Understanding and characterizing the wake flow of a wall-mounted obstacle is important in various engineering applications, including pipeline transmission systems. Patterns of flow and flow-force of great complexity arise in a river once a bluff body is placed near the river bed, which remains a topic of immense importance in applied hydrodynamics. The present study aims to experimentally investigate the mean and turbulent flow characteristics downstream of a single wall-mounted horizontal cylinder. Experiments were conducted in a 21.3 m long, 0.75 m wide, and 0.74 m deep rectangular flume using two different flow scenarios (83.33 l/s, and 55.55 l/s). The pipe under investigation in this experiment was a horizontally mounted 0.11 m diameter cylinder fixed to both ends of the flume with an opening of 0.005 m from the bottom. A downward-facing three-beam acoustic Doppler velocimeter (ADV) was used to measure the 3D instantaneous velocity time-series data at each point with a sampling duration of 120 s. Measurement stations were positioned at different relative streamwise distances, along with variations in vertical locations, to capture the wake flow characteristics. Preliminary investigations with 0.005 m opening were made with velocity profiles and isocontours of dimensionless streamwise velocity. The lengths of the recirculation zones and their flow changes under the two flow scenarios were also studied. The magnitude of the turbulent kinetic energy profiles exhibited a trend with varying flow rates in the longitudinal direction. The results of this study are expected to provide a good understanding on the flow development and variation of turbulent kinetic energy, and thus will support a better understanding of flow fields downstream of wall-mounted horizontal cylindrical obstacles.