This article describes the ongoing development of an observation and data collection system for seismic effects parameters at hydroelectric power plants. The field sensors and their placement are discussed in considerable detail, as are the means of communicating, processing, and storing the data from the sensors. An operating prototype has been developed and tested, with satisfactory resolution of basic problems. In the prototype, there are two eight-channel digital operating stations. Transducers of types A1632m and A1612 have been successfully tested. A check of the ADC measuring board confirmed the possibility of measurments in the 120-dB dynamic range. The data transfer system was tested with good performance, and the prototype is presently ready to take to the field.