Water diffusion device design in reservoir structures

In order to reduce urban runoff flowrates, reservoir structures are now used. Such use often implies the injection of rainwater coming from nearby buildings or catchments through these structures. This injection requires some diffusion devices to secure the homogeneous filling of the structure. This paper presents some useful instructions for the design of such devices. It provides information about diffused flowrates through a drain element according to the inside piezometric water head. It also deals with the hydraulic behaviour of a drain supplied with water from one end. A numerical model simulates this hydraulic behaviour. Lastly, a chart is provided in order to help water diffusion device designers.