[3] The source of the river is at Pilsley near Clay Cross in Derbyshire, from where it flows to the west for a short distance, before turning to the north.

The valley is shared with the Derby to Rotherham Railway, which makes the first two of a total of 20 crossings before the river reaches the eastern edges of Danesmoor.

[4] This stretch of the river forms part of a £300 million redevelopment project called Chesterfield Waterside, which will provide housing and amenities in an area which is currently derelict land.

The river was diverted to run close to the railway to the west while 1.7 million tonnes of coal from the reserves under the park were removed by open cast mining between 1976 and 1981.

The move would transfer the responsibility for the tail goit from the Environment Agency to Rotherham Metropolitan Borough Council, who would then include it in their flood risk management plans.

Members of Ashfield Angling Club, which has fishing rights on the river near Orgreave, regularly catch chub, roach, barbel, and pike.

It was still in use in 1919, but by 1938, the river had been diverted along the course of the mill leat, and the main channel closed, to accommodate the ever-increasing railway sidings associated with Staveley Works.

Webster improved the facilities, to enable him to produce high quality steel wire, used to make cables, hawsers and rigging for ships.

[38] The River Rother is managed by the Environment Agency to mitigate flooding in the Catcliffe and Rotherham areas, through a series of regulators and washlands.

[39] Prior to 1958, flooding was a persistent problem near the lower reaches of the river, with Beighton, Catcliffe, Treeton and Woodhouse Mill particularly at risk.

Enlarging the channel of the Rother would have resulted in the peak flows reaching the Don earlier, effectively moving the problem of flooding downstream to Rotherham.

Levels within the park were carefully designed to allow it to flood in this way, and there are a number of sluices and flap gates so that stored water can be released back to the river in a controlled fashion.

However, there was a power failure at Canklow regulator, and the site had to be evacuated due to the threat posed by the possible breaching of the dam at Ulley Reservoir.

[39] The Meadowgate regulator was closed, and resulted in all four of the Rother Valley Country Park lakes flooding within the next 12 hours.

The regulator at Woodhouse is expected to be decommissiomed and replaced with a passive baffle or orifice plate once modelling of the site to determine their effectiveness has been completed.

Because of the high flow rates during flood events, a solution using 80 pre-cast concrete tiles, each 6.6 by 8.2 feet (2 by 2.5 m) and weighing 4 tonnes was adopted.

Upstands on the tiles ensure that there is suitable depth and velocity for fish over a wide range of river flows.

The Environment Agency stated at the time that they were working on a plan to allow the stuck gate to be raised, without damaging the rest of the structure.

[48] Laman Blanchard, writing in 1836, described the Rother as "a beauteous stream", and noted that chub, roach and perch were caught by fishermen who fished from its banks.

[49] The river did not suffer from the worst effects of the industrial revolution until the 1880s, when the development of coal mining on several of its tributaries resulting in a rapid deterioration in water quality.

Major upgrading of the Old Whittington sewage treatment works was carried out in the late 1980s and again in 1993, and included the addition of a nitrification plant to remove ammonia from the effluent.

Staveley Chemicals were producing chlorine and sodium hydroxide by electrolysing brine, and the water discharged from the site contained significant quantities of mercury and ammonia.

Mercury, in particular, is highly toxic to fish even in small concentrations, and in 1987, the works was discharging around 51 pounds (23 kg) per year into the river.

The Coalite site was manufacturing chemicals from the liquors produced as a by-product of the adjacent coking plant, and was discharging chlorinated compounds into the river.

Discharges from Avenue coking plant were diverted into a foul sewer in 1986, to enable them to be treated at Old Whittington treatment works.

The plant closed in 1992, but problems continued with phenolic oils leaching from the original storage lagoons into the river for several years after closure.

[55] A biological survey was carried out in 1993, near Rother Valley Country Park, and only seven types of invertebrates were found, all of which were highly tolerant to pollution.

A trial release of fish, funded by contributions from Rhone Poulenc, Coalite Chemicals and Yorkshire Water, was made in April 1994.

Brown trout, thought to have come from the River Hipper or the Barlow Brook, were also found in the Rother, and since these are much less tolerant to organic pollution and low oxygen levels, were a clear indicator that conditions were improving.

Like most rivers in the UK, the chemical status changed from good to fail in 2019, due to the presence of polybrominated diphenyl ethers (PBDE), perfluorooctane sulphonate (PFOS) and mercury compounds, none of which had previously been included in the assessment.