Sensors installed in rivers to detect rising water levels stopped working because of the sheer amount of water, the head of the Environment Agency has admitted.
The torrential rain is contributing to record-high river levels and England has endured more than double its average February rainfall so far.
Sir James Bevan told The Telegraph the floods "destroyed some of our assets", including the equipment that logs river height.
Speaking at the World Water Tech Innovation Summit in London, he said: "One EA team was anxiously watching the telemetry data from one particular river which was showing an astonishingly rapid rise when the water levels suddenly appeared to stop going up.
"The team breathed a sigh of relief until they realised that the graph wasn’t flatlining because the river had stopped rising. It was flatlining because the river had risen above the electrics running the gauge and overwhelmed the hardware."
He said the sensors will have to be replaced once lives and property have been protected from the floods.