The MOCHA project at CEMRACS 2016 (07-08/2016) is a collaboration between CERFACS, EDF (LNHE) and INRIA dedicated to multi-dimensionnal coupling in river hydrodynamics. This approach offers a convenient solution to complex flow modeling while limiting the computational cost and making the most of pre-existing models. A lateral interface coupling solution was implemented between a 1D model adapted to the main channel dynamics and local 2D models able to represent the flood.