Nowadays dams start to use labyrinth weirs to replace structures due to the fact that the original structures are insufficient. As a consequence, the volume of discharge in a situation of high event increases the body's normal level of water to replace losses of dam volume while maintaining the same level of high water. These losses happen because of sedimentation. The hydrodynamic device influences the increase of the discharge, and it is well known that as more water is placed above this structure, far from the effects of the channel walls, the coefficient increases. The numerical specification (discharge coefficient) of their operation is important to implement in any design or rehabilitation. Using Labyrinth weirs are an increasing practice in spillways reservoirs, needed to raise the level of normal water, keeping the same free edge of prey, which is very important when do not have an adequate volume for flood control. The main focus is test two devices design, considering constructive requirements. Previous some hydrodynamic forms design was testing, but others in side requirements consider new designs.