Rainfall runoff phenomena in small watersheds are favorably modelled using the kinematic wave approach. The present investigation considers excess rainfall as time dependent but ignores spatial effects. Solutions of a recent approach are analyzed for a complete cascade consisting of catchment area and small stream. Typical cases are discussed and results include predictions of maximum discharge at the watershed outlet, corresponding time to peak and the overall description of the resulting hydrograph. Criteria concerning the applicability of the kinematic wave approach are given, and examples illustrate the computational procedure.