The River Rother, a waterway in the northern midlands of England, gives its name to the town of Rotherham and to the Rother Valley parliamentary constituency. It rises in Pilsley in Derbyshire and flows in a generally northwards direction through the centre of Chesterfield, where it feeds the Chesterfield Canal, and on through the Rother Valley Country Park and several districts of Sheffield before joining the River Don at Rotherham in Yorkshire. Historically, it powered mills, mainly corn or flour mills, but most had ceased to operate by the early 20th century, and few of the mill buildings survive.
From the 1880s, the water quality deteriorated rapidly, as a result of coal mining and its associated communities. The river became unable to sustain life, and by 1974, was the most polluted of the rivers within the River Don catchment. The pollutants came from coking plants, from inefficient sewage treatment plants, and from the manufacture of chemicals. Major investment in upgrading the sewage treatment works took place, and in the treatment of industrial effluent before it was discharged to the river. The closure of the main coking plants has also aided the recovery of the river, and enabled restocking with fish to begin in 1994. By 1996, there was evidence for self-sustaining fish populations, and that the river could support organised angling.
