This paper is devoted to the presentation and evaluation of different alternatives to couple two 1D hydraulic models based on the Saint-Venant’s equations. This presentation is first giving a short description of the coupling platform we use for these tests, namely the PALM coupling platform developed by Cerfacs. Then, we present 2 classical methods for this coupling: 1-way and 2-way. The 2-way method has itself different options depending on the variables exchanged at the coupling interface. Since we are using the implicit Preissmann scheme to solve numerically the Saint-Venant’s equations, we can imagine another option using the so-called RST equations. This method is not very intrusive into the source code since it does not require any additional calculation, and can improve a lot the results obtained by the 2 coupled models compared to the global one. This method can be implemented in an implicit way, being equivalent to the global model, or explicitly with some degradation of the results.