Historically, the Irk was also known as Iwrck or the Irke, names thought to have been derived from the Roebuck, suggesting that at one time it was a swift-running river.
In medieval times, there was a mill by the Irk at which the tenants of the manor ground their corn and its fisheries were controlled by the lord of the manor. In the 16th century, throwing carrion and other offensive matter into the Irk was forbidden. Water for Manchester was drawn from the river before the Industrial Revolution. A bridge over the Irk was recorded in 1381. The river was noted for destructive floods. In 1480, the burgesses of Manchester described the highway between Manchester and Collyhurst which "the water of Irk had worn out". In 1816, of seven bridges over the Irk, six were liable to be flooded after heavy rain but the seventh, the Ducie Bridge completed in 1814 was above flood levels.
According to The New Gazetteer of Lancashire (1830) the Irk had "more mill seats upon it than any other stream of its length in the Kingdom" and "the eels in this river were formerly remarkable for their fatness, which was attributed to the grease and oils expressed by the mills from the woollen cloths and mixed with the waters." However, by the start of the 20th century the Irk Valley between Crumpsall and Blackley had been left a neglected river, "not only the blackest but the most sluggish of all rivers".