hello , i’m a beginner in Hec ras i tried to make an unsteady simulation of a river , in the boundary condition i put a hydrograph (Q=f(t)) which increase then decrease totally with only one pic , and in the downstream i choose the normal depth type , the simulation success but the problem is when i chek the hydrograph resulted in downstream RS the flow don’t stop , and with high value , normally a hydrograph is like a wave moving through the channel , thanks for reading and more thanks for contributions