vision carried out current measurements in the river Waal near the city of Tiel. In the past years, Rijkswaterstaat has replaced several river groynes in this section of the Waal. These new groynes are constructed laterally, in the direction of the main channel, instead of perpendicular to the river. The groynes are several kilometers long and have small gaps in them roughly 200 meters wide. Rijkswaterstaat is interested in how much water flows through these gaps in different circumstances, so Aqua Vision was contracted to measure these discharges.