Flood Disasters are natural disasters that almost occur every rainy season in Manado City. Therefore,   a Communication System Of Early Warning Flood is needed as an effort to mitigate disasters, involving warning information services through monitoring activities involving various parties; dissemination of warnings that are easily understood by people facing disasters; and the ability to respond and act quickly when disasters occur. With the existence of  the Flood Hazard Early Warning Communication System, it is hoped that it can reduce casualties, property losses and psychological impacts can be avoided.

The results of the study show that the Early Warning Communication System for Flood Hazards as a Disaster Mitigation Effort in Manado City, starting from: Detection, which uses sensors that will predict the situation in a certain environment, as well as a remote dashboard to monitor the output of the sensor and display it in a clearer and easier to understand form. There is also a device with the ability to serve and routing, i.e. to detect specific conditions to take appropriate action. Forecasting, which is a forecast of rainfall, water level or flood discharge and the time of arrival of the flood, and is continued to give warnings. Warning and Dissemination, which is using information obtained from  the detection or forecasting stages that disseminate the information to be able to minimize the risks it causes. Response, namely: responsiveness to the issue of flood warning, and this is very important for the achievement of the goal of implementing flood early warning.

As a recommendation, the government and the people of Manado City must maintain the equipment used in    the Communication System Of Early Warning Flood in Manado City so that the equipment functions properly, and there must even be maintenance costs when there is a damaged device.

A quick response is also expected to be highly expected, so that when getting information that there will be a flood, the Manado City government changes the information into directions which are a follow-up to decisions taken in the form of a series of directions, both dynamic, namely SAR, Evaluation, Resource Mobilization, Warnings or Instructions for the community. It can also be in the form of static directives, namely waiting for further information, standing by, or not needing to take any action.

Keywords: Communication System, Early Warning of Flood Hazards, Disaster Mitigation