This research is about the design of flat coil-based pressure sensors to measure hydrostatic pressure of flood-prone water in the Lombok region of West Nusa Tenggara. The purpose of this study is 1) to make a signal processing circuit from a flat coil based pressure sensor, 2) to determine the amount of hydrostatic pressure at some depth of water in a flood-prone dam. This type of research is an experiment. The researchmethods include stages namely the design of flat coil sensor elements, distance calibration design, flat coil design, digital circuit design and data transmission. The measured variable is the flat coil vibration sensoroutput voltage. The distance of the metal to the flat coil will change after the sensor housing is immersed in water with depth h. The greater the depth of h, the more metal will approach the flat coil element. The flat coilsensor is measured in response to changes in distance from the metal, then the results are recorded and analyzed using linear regression analysis on Ms. Excel. Based on the results of data analysis, the results arein the form of Vout and PH equations, namely Vout = 0.000PH - 60.60. This equation is the final equation which states the linear relationship between Vout and PH. This means that if the depth is changed arbitrarily, at anytime it will be known also the value of the hydrostatic pressure which is indicated by the change in the output voltage on the sensor.