Abstract: A water flow-sensing device includes an assembly with a stationary metering rod with a cylindrical portion and a conical portion and a relatively moveable element in the shape of a hollow cylindrical toroid. The relatively moveable element is biased by a spring to a rest position wherein the cylindrical portion of the stationary metering rod blocks flow through the relatively moveable element. During fluid flow, fluid pressure moves the relatively moveable element so that the conical portion of the stationary metering rod is within the hollow portion of the relatively moveable element thereby creating a flow area and allowing flow therethrough. A toroidal ferrite is biased against the relatively moveable element and moves in unison therewith. The position of the toroidal ferrite is electromagnetically determined thereby allowing for a calculation of the fluid flow therethrough. Low flowrates indicative of a trickle leak and large flowrates indicative of a large leak can be detected.