Due to the land limitation, layout of an urban water pumping station is generally cramped and reflux, whirlpool and other undesirable flow patterns can easily be produced in the forebay of a pumping station. In order to improve flow patterns, an urban water pumping station that inlets water at the bottom of a water culvert was taken as an example. Numerical simulation of the flow patterns based on RNG k-ε turbulence model in the forebay of the pumping station was carried out and rectification measures for urban water pumping stations of the same type were proposed. It is found that large scale circumfluence exists on both sides of the forebay of the pumping station and the flow distribution of the suction sump is unbalanced, which can cause a bad inlet condition for the pumps. Rectification measures that combined with splay shaped diversion piers and sills can effectively disperse the dense central mainstream, eliminate the large scale wall shedding on both sides of the forebay and homogenize the inflow of the suction sump. These measures can help to improve the inlet conditions for the pumps and to increase the reliability of the pump station operation.