Velocity will decrease.
That is, actually the water would have flown at this velocity, but it is flowing at this velocity. As if the additional water, additional velocity is a forward velocity. Do you understand? So, there is a drop in velocity due to wake, due to boundary layer. This is one effect boundary layer or this is called viscous or frictional wake. So, this is one reason for wake. The other reason comes straight from here that, there is a drop in velocity due to increase in pressure. So, this is pressure wake. Am I clear? Then there will be a third effect. That is what would happen