Sub-surface drainage peak flow rates are in general smoothed at the plot scale because of an increase of local infiltration capacity and a reduction of surface runoff, whereas transfers are accelerated by the arterial drainage system, which is often over designed due to the depth of the collector drains. This flow acceleration can be reduced by letting the network overflow in its less critical zones. This solution, which can result from adequate reduced cross sections such as crossovers for roads, is referred to as dynamic flood control. But very few methods are available to correctly define how to obtain these overflows and to afford maintenance problems. In order to describe the peakflow transfer through a small agricultural catchment, an hydraulic model based on St-Venant equations was used, and applied to an experimental catchment near Paris (Orgeval, Seine-et-Marne), in which runoff comes essentially from subsurface drainage. The experiment and model results are used to build recommendations on dynamic flood control at a small catchment scale, by means of a correctly designed surface network, especially its reduced cross sections. These recommendations are now to be validated by multi-scale experiments, and design of effective equipment.