A fully developed turbulent open channel flow with a bed consisting of a space-periodic array of triangular elements has been numerically simulated. The solution procedure is based on the pressure-correction finite volume method with a collocated variable arrangement. Decoupling of the equations, inherent to the collocated variable arrangement, is avoided by using well-known Rhie and Chow interpolation technique. Reynolds stresses are approcimated usingk-ε and a full transport Reynolds-stress models of turbulence. Wall boundary condition takes into account wall roughness while the free surface is treated as a symmetry plane for all variables apart from the dissipation of turbulence kinetic energy. Comparisons between prediction and the measurements indicate that thek-ε model of turbulence is capable of predicting the main features of the flow to the acceptable level of accuracy.