The mining industry is moving towards thickened tailings with higher density than conventional operations. As  a  result,  tailings  transportation  is  more  challenging  due  to  the  material’s  tendency  to  exhibit non‐Newtonian behaviour at high solid concentration. One of the practical ways to transport tailings, where the terrain allows, is to gravitate the tailings through open channels from the thickening plant to the tailings disposal area. But in comparison to pipe flow, the flow of non‐Newtonian thickened tailings through open channels  has  not  received  sufficient  attention  in  the  literature.  This  paper  presents  a  set  of  models developed to predict the flow behaviour in the laminar transitional and turbulent regimes through open channels. The flow behaviour predictions of these semi‐theoretical models are discussed and validated against previously published experimental data.