The linear Muskingum method continues to be a simple and popular procedure for river flood routing. An alternative algorithm for the numerical estimation of the Muskingum routing parameters is presented. Fully implicit and semi-implicit finite-difference schemes are compared for accuracy with respect to the traditional graphical procedure. A stability analysis and an objective criterion for the application of each scheme in the light of different measurement intervals for the inflow and outflow hydrographs is discussed. An application example and recommendations are included.