Systems, methods, and devices for performing real-time detecting and spatially-positioning a waterfront in an oil-producing reservoirs are disclosed. An example method of predicting movement of a waterfront in a reservoir may include generating a plurality of electrical signals having different frequencies with a surface electric source; injecting currents corresponding to the plurality of generated signals into the earth near a well extending into the reservoir with a surface dipole; sensing a vertical component of an electric field generated by each of the injected currents at a location in the reservoir with a sensor; detecting a location of the waterfront within the reservoir based on the received vertical components of the electric fields; and analyzing the detected vertical components of the electric fields taken on at least two different points in time with machine learning to predict a rate of movement of the waterfront within the reservoir.