Abstract: An automatic shutoff valve for water conservation consists of a stoppage valve, a central flow tube, a floatation device, and a clamping mechanism. The central flow tube is rotatably positioned within a shell body of the stoppage valve. The floatation device which determines the orientation of the central flow tube. To do so, the floatation device is mechanically engaged to the central flow tube. Depending on the orientation of the central flow tube, the stoppage valve obtains an open configuration or a closed configuration. When used within a toilet tank, the open configuration allows water to pass through the stoppage valve. In the closed configuration, the water flow through the stoppage valve is discontinued. A first pair of stoppers and a second pair of stoppers ensure that the stoppage valve transitions between the open configuration and the closed configuration in a small operational angle.