The velocity structure and turbulent characteristics of vegetated open channel flow were studied computationally using the computational fluid dynamics (CFD) code FLUENT to find logical distribution of vegetation in the flow to minimize flood disaster. A three-dimensional Reynolds stress turbulence model was first validated with the experimental data and then used for investigating properties of flow through vertically double-layered and discontinuous vegetation patches that occupy both sides of an open channel with different patch patterns— linear and staggered. Results indicate that the flow velocities within the gap zones are reduced by the sheltering effect of vegetation patches, which is observed to be significantly higher for the flow through staggered patch pattern than that through linear pattern. Flow velocities in non-vegetated main channel increased by 29 % and 36 % compared to that in vegetation sides of the channel—canopy and gap—for linear and staggered pattern, respectively. The findings indicate that the higher flow resistance on the channel’s vegetation sides in staggered pattern is balanced by the faster flow in the main channel, which could be utilized effectively during higher flows like floods over the floodplains. Moreover, velocity magnitude as well as fluctuations and turbulent kinetic energy (TKE) in vegetation sides are lower in flow through staggered pattern than that in linear pattern, which satisfies a better feature for aquatic life in staggered pattern. Thus, this arrangement of staggered vegetation patches can be used as an effective measure for flood mitigation as well as providing positive feedback for aquatic life and sediment deposition.