This paper deals with the regulation problem of a class of irrigation canals using the Saint-Venant partial differential equations (pde). The Internal Model Boundary Control (IMBC) approach is used and the multireaches case is considered (several reaches in cascade). Perturbation theory of exponential semigroup used for control synthesis is extended here to nonhomogeneous hyperbolic systems, as the multireaches regulation model is described by hyperbolic pde's.Experimental results (on the Valence experimental canal) are encouraging for an extension to the real case. Additionally, a multi-model approach was introduced to allow wider water level variations.