A detailed measurement campaign is performed in which the development of and the effects on a velocity profile in the suction pipe of a vertically submersible pump is investigated. The measurements are performed in a scale model of a simple pumping station of which the dimensions are based on the ANSI/HI 9.8-2012 guidelines. It was observed that the spatial deviation decreases significantly with a small increase in the measurement height. Apart from generally accepted modifications such as splitters, fillings, curtain walls and baffles, modifications to the main dimensions (such as bottom clearance, water level and discharge) have been tested as well. The investigation showed that the acceptability as defined in the HIS standard (HIS 2012) of a velocity profile is not significantly influenced by these modifications (if well-designed). Some modifications have a local effect on the velocity profile only, while the positions with the largest spatial deviation, which determine the acceptability of the spatial velocity profile, are not affected.