The kinetic energy and momentum correction coefficients are considered. After a review of pertinent literature, the discussion is restricted to uniform open channel flow. It is found both theoretically and experimentally that the coefficients depend significantly on the Manning roughness coefficient, and that the kinetic energy correction coefficient may directly be related to the momentum correction coefficient. Further, the effect of local variation of correction coefficients is much smaller than the variation of dynamic pressure times the correction coefficient. Therefore, the concept of constant coefficient as proposed earlier is justified. Key words: backwater curve, channel, distribution, flow, river.