The river provided power to some mills along its course. There was a water-powered corn mill at Dronfield, known as the Nether Mill or Lower Mill. It was recorded on a map compiled in 1710. A steam-powered flour mill was constructed a few years before 1813, and is thought to have supplemented the main corn mill. In 1845, the site included a kiln, a brewhouse, an engine house and machinery, a brazier's shop and a manufactory, in addition to the corn mill and its mill goit or tail race. The locations of other sites that used water power in Dronfield are marked by at least four dams, built in the 18th century to supply mills and workshops, as the river banks became industrialised to support the iron and coal industries. The uppermost of these was the iron foundry opened by Edward Lucas and Son in 1790. However, the industries were in decline by the time the railway arrived in 1870, and many houses became vacant when the steelworks relocated to Workington in 1881, taking large numbers of workers with them. There was a mill at Unstone, north of
Unstone railway station. The 1882 map clearly shows the mill pond, with buildings at its south-eastern end, but does not give any indication as to its use. By 1898 it was labelled Unstone Mills and was producing edge tools. It reverted to having no description in 1919, and by 1958 part of it was a "works" and other parts were in ruins. Further downstream, a mill at Unstone was recorded in 1538, when the miller was R. Seveyson. A later miller, Joseph Haslehurst, became bankrupt in 1826. The mill was called Unstone Mill on the 1840 Ordnance Survey map, but another map by Burdett called it Highwood Mill. In 1880 the mill was rebuilt, but did not last long as it was destroyed by a fire in November 1887. The site can be identified by the river channels, but there are few structural remains of the buildings, although small sections of wall were still visible in 1980. Ordnance Survey maps showed it as a corn mill in 1882 and 1898, but it was no longer in use by 1919. Another site was Coal Aston corn mill, close to the Chesterfield Road on the River Drone. The industrialist Christopher Rotherham moved there in 1820, and the site included his house, a grinding mill, a dam and a workshop. It was on the Hallowes Farm estate, and he developed it significantly, for by 1851 it was a sickle works employing 20 men, several of whom were related to him. There was industrial unrest at the works in 1856, when Mark Barker was caught after stealing 12 hammers and 20 pairs of tongs. At the trial, Rotherham maintained that Barker had stolen them because of his own anti-Union sentiment, and the stealing of tools was a common tactic at the time. This was never proved, but Barker served 18 months in prison with hard labour as a result. Subsequently, bellows were damaged, straps cut, and anvils thrown into the mill pool. Before 1860, his workers had refused to pay subscriptions to the Sickle Grinder's Union, and threats were made against him that the works would be blown up. There were several incidents involving explosives between then and 1863, when in June an attempt to blow up his warehouse, which was attached to the house where five members of his family lived, failed to detonate. He had had enough, and reluctantly persuaded his workers to join the Sickle Grinder's Union, after which the incidents ceased. After his death on 4 December 1870, the manufacturing of sickles was handled by two of his grandsons, who opened new premises at Unstone Mill in 1873, but the business failed less than a year later. It was sold to John Henry Harrison, Rotherham's son-in-law, and continued to produce sickles until it failed in 1953. On the River Whitting section, Whittington Mill was inferred in a deed dating from 1599, and near the weir a broken millstone carrying the date 1679 was found. The mill and kiln buildings were dismantled in 1735 and had been rebuilt by 1736. The work, for which detailed records are held in Chesterfield Borough Library, was commissioned by the Duke of Devonshire and cost £195-12s-8d. Two waterwheels were fitted, but the accounts do not mention any new millstones, although there were five sets. It was marked as a flour mill in 1876 and a corn mill in 1898. In 1886 the Elliot family, who were running the mill, took legal action against the Chesterfield Rural Sanitary Authority, alleging that they were in breach of their authorising
Act of Parliament. They were extracting water from the Barlow Brook, but had a duty to maintain some flow on the brook, to power Whittington Mill. The judge found in their favour, and ruled that water could only be extracted when the flow of the brook exceeded per minute. The production of flour is thought to have stopped around 1900, and the milling of animal feed in the early 1920s. The Elliots then used the building as a joinery workshop. In 1962, it was noted that the building had four storeys, but only one wheel, and although it had been unused for some time, all the equipment and the miller's tools were still there. In 2000 the building only had three storeys, with a slate roof, and the long thin mill pond alongside the railway had been filled in. A garden centre and car park have since been built over the site of the mill pond, although the mill building still stands in the grounds. ==Water quality==