It totally depends on the river and specific local conditions.

It is complicated because of how kinetic energy can manifest.

You can have an increase in velocity, an increase in mass, or a combination of both.

The exact combination is dependent on a massive amount of variables like LWD, Manning roughness coefficient, channel longitudinal profile, channel cross-section geometry, amount of precipitation, amount of time precipitation occurs over, antecedent soil conditions (saturation excess vs infiltration excess flow), aquifer and other groundwater dynamics, hyporheic exchange rates… the list goes on and on.