The river's flow is measured at several points along its course, at a number of gauging stations. At Stoke-on-Trent in the upper reaches, the average flow is only , which increases considerably to , at Great Haywood, as it includes the flow of the upper tributaries draining the Potteries conurbation. At Yoxall, the flow increases to due to the input of larger tributaries including the Sow and Blithe. At Drakelow upstream of Burton the flow increases nearly three-fold to , due to the additional inflow from the largest tributary the Tame. At Colwick near Nottingham, the average flow rises to , due to the combined inputs of the other major tributaries namely the Dove, Derwent and Soar. The last point of measurement is North Muskham here the average flow is , a relatively small increase due to the input of the Devon, and other smaller Nottinghamshire tributaries.