A method of monitoring the movement of fluid through a fluid distribution network is described. The introduction of an additive to fluid is controlled at a control point in a fluid distribution network, and a concentration pulse in a concentration of the additive in the fluid is generated. Amounts of the additive are measured as a function of time using a plurality of sensor units located at identified locations in the fluid distribution network over a geographic area, wherein the sensor units communicate with one or more communication networks. Measurement data corresponding to measured amounts of the additive is received from the sensor units with a computer system, and the measurement data is processed with the computer system to generate information indicative of movement of fluid in the fluid distribution network. The information can be displayed on a geographic map of the fluid distribution networ