This paper presents the development of a low rate and low power consumption wireless sensor network. Wireless sensor networks are cheap and comprised of a small fully autonomous processing communication and sensing devices. The purpose of this study is to develop the system for monitoring and flood warning. They will work with wireless sensor network (WSN) system. WSN has been restricted power supply communication distance and low computing power. But they will work with network in vast area send and receive raw data from each sensor node. It has the ability to cooperatively collect data and retransmit in order to process or alert. The first step of the experiment is creating main node and sub node in flooding area and finds transmission of data between them. When sensor node is not receiving or transmitting data the module can be switched into the sleep mode low power consumption mode