At the time this happened in many natural disasters such as earthquakes, floods, tsunamis and others. Natural disasters occur with a frequency that is not stabilized, so many people who do not prepare themselves in the face of potential disaster. So many diverse tools or warning systems or disaster early warning system developed to anticipate the risk of disaster. One is the early warning system that is applied to the seawall. This system will provide sound an alarm when the flooding occurred in the river upstream, so that the sand or penambang population living didataran low can anticipate the risk of flooding. This system is perceived to be quite effective but less extensive coverage. Where alarmya only heard about one kilometer away, because the solution is the early warning system on floods based SMS Gateway in GNU / Linux can be an alternative in overcoming this problem. Moreover, this solution is applied easily and cheaply.