Insufficient spillway capacity has been the cause of one-third of all dam failures. An innovative and effective way of increasing the spillway capacity is to use a Labyrinth weir in the modified form of PKW having range of specific flow from 3 to 1000m3/s/m. As the flow approaches towards the PK Weir, it was observed that the Z-component of the velocity of water in lower levels increases which enhances the flushing capacity. One of the important observations is that with decrease in discharge from higher flow to medium flow; Z component velocity is getting lowered by about 14 percent. Increase in discharge from lower to medium flow Z component velocity is getting increased by about 40 percent. It indicates that at lower discharge, upward velocity component is appreciably more which may be helpful for significant amount of sediment suspension at lower discharge also. For flood flow, it was found that there has been reduction of around 25-30% of submergence depth with respect to ogee spillway. Induced flow characteristics near PKW and tractive stress exertion by flowing water in the inlet cell are capable to flush out even the coarser sand particles. © 2014 by Taylor & Francis Group, LLC.