One-dimensional hydraulic models have the ability of solving the velocity fields needed by the well-known eco-hydraulic system PHABSIM (Physical Habitat Simulation System), in order to develop reliable functional relations between the discharge and a suitability index of the aquatic habitat. This paper presents a velocity simulation method that is complementary to the one integrated in PHABSIM, which we have called LogD (Logarthmic Distribution). It is applicable to a steady, uniform and hydraulically turbulent rough flow. This method uses the logarithmic velocity distribution of Prandtl-von Karman, depthaveraged and spatially extended to one cell. The simulations carried out on 135 representative cross sections of three basic habitat types (riffles, runs and pools) and on three different characteristic fluvial types (high-gradient, moderate-gradient and low-gradient) reveal an interesting predictive skills. The algorithm is calibrated using one horizontal velocity distribution shows a good performance when compared with current homologous method. The relative as well as the absolute simulation errors are smaller and less disperse when the solution scheme is calibrated with more than one velocity sets, although the accuracy-cost balance of the result obtained with one set is convenient.