This document aims to find a good approximate solution of the water profile that occurs in open canals with a spatially varied flow concerning an increasing discharge. An introduction to the Spatially Varied Flowand its applications in natural and artificial canals is presented and a detailed deduction of the governing equation is done. The equation that describes this flow condition is an Ordinary Differential Equation. A numerical code is then written in order to solve the ODE that defines the water profile. The location of the internal boundary condition stands as a key step for a successful computation and a systematically procedure to determine it is described. All physically possible locations and their associated implications are also discussed. All possible situations regarding the Increasing Spatially Varied Flow occurring in a two slope rectangular canal are studied and the impossible situations are briefly explained. In the cases wherea Hydraulic Jump occurs further computations are carried out in order to obtaina final water profile that fulfills both internal boundary conditions. Additionally, the water profile obtained in a street drainage canal is analyzed to understand the way it commonly fails.