We consider a 1-D tank containing an inviscid incompressible irrotational  fluid. The tank is subject to the control which consists of horizontal moves. We assume that the motion of the fluid is well-described by the  Saint-Venant equations (also called the shallow water equations). We prove the local controllability of this nonlinear control system around any steady state. As a corollary we get that one can move from any steady state to any other steady state. Full paper.