Abstract: A water relief valve for a drainage system includes a hollow cylinder body and a poppet valve which is inserted into the top of the cylinder body. The pair is connected to the top of a buried pipe section and is flush with the ground after installation. The pipe section connects the downspout of a gutter system to the valve which is positioned away from the building. During rainfall the runoff water passes through the underground pipe until it reaches the valve and forces the valve open and the water discharges around the valve and away from the structure. In this way the runoff water can be dispersed to the grass area away from the house. When not in use, the valve lies flush with the grass and is unobtrusive. The water relief valve also has applications for drainage of large playing fields, farm acreage, and paved areas such as parking lots.