Automation system comprising: a control unit comprising a microprocessor and several communication modules; a remote server connected with the control unit, a wireless sensor network connected with the control unit and comprising, at least, two flood sensor nodes placed on a floor or a wall and arranged to detect the accumulation of a liquid on a surface; wherein each flood sensor node comprises: a battery; a radio frequency module configured for enabling a wireless communication with a further flood sensor node and an external data network via TCP/IP protocol or data mobile network; a buzzer arranged to warn a user about water presence; a tamper arranged to detect the opening of the flood sensor node for handling purposes or sabotage; a tilt sensor arranged to identify a water stream and to know if the flood sensor node has been relocated or manipulated; and a measuring circuit arranged to detect the presence of two levels of water by means of at least two electrodes placed on the bottom of the flood sensor node and arranged to touch a flat contact surface; a microcontroller comprising a program or programs stored in a memory and configured for being run by means of the microcontroller, wherein said programs comprise instructions for: (a) measuring the impedance of a liquid in contact with the electrodes; and (b) sending the measured impedance to the remote server through the control unit; and wherein the remote server is arranged to receive the impedance of the fluid detected by the flood sensor and to estimate the nature of the liquid based on the measured impedance and the geographical localization of the flood sensor. a control unit comprising a microprocessor and several communication modules; a remote server connected with the control unit, a wireless sensor network connected with the control unit and comprising, at least, two flood sensor nodes placed on a floor or a wall and arranged to detect the accumulation of a liquid on a surface; wherein each flood sensor node comprises: a battery; a radio frequency module configured for enabling a wireless communication with a further flood sensor node and an external data network via TCP/IP protocol or data mobile network; a buzzer arranged to warn a user about water presence; a tamper arranged to detect the opening of the flood sensor node for handling purposes or sabotage; a tilt sensor arranged to identify a water stream and to know if the flood sensor node has been relocated or manipulated; and a measuring circuit arranged to detect the presence of two levels of water by means of at least two electrodes placed on the bottom of the flood sensor node and arranged to touch a flat contact surface; a microcontroller comprising a program or programs stored in a memory and configured for being run by means of the microcontroller, wherein said programs comprise instructions for: (a) measuring the impedance of a liquid in contact with the electrodes; and (b) sending the measured impedance to the remote server through the control unit; a battery; a radio frequency module configured for enabling a wireless communication with a further flood sensor node and an external data network via TCP/IP protocol or data mobile network; a buzzer arranged to warn a user about water presence; a tamper arranged to detect the opening of the flood sensor node for handling purposes or sabotage; a tilt sensor arranged to identify a water stream and to know if the flood sensor node has been relocated or manipulated; and a measuring circuit arranged to detect the presence of two levels of water by means of at least two electrodes placed on the bottom of the flood sensor node and arranged to touch a flat contact surface; a microcontroller comprising a program or programs stored in a memory and configured for being run by means of the microcontroller, wherein said programs comprise instructions for: (a) measuring the impedance of a liquid in contact with the electrodes; and (b) sending the measured impedance to the remote server through the control unit; (a) measuring the impedance of a liquid in contact with the electrodes; and (b) sending the measured impedance to the remote server through the control unit;